Difference: TransientWGMinutes (1 vs. 37)

• Gemini_LLP_meeting_notes_20210316.pdf: Gemini_LLP_meeting_notes_20210316.pdf

• Gemini_LLP_meeting_notes_20210309.pdf: Gemini_LLP_meeting_notes_20210309.pdf

Minutes 28/11/2018

Attending

Steve Schulze (moderator) Rachel Bruch, Maayane Soumagnac, Yi Yang, Avishay Gal-Yam (WIS), Adam Miller (Northwestern), Cristina, Leonardo (OKC), Christoffer Fremling, Anna Ho (Caltech), Dan Perley (LJMU)

Items

Bright stars appearing as transient

Some bright stars are being reported to the TNS as transients. This phenomenon has been noticed also in the RCF program. AMPEL is also affected. Example: ZTF18acgxbkd passed the RDF filter. Some of these objects exist in GAIA but have no proper motion or parallax measurement.

Reviewing ongoing projects

Maayane has been working lately on the object ZTF18abokyfk (2018fif) , a Type II-P supernova with early and nice UV light curve. Several spectra were obtained for this object (including a GEMINI spectrum which might need a re-reduction.). There are lines in the early light curve which could suggest the existence of flash features, however it is not conclusive enough. The Rabinak & Waxman model is going to be used to fit the early light curve. From this modelling and the early UV-light curve data, some progenitors properties can be extracted (e.g.: energy, radius…). Indeed, early UV-data allows to generate contraints on the total energy. If we compare this candidate to 13dqy, a preliminary conclusion is that 18fif is not a slow cooler as expected. There is however not enough SN-Type II-P with such detailed data to have a meaningful insight on the matter. Hopefully we will have more of these in the coming years!

If you have a suggestion or help to bring to this paper, please, talk to Maayane.

Marshal

UV data disappearance from the Marshal: some data (especially data added manually from e.g. UVOT) is disappearing on the marshal. To be investigated…

_Interesting Transients: _

…The partnership is on vacation! However there are still some rapidly rising transients popping up.

ZTF18acrewey: rised by about 1mag in a day. Same night SEDm spectrum: unfortunately spectrum is noisy. Object was at 19.5 mag.There is some continuum and spikes. No redshift. Tried to match them galaxy emission lines, not conclusive. If redshift is at 0.02: some of these features could match some flash features.

ZTF18acrdlrp: Rising relatively fast. Ia. No non-detection

ZTF18acrdwag: Moderatly rapid rise. SEDm triggered, was not really observed yet.

ZTF18achaqmd: Object has been rising for 2 weeks. SNIa. Luminosity g-band is at -20.25. Too luminous for a Ia SN. Object should be monitored more closely. Uncertainty on the redshift. Should get another spectrum.

ZTF18acrcyqw: Fast rising transient. Don’t know redshift. Core Collapse SN, probably. Photometry: rose a mag in a day. No features from SEDm.

There is still a chance of detecting young or fast rising transient even though we are not in the high cadence extra galactic survey anymore.

Have a great week!

Minutes 06/12/2018

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho (Caltech), Arial Goobar (OKC), Avishay Gal-Yam, Steve Schulze, Yi Yang (Weizmann), Dan Perley (LJMU)

Items

Operations update

-From Matthew’s email

1) The window frame of the filter exchanger controls the position of the EPMs at the instrument docking position. There has been some slippage so that not all of the EPMs are correctly positioned which is causing a filter exchanger error. A fix has now been put in place to prevent additional motion of the window frame.

2) We are tracking an issue with the cryocooler again with varying cryostat temperatures - again we may be looking at some contamination. We will try a new ambient clean out procedure today on the mountain as the weather looks bad for the next couple of nights.

Lin forwarded an email from Roger Stone last night (UT convention). The problem with the cooler is much more complicated than expected.

-Avishay noticed problems with the Marshal alert processing. He discussed this with Jakob Nordin (DESY) who experienced the same issue. Furthermore, UVOT data are occasionally disappearing from the Marshal. We are in touch with Mansi to solve this issue.

New Marshal feature

The Marshal has a new feature to display recently obtained spectra (http://skipper.caltech.edu:8080/cgi-bin/growth/spec_summary.cgi)

Last SWG Co-Chairs telecon

Two hours before the WG telecon, Ragnhild and Steve attended the SWG co-Chairs telecon. We spoke about the reference images, Year 2 and the new call for proposal for SEDm.

There was a miscommunication about the new strategy for the reference images. The new strategy aims to generate two sets of references: 1) a set of reference images with relaxed constraints, to build up instantaneous coverage and 2) the original (tighter) set of reference images. The new strategy was implemented before discussing it; however, there was no complaint about this change.

We briefly discussed the strategy for the second year of the ZTF partnership programme. We were all content with the high-cadence programme. The Ia group is also happy with the i' band survey. Anna is worried that no orphan afterglow was detected with the high-cadence programme, yet. If you have worries, too, please let us know ASAP so that we can discuss this at the next SWG Co-Chairs telecon.

The new call for SEDm time is out. The deadline is 20 December. Like for the first call, it is likely that we will submit multiple proposals. Please, prepare for the next telecon a summary of your SEDm usage and whether you are planning to re-submit your proposal. Will the RCF project continue in Year 2?

AAS (6-10 January 2019, Seattle, Washington)

Several group members will attend the meeting (https://aas.org/meetings/aas233). Avishay will present results about infant SNe, Ragnhild about PTF16eh, and Dan and Anna about AT2018cow. ZTF will have a splinter session on 8 January between 11 and 12.30. The scope of this session is to introduce the community to the alert stream. If you want to help, please email Matthew.

EWASS (24-28 June 2019, Lyon, France)

The upcoming EWASS will have 14 symposia, 41 special sessions and 9 lunch sessions. You can find more information at https://eas.unige.ch/EWASS2019/index.jsp. Our transient symposium (S1) will take place from 26 to 27 June. The abstract submission deadline is 3 March 2019.

Interesting transients

ZTF18acapyww: SLSN-I. The spectrum is similar to PTF10nmn. If the first data point is real, it could be reminiscent of the SLSN-I SN2018bsz (https://arxiv.org/pdf/1806.10609.pdf).

ZTF18acrewey: Fast-rising but low-luminosity (~-16) transient. The existing spectra do not allow us to classify the object. The latest Keck spectrum might show undulations. However, one could interpret that as an emerging p-Cygni profile at the wavelength of H-a. A further spectrum is needed to classify the object.

ZTF18abwlupf: Rise time of >70 days!

ZTF18abxbmqh: SLSN-II

Minutes 07/11/2018

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Mansi Kasliwal, Christoffer Fremling, Igor Andreoni, Kishaley De, Matthew Graham (Caltech), Christina Barbarino (OKC), Steve Schulze (Weizmann), Brad Cenko (UMd)

Items

Operations update

The problem with Archon#2 is fixed. The image quality of the six re-shimmed CCDs improved. However, the re-shimming of one of the CCDs was not as good as it could be. During the night from Tuesday to Wednesday, ZTF discovered ~400,000 alerts! It's good to see ZTF rocking again.

ZTF will switch from the high-cadence survey to the Galactic plane survey on 15 November.

ZTF has also finally reached full sky coverage in R band.

Project updates

-RCF project (Christoffer)

RCF has recovered all SNe that were detected by other surveys during the downtime. However, the sheer number of transients does not allow classifying all of them with SEDm. Christoffer will exclude objects from the RCF project that peaked during the downtime. Christoffer also showed the first results from the RCFs: 1) ZTF detects more CCSNe at z-14.

-ZTF18abukavn - rapidly rising Ic-BL SN (Anna)

The light curve of this object is quite remarkable: a rise time of ~2 days, a shallow-decline phase in r, i and z (lasting for about 10 days), followed by a decline phase and a plateau. Such an evolution is unusual for Ic-BL SNe. The rise is also seen in the UVOT filters, suggesting that the rise seen in optical bands is a genuine rise of the bolometric light curve and not a temperature effect. Swift/XRT and Chandra detected no X-ray emission. The Chandra limit is in the regime of other Ic-BLs without an accompanying GRB. The transient is also faint in the radio.

-ZTF18aaqeasu - a He-shell double detonation (Kishaley)

This transient was detected in the private Caltech data and MSIP data. This transient shows several peculiar features for an Ia SN. Light curve: 1) peak absolute-magnitude of only -18.2, 2) the light curve evolved like a normal Ia before maximum, but the late-time light curve is more similar to 91bg-like objects. Spectroscopic properties: 1) The first spectrum at TMAX - 10 days showed Fe and Ti troughs but no Si. 2) Around maximum light, the flux below 5000 AA is heavily suppressed due to line-blanketing. 3) Spectra obtained ~1 month after maximum light are similar to 91bg-like SNe. This conundrum of properties suggests that a He-shell detonation triggered the SN. Kishalay will submit the paper very soon, but a draft will be circulated in the next days.

Interesting transients

-ZTF18aainvic (type II): The transient seems to be a PTF14hls-like object. The spectrum shows almost no evolution over the past three months. The light curve looks so strange because the SN is detected in the reference images.

-ZTF18acebssa (infant SN): The transient was detected in the MSIP stream. A rapid SEDm spectrum shows a blue and featureless spectrum with strong He-II emission, suggestive for an SN that is less than ~24 hours old. Follow-up observations with Swift (approved), Gemini (approved) and LCOGT (pending) were initiated.

Minutes 31/10/2018

Attending

Ragnhild Lunnan (moderator, OKC), Christoffer Fremling, Igor Adreoni, Matthew Graham (Caltech), Cristina Barbarino, Jesper Sollerman and Leonardo Tartaglia (OKC), Rachel Bruch, Maayane Soumagnac, Avishay Gal-Yam and Steve Schulze (Weizmann), Suvi Gezari and Sjoert van Velzen (UMd), and Dan Perley (LJMU)

Items

Operations update

ZTF resumed science observations on 31 October. Only 12 of 16 CCDs were/are (?) operational because of a technical problem with Archon CCD controller #2. ZTF will continue with the high-cadence observations until 15 November. After that, the ZTF will switch to the Galactic plane survey. The high-cadence observations will resume in January/February.

Project update: Type II project (Weizmann)

Avishay gave a review about the Type II project. The project focusses on studying the SNe in their infancy, characterising the radiation process(es) during the plateau phase, and the transition phase where a SN changes from being powered by emission from hydrogen recombination to emission from the radioactive decay of Ni-56. The attached PDF file contains more details about individual sub-projects.

Interesting transients

ZTF18abgxjie (aka Daenerys of the House Nuclear Transients, First of Her Name, the Unburnt, Queen of the Andals and the Cosmic Transients, Khaleesi of the Nuclear Disks, Breaker of Chains, and Mother of Dragons [we wish]). The nuclear transient had a blue colour on its way to peak. After maximum, the light curve showed two plateaus with a duration of ~10 days each. The latest spectra show similarities to type II SNe. No narrow emission-lines are visible which would be indicative of CSM interaction and explain the raggedy light curve. It is difficult to put the transient in any category. The UV-optical colour is too red for a TDE, but the light curve is also odd for regular type II SNe.

1. ) Same night observations should be possible.

(1) Operations update
- making good progress on the focus system
- minor issue with the filter exchanger on Saturday night
- we lost half the night last night because of losing one of the power systems to the camera. so we were in backup mode, which meant losing a quarter of the quadrants. in total, last night's data is 3.5 hours at 75%
- public alert stream has started in earnest
- all MSIP alerts are now fully public and can be use by anyone.
- the embargo on image and catalog data remains until we do for the first public data release.
- the ATel has the relevant links

(2) SDSS-V + ZTF? (Thomas Kupfer)
- SDSS-V is still a few years away (2020, 2021) and has several surveys
- question came up if there’s anything SDSS-V could be interesting for the transient community or the SN community
- SDSS-V has a few fibers available for transient events
- at this point it’s mostly gathering interest and ideas
- redshifts and properties of host galaxies (long-term project where timing is not an issue)
- not so relevant ot the timescale of ZTF since we end in 2020
- what might be of interest is DESI because that is in our last year. It has 5000 fibers.
- idea from Shri to monitor a large set of binaries, where you keep track of the orbital phase and automatically take spectra at the phases you need

(3) Public alert stream
- part of the success of the project is how many people subscribe to the alert stream and use the data
- bright transient survey explicitly accounts for the fact that the MSIP survey is public
- everyone should think about how to take this into account for their own program

(5) Scanning
- Dan has put together a superluminous supernova filter. rather than employing a bunch of hard cuts on things, it adds or subtracts points based on various qualitative features about how it resembles a slow transient (each week of a rising light curve is awarded a point, points are awarded for host galaxies that are present or absent, being in a nucleus, starlike counterpart, and so on, and all these things are added together.) This seems to be working well.
- There’s been a lot more stellar junk recently, now that we're at lower Galactic latitudes
- The number of astrophysical things coming through has increased
- There is now a Galactic latitude annotation added to the Growth marshal that is on top of the avro packets, so you can try putting this cut in.
- The ML group is updating the RB score every now and then
- Also looking into cross-match with bright star catalog and include a distance to brightest star, since there are just too many artifacts next to bright stars
- Some issues with ghosting near bright stars
- Now you can delete sources by sending them to the garbage dump on the Marshal
- Delete the Science Validation filter? Or switch it to only listen to partnership alerts. It’s getting inundated with candidates and is slowing down the pages for people with other filters.
- Some people in Israel are still looking at the science validation filter because they have not finalized the infant supernova filter, although its development has been primarily through AMPEL.
- For sources saved in AMPEL, you can ingest them into the Marshal by avro ID

(6) First papers with ZTF data
- defer this to next week when there are more people from Stockholm and Weizmann on the call

(7) Interesting transients
IIn: seems to be very bright, still rising. Triggered Swift yesterday, today it was accepted. will have Swift data in the next 1-7 days.
http://skipper.caltech.edu:8080/cgi-bin/growth/view_source.cgi?name=ZTF18aavskep

ZTF18abokyfk: passed the infant SN filter a week ago have good Swift monitoring, and a very early spectrum early on, it’s a good fit to a blackbody

ZTF18abcfdzu: SN IIP quite luminous, long rise spectrum looks like a Ic supernova with hydrogen got a NOT spectrum at higher resolution, and it’s clear that H-alpha is actually resolved prediction is that the LC will keep going for a long time it’s higher redshift than 14c, so not clear if we would expect x rays or gamma ray

http://www.eso.org/sci/observing/phase1/p103/proposalsopen.html

NOAO (http://ast.noao.edu/observing/las-cumbres-observatory-2019a)
-Applying for LCOGT is problematic because they only have one 1-m class telescope in the Northern hemisphere.

Minutes 12/09/2018

Attending

Shri Kulkarni, Anna Ho, Christoffer Fremling (Moderator), Matthew Graham (Caltech), Maayane Soumagnac, Rachel Bruch, Ofer Yaron, Steve Schulze (host) (Weizmann), Adam Miller (Northwestern), Jesper Sollerman (OKC), Eric C Bellm (UW)

Items

Telescope Operation

The telescope has been running in a stable mode for the past few weeks. Now that the filter exchanging matters are dealt with, single-filter nights of observation are over and we are back to normal. Some engineering time is to be expected: the estimation is that about 1h /night will be dedicated to engineering check-ups.
The observatory will keep on exchanging filters while the telescope is in parking position.

Astroinformatics 2018

Machine learning for the public stream is expected to be available soon in October. Subscription to it is possible. Check this website: https://astroinformatics2018.h-its.org/Programme.html to re-watch live-streams for more information.

Discovery Claim and Twitter

Following some misunderstandings on twitter, it has been decided to clarify requirements to claim an object as a discovery (cf. forwarded attached file from Shri.) Given the multiple transient surveys, it is important to first check, on any known websites such as TNS, its existence and report it, in the case, it was not publicly declared. The term “independent discovery” cannot always apply in these cases especially if it has not been reported.
Regarding Twitter, it is now proposed that only published work, ATels and other released work will be broadcasted and advertised through Twitter, in order to avoid misunderstandings.

TNS data privacy

Regarding classified objects, data remains private. It has been suggested that maybe uncertain classifications could have spectroscopic data as public.

Catching-up Telecon

Shri suggested having a 15-minute telecon every now and then with at least one person from each institution. This would allow to e.g.: update on follow-up facilities, ideas and make the triggering of instruments more efficient.

Interesting Transient

-ZTF18abukavn (AT2018gep)
This transient was detected about three days ago. It is a very rapidly rising blue transient (about 4mag in just a few days, and now at 16mag). It is located in a host at redshift z=0.033. Host galaxy emission lines were detected. The transient is followed up since its discoveries by e.g. SWIFT-UVOT & XRT, SMA, VLA, and LT. While it was declared “Blue Featureless” at first, a broad absorption feature appeared (cf. screenshot from Ana’s presentation), like in AT2018cow, however, narrower and broader. Another hotter feature developed yesterday. Avishay suggested it seems consistent with a type Ic or a type Ic-BL SN.
Follow-up plans include possible high-resolution spectrographs.

A Slack Channel is now dedicated in the “ZTF-Transient” working group for this object: https://ztftransient.slack.com/messages/CCSEH9P29

-ZTF18abokyfk
Monitoring of this slow cooling transient is ongoing.

WISeREP - 2

Ofer presented the new version of WISeREP which was released about two weeks ago. The idea of WISeREP is to provide an archive of SNe data. The new release includes the database of the previous version and now the multiplicity of photometric, spectroscopic and phase data. Registered users can now report and upload data themselves (e.g.: phase information, photometry, comments, spectroscopy). A better bulk download has been implemented and allows for more format options. Also, plots have been improved and allow now aggregation of several plots. The handling of names is more efficient and more complicated queries are now possible. (Such as showing spectra of two different objects in the same plot).
The old WISeREP is now going to be frozen.
ZTF data remains proprietary. A discussion is now opened to whether there should be an automatic ingestion of data from ZTF on a regular basis (however remaining proprietary).
You can now register and join your research group: https://wiserep2.weizmann.ac.il/

Have a nice week!

Minutes from 20/09/2018

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Christoffer Fremling, Igor Andreoni and Shri Kulkarni (Caltech), Cristina Barbarino, Jesper Sollermann, Leonardo Tartaglia and Suhail Dhawan (OKC), Rachel Bruch, Steve Schulze and Yi Yang (WIS), Adam Miller (Northwestern), and Dan Perley (LJMU)

Items

Operation update

There was no technical problem with the telescope. However, the Marshal had problems with the alert ingestion. This is a known issue, and it should be fixed.

At the team meeting in spring, we discussed how to increase the usage of SEDm. Since then, the usage ramped up. There are no statistics on whether people are more trigger friendly or whether this is due to new SEDm programmes. SEDm is still accepting new programmes.

Marshal update

The name resolver is in place. You can now also search for objects using non-ZTF names.

Releasing spectra of the RCF project

Shri decided to release the SEDm spectra from the RCF project. Christoffer is preparing a document about that. There were still open questions that need to be discussed with other groups.

Swift Science Meeting (2-3 October 2018)

Christoffer will give a talk about ZTF. If you have results from your Swift observations or how your science case benefits from Swift, please prepare a slide.

Proposals

A series of proposals are in preparation.

Shri: Swift proposal for young stellar explosions; Keck/DBSP programmes for classifying objects

Mansi: transients in the local Universe

Mattia Bulla: RRM spectroscopy of infant SNe with X-shooter at the VLT

Yi Yang: spectropolarimetry of infant SNe with FORS2 at the VLT

Ragnhild Lunnan: Late-time spectroscopy of SLSNe with the VLT

Adam Miller: Follow-up of SNe in equatorial fields with LCOGT. However, LCOGT has a dedicated SN key programme.

Christoffer Fremling: nebular spectroscopy of (stripped?) core-collapse SNe

Interesting transients

-ZTF18abucxcj: Transient close to the nucleus of PGC58181. The spectrum shows features that resemble an AGN but also transient HeI emission lines that are not present in the SDSS spectrum. It could be a TDE or a SN with very late flash features.

-ZTF18abukavn: New observations showed that the object developed into an Ic-BL supernova. The rapid rise is atypical of the general population of broad-lined Ic supernova, but the SN resemble properties of a rare class of stripped-envelope SNe PTF16asu (Ic-BL) and PTF12gzk (Ic). Anna recovered emission from the host/transient in the radio with the VLA. The flux level is comparable to the level expected from the host. Additional VLA observations are needed to look for variability.

-ZTF18abvvmdf: Possible flash features (HeII), but the spectrum is not as blue and featureless as expected for an infant SN

-ZTF18abvzdvj: Nice flash spectrum.

-ZTF18abwkrbl: Flash spectroscopy.

-ZTF18abwlsoi: Flash spectroscopy

Minutes 24/10/2018

Attending

Ragnhild Lunnan (OKC, moderator), Christoffer Fremling (Caltech), Cristina Barbarino, Jesper Sollerman (OKC), Maayane Soumagnac, Rachel Bruch, Steve Schulze (Weizmann)

Items

SEDm

SEDm had a few smaller problems. If you triggered SEDm and the OB status was "executed", but the data didn't show up on the Marshal, please contact Christoffer. Next week, the Marshal will have more extended status information for SEDm.

Project updates: ZTF18aalrxas (SN IIb)

Christoffer showed a few plots from his work. The luminosity is similar to the SN-IIb 2011dh, but ZTF18aalrxas is less luminous than Type IIb SN 2013df. Matthias Ergon used his model for 2011dh (https://arxiv.org/pdf/1408.0731.pdf) to model the light curves and spectra of ZTF18aalrxas. Christoffer will use the model by Nagy & Vinko (https://www.aanda.org/articles/aa/pdf/2016/05/aa27931-15.pdf) to model the full light curve (shock cooling + Ni-56). The light curve of ZTF18abffyqp/SN2018dfi is similar to ZTF18aalrxas. It might be interesting to apply Matthias's model on that SN, too. This needs to be discussed with Weizmann.

Next week, we will hear more from Anna about ZTF18abukavn and from Avishay about the Type-II project.

SEDm queue

The beginning of the night is oversubscribed. If you have targets for the rest of the night and you need data, please assign them to SEDm.

Interesting transients

-ZTF18abrzcbp (SLSN-I): The spectrum shows similarities to SN2007bi and PTF12dam. OKC plans to get a higher S/N spectrum with the NOT.

-ZTF18abshezu (SLSN-I): The light curve might show a drop between ~NOW-25 days. The SLSN is so bright that we can monitor the spectrum with SEDm.

Minutes from 06/09/2018

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Mansi Kasliwal and Christoffer Fremmling (all Caltech), Cristina Barbarino, Leonardo Tartaglia, Suhail Diawan and Jesper Sollermann (all OKC), Rachel Bruch and Steve Schulze (all WIS), Adam Miller (Northwestern), and Dan Perley (LJMU)

Items

Operations update

There was no technical problem. Additional latches were installed that allow changing the filter at any given position. In the optimal case, ~5 additional images could be taken per night.

The occasional drift in declination is due to a bug in the TCS.

Christoffer developed a pipeline to process the SEDm acquisition images.

EWASS 2019

The European Week of Astronomy and Space Science (EWASS; http://eas.unige.ch/EWASS2019/call.jsp) is the largest annual meeting of astronomers and space scientists in Europe. Next year, it will take place in Lyon from June 24 to 28, a few months after the MSIP DR1. It would be a fantastic opportunity to gather the transient community and discuss results from ZTF and other surveys. We are proposing a symposium with 6x1.5-hour blocks. You can find more information at

https://docs.google.com/document/d/14wf006M7g1rvTcBI2qrHJT_T_8fLsF7nt68o-fTqCJE/edit?usp=sharing

If you want to participate in organising the conference, please contact Steve (steve.schulze@weizmann.ac.il). Note, if you want to get involved in organizing the meeting, you can’t give a talk. We imposed this rule to avoid conflicts of interest.

Telescope proposals

We briefly discussed proposals for Swift (deadline: 27 September), ESO (27 September) and NOAO (1 October).

Swift (https://swift.gsfc.nasa.gov/proposals/swiftgi.html)
-Shri plans to submit a proposal for young SNe. -Ragnhild plans to submit a proposal for SLSNe.

ESO (http://www.eso.org/sci/observing/phase1/p103/proposalsopen.html)
-OKC/SESN plans to resubmit their X-shooter proposal for RRM observations of young SNe and nebular spectroscopy. -OKC/Ia intends to submit a proposal for specpol with FORS2. -WIS is thinking about submitting a ToO proposal for MUSE-AO to resolve the immediate environment around very bright SNe.

NOAO (http://ast.noao.edu/observing/las-cumbres-observatory-2019a)
-Applying for LCOGT is problematic because they only have one 1-m class telescope in the Northern hemisphere.

ePESSTO

Jesper mentioned some political issues with ePESSTO. We need to follow up on this issue at one of the next meetings.

Marshal

We briefly discussed our wishlist with Mansi.

Interesting transients

ZTF18abimhfu (unknown type): The transient has a double-peaked light curve. The first peak had a width of ~ 10 days. The lack of late-time g’ band data does not allow us to conclude whether the second peak is panchromatic (similar to 1987A-like SNe) or whether it is only visible in red bands (similar to the second peak in type Ia SNe).

ZTF18abqyvzy (unknown type). The supernova is close to its maximum, but the spectrum is still blue and featureless.

ZTF18abkmbpy (gap transient): Thanks for additional LT data, the decline is now even more extreme than before. The nature of the transient is still unknown.

ZTF18abhxidx (possible Ic SN): The peak luminosity of ~-19.5 is exceptionally high for an Ic SN, but it is similar to the luminosity of Ia SNe. Was the SN misclassified?

Minutes from 22/08/2018

Attending

Rachel, Maayane (Weizmann), Ragnhild, Cristina, Leonardo, Emir, Ariel, Jesper (OKC), Dan (Liverpool), Anna, Shri (Caltech), Adam (Northwestern)

Items

Operations/Marshal

There was some issue with focus (leading to a number of out-of-focus candidates on the scanning page) but that has been resolved.

There was also an issue with a several-days delay in candidates appearing on the scanning page. Not sure whether that has been resolved, but Matthew is out of town.

Update from Shri: working towards developing more transparent guidelines for sharing data. Would like to understand what the plans are for the partnership fields.

Interesting Transients

ZTF18abhxidx: classified as SN Ic by SNID, but light curve is quite luminous for a Ic

ZTF18abpetsj: very rapidly evolving light curve, but it’s at a very low Galactic latitude RCF will be changed soon for a 10º latitude cut

ZTF18abokyfk: passed the infant SN filter a week ago have good Swift monitoring, and a very early spectrum early on, it’s a good fit to a blackbody

ZTF18abcfdzu: SN IIP quite luminous, long rise spectrum looks like a Ic supernova with hydrogen got a NOT spectrum at higher resolution, and it’s clear that H-alpha is actually resolved prediction is that the LC will keep going for a long time it’s higher redshift than 14c, so not clear if we would expect x rays or gamma ray

SN2018bcc (presentation by Emir)

-fast-rising type Ibc supernova caught early by the ZTF survey

-it has a 6-day rise time in the rest frame

-for these fast-rising Ibn’s, rise is very uncommon if not completely unique

-Emir et al. are working on a paper on this object

White Dwarf Tool (presentation by Shri)

-a tool to cross match Gaia with the daily alert service

-start at rico.caltech.edu

Minutes from 22/08/2018

Attending

Ragnhild Lunnan (OKC, moderator), Christoffer Fremling and Shri Kulkarni (Caltech), Ariel Goobar and Jesper Sollerman (OKC), Maayane Soumagnac, Rachel Bruch, Avishay Gal-Yam, Steve Schulze and Yi Yang (Weizmann), Brad Cenko (UMd), Adam Miller (Northwestern), and Melissa Graham (UW)

Items

Operations

P48 is working fine. In the next two weeks, the plan for the SEDm fixes will be finalised.

Marshal

The SN supergroup was added to the RCF project.

SEDm

SEDm is currently short on targets for the second half of the night due to missing reference images. We discussed whether filler programmes should be limited to ZTF targets or ZTF-related science. If you have suggestions, please speak up!

Interesting transients

ZTF18abmasep: SLSN-I, detected well before maximum light

ZTF18abkmbpy: fast and faint, possible gap transient

ZTF18abncimo: The early light curve shows an atypical transition from shallow to steeply rising. A SEDm observation is scheduled for tonight.

ZTF18abokyfk: The SN was detected within 24 hours after explosion. It is another example where we managed to get follow-up observations with Gemini, P200 and Swift during the same night. Unfortunately, the spectrum is blue and featureless with a hint of HeII in emission.

ATel

As ZTF is routinely detecting and rapidly following up infant SNe, Avishay proposed to report a showcase via ATel to show ZTF's capabilities. A draft of the template will be circulated in the next days.

Early Science paper

Ragnhild presented the first results from her ZTF SLSN paper. Two objects were outstanding:

ZTF18aajqcue (SLSN-I): The spectrum is similar to 2007bi, but the colour of the SLSN is red. Is it due to dust or is the SLSN intrinsically red?

ZTF18aavrmcg (SLSN-I): The light curve shows a faster rise than any known SLSN. The latest non-detection puts deep limits on the presence of a bump which was observed in other SLSNe and which was speculated to be ubiquitous!

Minutes from 15/08/2018

Attending

Ragnhild Lunnan (OKC, moderator), Maayane Soumagnac, Steve Schulze and Yi Yang (Weizmann), Adam Miller (Northwestern), Christoffer Fremling (Caltech), and Dan Perley (LJMU)

Items

Operations update

Nobody had news about the status of P48.

Conference slides

If you gave a presentation at the team meeting, don’t forget to upload your slides to the wiki and add a brief summary (2 sentences).

Papers

Maayane submitted a paper about the SN-IIn PTF12glz (arXiv:1808.04232). In this paper, she presents the theoretical framework for her project on type IIn SNe with ZTF.

Ragnhild compiled the lightcurves for the ZTF SLSN paper.

Christoffer's paper on ZTF18aalrxas is also progressing well.

Marshal

Ragnhild presented a wishlist for the Marshal (https://zwicky.tf/30t). We concluded that it would be good to invite Mansi to a future telecon to discuss these suggestions in more detail.

Proposals

There are several proposal deadlines at the end of September. We loosely discussed which proposals might be useful. We postponed a more in-depth discussing to a later telecon.

Note, Israel has several big holidays in September. If there is interest for joint proposals, we should not delay decisions to the very last moment.

Lowering the quality cuts of reference images

We continued the discussion whether it is useful to lower the cuts of the reference images and whether we should obtain reference images for the secondary grid. Loosening the quality cuts and obtaining reference images of the secondary grid primarily affects ToO science programmes. For us, it would be important to finish the primary grid before starting the secondary grid. Matthew pointed out via email that reference images are also needed to generate matchfiles. In conclusion, changing the requirements is not straightforward. The group coordinates will continue discussing this subject at the next ZTF SWG Co-Chairs Meeting on July 25.

Transients

ZTF18aautopz (SLSN-II): The SN has a strange spectrum. It shows a bulge in the blue and flat emission component in the red.

ZTF18abkmbpy (Ca-rich transient): The spectrum shows Ha and Hb in absorption, but also a CaII in emission at 7400 AA. Who is in charge of gap transients in the working group?

Minutes from 27/06/2018

Attending

Ragnhild Lunnan (OKC, moderator), Anna Ho, Christoffer Fremling (Caltech), Cristina Barbarino, Francesco Taddia and Jesper Sollerman (OKC), Maayane Soumagnac, Avishay Gal-Yam, Steve Schulze and Yi Yang (Weizmann), Adam Miller (Northwestern), Ginny Cunningham (UMd), Adam Miller (Northwestern), and Dan Perley (LJMU)

Items

Operations update

Last week, the GRB and the neutrino ToO programmes were triggered. Everything went smoothly. The technical issue with the pointing remains. It is still not clear what causes it. Maybe, the TCS?

Publication policy for electronic circulars (e.g., ATel, GCN, TNS)

No objections were raised. Ragnhild will email all members for the final call. Afterwards, the policy will be passed on to the publication board.

Early Science papers

Christoffer tested the quality of the image subtractions and the photometry with PS1 images as reference. In general, the quality is good. However, he found differences of <~0.1 mag in the r- and i-band photometry for the type Ia SN ZTF18abauprj. Hence, projects that require precision photometry need P48 reference images.

Jesper mentioned that the ZTF photometry of the Ibn SN ZTF18aakuewf and recent TNG photometry do not match. Christoffer will look into that.

We will set up an area on the TWiki to store information about which papers are in preparation.

Projects

Since our science filters are running, people started to have new project ideas. Don’t forget to update the Projects page on the TWiki.

Scanning

Anna asked who would be interested in a general scanning effort. Jesper mentioned that OKC has many requests for scanning, taking care of SEDm and watching P48. He proposed that we discuss this topic at the collaboration meeting in August. Avishay suggested to decide on a scheduler before the next telecon and start scanning on a voluntary basis.

Interesting transients

We could not avoid speculating about the nature of AT2018cow. Is it a SN, a blazar, or a form of GRB?

After the short intermezzo, we discussed a few ZTF transients. The infant SN filter is finally working. Within one week, 4 infant SNe were detected: ZTF18abauprj (Ia 91T-like), ZTF18abcptmt (II, possibly flash-features), ZTF18abckujq (unknown), ZTF18abdbysy (dusty type II?). Rapid follow-up observations with DBSP, SEDm, UVOT, WHT were triggered for all of them.

Action point for next week

We need to discuss who is going to give the talk on behalf of the SWG at the group meeting in Stockholm.

Minutes from 07/06/2018

Attending Anna, Adam Miller, Brad Cenko, Christoffer, Dan Perley, Maayane, Mansi, Matthew Graham, Ofer, Rachel, Ragnhild, Shri, Thomas Kupfer, Lin Yan, Ginny Cunningham

Contents

(1) Operations Update (Matthew), (2) SDSS-V (Thomas Kupfer) (3) Public alert stream (Shri), (4) SEDM (Christoffer), (5) Discussion on scanning & filters, (6) First papers, (7) Interesting transients

tl;dr
- If you run into issue with SEDM, make sure you report these to the team
- The public alert stream has started in earnest
- There will soon be a Galactic latitude annotation added to the marshal
- Now you can delete sources by sending them to the garbage dump on the Marshal
- We are considering deleting the science validation filter, since commissioning is over and people should focus on being complete for their particular science interest using the partnership data.

(1) Operations update
- making good progress on the focus system
- minor issue with the filter exchanger on Saturday night
- we lost half the night last night because of losing one of the power systems to the camera. so we were in backup mode, which meant losing a quarter of the quadrants. in total, last night's data is 3.5 hours at 75%
- public alert stream has started in earnest
- all MSIP alerts are now fully public and can be use by anyone.
- the embargo on image and catalog data remains until we do for the first public data release.
- the ATel has the relevant links

(2) SDSS-V + ZTF? (Thomas Kupfer)
- SDSS-V is still a few years away (2020, 2021) and has several surveys
- question came up if there’s anything SDSS-V could be interesting for the transient community or the SN community
- SDSS-V has a few fibers available for transient events
- at this point it’s mostly gathering interest and ideas
- redshifts and properties of host galaxies (long-term project where timing is not an issue)
- not so relevant ot the timescale of ZTF since we end in 2020
- what might be of interest is DESI because that is in our last year. It has 5000 fibers.
- idea from Shri to monitor a large set of binaries, where you keep track of the orbital phase and automatically take spectra at the phases you need

(3) Public alert stream
- part of the success of the project is how many people subscribe to the alert stream and use the data
- bright transient survey explicitly accounts for the fact that the MSIP survey is public
- everyone should think about how to take this into account for their own program

(4) SEDM update (Christoffer)
- SEDM has been working very well, we’ve been getting a lot of classifications for RCF
- Wasn’t able to respond well to the GBM trigger, but that may have been a weather issue, at least for the first night.
- Fields were pretty far to the west, and there are apparently restrictions on where P60 can point, which wasn’t communicated. It was technical issues with cables having trouble pointing to certain elevations.
- If you have any issues with SEDM, make sure you send it into the team.

(5) Scanning
- Dan has put together a superluminous supernova filter. rather than employing a bunch of hard cuts on things, it adds or subtracts points based on various qualitative features about how it resembles a slow transient (each week of a rising light curve is awarded a point, points are awarded for host galaxies that are present or absent, being in a nucleus, starlike counterpart, and so on, and all these things are added together.) This seems to be working well.
- There’s been a lot more stellar junk recently, now that we're at lower Galactic latitudes
- The number of astrophysical things coming through has increased
- There is now a Galactic latitude annotation added to the Growth marshal that is on top of the avro packets, so you can try putting this cut in.
- The ML group is updating the RB score every now and then
- Also looking into cross-match with bright star catalog and include a distance to brightest star, since there are just too many artifacts next to bright stars
- Some issues with ghosting near bright stars
- Now you can delete sources by sending them to the garbage dump on the Marshal
- Delete the Science Validation filter? Or switch it to only listen to partnership alerts. It’s getting inundated with candidates and is slowing down the pages for people with other filters.
- Some people in Israel are still looking at the science validation filter because they have not finalized the infant supernova filter, although its development has been primarily through AMPEL.
- For sources saved in AMPEL, you can ingest them into the Marshal by avro ID

(6) First papers with ZTF data
- defer this to next week when there are more people from Stockholm and Weizmann on the call

(7) Interesting transients
IIn: seems to be very bright, still rising. Triggered Swift yesterday, today it was accepted. will have Swift data in the next 1-7 days.
http://skipper.caltech.edu:8080/cgi-bin/growth/view_source.cgi?name=ZTF18aavskep

Minutes from 13/06/2018

Attending

Ragnhild Lunnan (OKC, moderator), Anna Ho, Mansi Kasliwal, Christoffer Fremling and Shri Kulkarni (Caltech), Emir Karamehmetoglu and Leonardo Tartaglia (OKC), Maayane Soumagnac, Rachel Bruch, Avishay Gal-Yam, Ofer Yaron and Steve Schulze (Weizmann), Brad Cenko (UMd), and Dan Perley (LJMU)

Items

Operations update

Nothing problematic. Engineering runs were carried out to improve the guiding system and hence the quality of the image subtractions. Additional engineering runs are scheduled to improve the telescope focus.

MoU with Assaf Horesh

Assaf will bring in radio expertise that our working group is currently lacking. We discussed the possible conflict with Anna Ho's and Alessandra Corsi's VLA efforts. However, all of them have collaborated with each other in the past. No further concerns were raised. It was suggested that the proposal should be passed on after Matthew's concerns are addressed.

Early science papers

Caltech:
-Christoffer: He will write a paper about the double-peaked IIb SN ZTF18aalrxas.

-Anna Ho would like to write a paper about the Ic-BL SN ZTF18aaqjovh. VLA observations revealed a source with constant flux and flat SED at the SN position. Both properties are unexpected for a SN. A detailed analysis is ongoing to understand the nature of the radio emission.

OKC:
-Emir would like to write a paper about the Ibn SN ZTF18aakuewf. Special about this Ibn is that it was detected before maximum and that late-time spectroscopy exists as well.

-Ragnhild would like to write a paper about the 4-5 SLSNe detected with ZTF. Hindering this project is that the reference images are affected by the transients. It was suggested to use PS1 or SDSS as reference images.

WIS:
-Three possible projects: a) flash-spectroscopy of an infant type II SN, b) a sample paper about type II SNe with early observations, and c) building up a sample of well-observed IIn SNe to look for aspherical CSM. The latter project is unlikely because of the limited timescale.

Do others have plans, too?

Christoffer offered his photometry code to produce light curves.

Please make sure that you have enough man-power to finish such any early science project before the proposal deadlines in autumn.

Future of the SV filter

WIS needs another week to finalise their infant SN filter. Are all other filters working? If you have problems, please discuss your issues with us. Other filter developers can help you.

Mansi and Avishay passionately discussed the future of the SV filter and how to share transients between different filters. The current capabilities of the Marshal for group management and object sharing are not satisfying and in disagreement with what was promised at the ZTF collaboration meeting in spring. After the telecon, it was agreed on to implement batch-adding users to filters (like Mansi was describing for telescope groups). Please contact Ragnhild, if you want to part of this group.

Minutes from 20/06/2018

Attending

Ragnhild Lunnan (OKC, moderator), Anna Ho, Mansi Kasliwal, Christoffer Fremling, Shri Kulkarni (Caltech), Cristina Barbarino, Jesper Sollerman and Leonardo Tartaglia (OKC), Maayane Soumagnac, Rachel Bruch, Ofer Yaron, Steve Schulze and Yi Yang (Weizmann), Suvi Gezari and Brad Cenko (UMd), Zach Golkhou (UW), Adam Miller (Northwestern), and Dan Perley (LJMU)

Items

Operations update

The pointing can sometimes be off after the telescope stops slewing. The engineering team has been investigating this issue during the past week. ZTF started to observe more frequently in i' band. No alerts have been issued yet, due to the lack of reference images.

ATel/GCN/TNS policy

Although we only managed to discuss this close to the end of the telecon, it is a very important issue. Ragnhild circulated a link to the draft of the working group policy (commenting enabled): https://docs.google.com/document/d/1GqPkQHaLEzToHkRTqAFqFT7gd83ChhMIB0eo6K5G3TE/edit?usp=sharing

and the ZTF publication policy (linked on front page of TWiki): https://docs.google.com/document/d/1PhVCEVlUuqOB_W1puWi4xxuNm-LW7hNFRH-WohVIrkc/edit.

Why is this important? ATels and GCNs are strategic tools that enable us to draw attention to peculiar transients, establish leadership, or to brand an object (if the transient could be found in the MSIP stream shortly after). This can be very useful to obtain observing time in the future. However, this also means that others might scoop you in writing the paper. Shri mentioned that this strategy has been very useful in the GRB field.

Please read the draft for the ATel/GCN/TNS policy and try to answer why and when you would like to write an ATel/GCN/TNS? Since we are one collaboration, such circulars should be circulated among the SWG before submission. How many hours before the submission deadline needs to be decided. What do you think?

SEDm

SEDm is accepting imaging triggers. Such triggers could be very useful for young and fast transients, to trace the brightness and colour evolution. We also discussed whether SEDm would be a good instrument for that. Observing with LCOGT is challenging because of its limited resources in the Northern hemisphere. One open question is which observations would be critical? We get g and r from P48. Are simultaneous ugri observations important or is a shot in u and i sufficient? Note, you can only submit requests for one epoch at a time.

Early science papers

If you need light curves for the early science papers, please contact Christoffer. He will produce light curves for your objects. Franck improved the IPAC photometry pipeline. Christoffer hinted that Franck could also re-run the IPAC pipeline on selected targets, which could be interesting for transients with MSIP data, where we can't access the data.

Instrument papers

The instrument papers are will be submitted soon. Everybody is encouraged to become a co-author and also to contribute to Matthew Graham’s and Eric Bellm’s papers.

Supergroups

You will be able to add the supergroup to your science programme through the account page on the GROWTH Marshal. Don’t get discouraged if you cannot see the feature at the moment. The last bits are being put in place. Note, if people join/leave the supergroup, the supergroup needs to be re-ingested!

GROWTH follow-up email list

AT2018cow is in the ZTF footprint, but no alert has been issued, yet. Nonetheless, there has been a lively discussion on the GROWTH mailing list. Isn’t this the ideal occasion to join?

SEDm tzar and tzaritza

It is not in place, yet. Tomorrow, there will be a dedicated tzar telecon.

ZTF team meeting in Stockholm

Don’t forget to register for the team meeting in August. The deadline is on 1 July.

http://agenda.albanova.se/confRegistrantsDisplay.py/list?confId=6506

ZTF summer school

If you want to learn how to work with ZTF, join the ZTF summer school

http://www.ztf.caltech.edu/page/summer-school

Minutes from 16/05/2018

Attending

Christoffer Fremling (OKC, moderator), Anna Ho, Lin Yan, Matthew Graham and Shri Kulkarni (Caltech), Cristina Barbarino, Leonardo Tartaglia and Suhail Dhawan (OKC), Maayane Soumagnac, Rachel Bruch, Ofer Yaron, Steve Schulze and Yi Yang(Weizmann), Jakob Nordin and Robert Stein (DESY), Angie van Sistine (UMd), and Melissa Graham (UW)

Items

SEDm

Our workhorse instrument is becoming a problem child. Besides the problems with the lenslet array, SEDm is also understaffed. Shri asked Jesper to identify a person who could help Nadia. Jesper suggested that several people should get involved. We will continue discussing this issue next week.

Operations update

Last week, we either lost time due to bad weather or technical problems. The problems with the shutter RFIs could not be fixed, yet. Also, two engineering runs took place to resolve DIQ issues. A third run is scheduled for tomorrow night.

Alerts

IPAC will apply low-level cuts to lower the number of bogus sources. Matthew will update us on the details in the next days.

Photometry in the alert package (reported via email by Adam Miller)

Frank finalised the analysis of the differential photometry in the alert packets. The photometry is now more accurate as well as more robust against bad pixels and noise. The difference-image PSFs are also cleaner. Updates were effective on the night of May 11 UT.

MoUs

We discussed the MoUs with SNIFS and Assaf Horesh. Unfortunately, the concerns regarding the co-authorship policy have not been resolved. The Ia-cosmology group is encouraged to provide concrete suggestions. Nobody had comments about the MoU with Assaf Horesh. We postponed the discussion until next week.

catsHTM

Maayane presented her recent paper (http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1805.02666) about a new software tool to perform efficient cone-searches and catalogue cross-matches. It can be a powerful tool to vet candidates.

catsHTM is available for python (cone-search) and Matlab (cone-search and cross-matching). You can run the software on a desktop computer, assuming 2.1 TB of free hard-disk space for all catalogues. You can retrieve the python package from https://github.com/maayane/catsHTM and the Matlab package from https://webhome.weizmann.ac.il/home/eofek/matlab/. To retrieve the catalogues, contact Maayane (maayane.soumagnac@weizmann.ac.il) and Eran (eran.ofek@weizmann.ac.il).

Interesting targets

ZTF18aahpbwz: Luminous Ib SN. The spectrum is hotter and richer in features than regular Ib SNe at a similar phase.

ZTF18aalrxas (IIb). It is one of the first well-sampled ZTF SNe. The light curve is still rising and reached m(r)~19/M(r)~-18.1. A new spectrum is needed to track the spectral evolution.

ZTF18aaqjovh (Ic-BL): A NOT spectrum was obtained. The shape of the spectrum is identical to the SEDm spectrum! This shows that SEDm can deliver reliable spectra for Ic-BLs.

Minutes from 09/05/2018

Attending

Ragnhild Lunnan (OKC, moderator), Anna Ho, Christoffer Fremling, Matthew Graham, Scott Adams, Shri Kulkarni (Caltech), Cristina Barbarino, Francesco Taddia and Leonardo Tartaglia (OKC), Maayane Soumagnac, Ofer Yaron, Steve Schulze and Yi Yang (Weizmann), Angie van Sistine, Ginny Cunningham and Brad Cenko (UMd), Melissa Graham and Zach Golkhou (UW), Adam Miller (Northwestern), and Dan Perley (LJMU)

Items

Operations update

960,000 alerts were produced with the filter exchanger during the night from Tuesday to Wednesday (8-9 May)! No technical problems were encountered. The days before the weather was bad. There were problems with subcomponents due to RFI. The errors were sometimes not reproducible.

SEDm

There have been problems with one of the cameras and the cooling system.

RB system

The new system is in place. Note, there is no record of the version of the RB software in the alert package. We agreed that it would be good to have an easily accessible document that keeps track of updates on the software system.

Several good candidates had an RB score of ~0.2-0.35 using the new RB software. We discussed whether this is extremely low or OK.

The current RB software is trained on high Galactic field. It will need some revision for the Galactic plane. It needs to be decided how this should be done.

Alert readiness review

The general feeling of the board is very good. There are concerns about the readiness of the brokers: Antares, ALeRCE and Lasair. It was suggested to set up some sort of a document for liability issues.

ZTF papers

We discussed Matthew’s and Eric’s drafts. If you write any section in Matthew’s paper, please add your name to those sections, in case there are questions.

MoU between ZTF-Ia and SNtwin teams

We had a longer discussion about the co-author policy which we couldn’t resolve. We concluded to invite Ariel Goobar to the next telecon to discuss this issue.

How to deal with MSIP alerts?

This is one of the most delicate issues. How should we proceed if we want to follow-up MSIP alerts? We agreed that it would be good to have a formal document. After the telecon, there has been a lively discussion covering many aspects.

A new feature on the Marshall

The Marshall displays from which data streams the photometry was compiled (partnership, MSIP, Caltech). The photometry page shows this information for each data point. The remaining question is: What do 1 and 2 stand for?

Minutes from 02/05/2018

Attending

Ragnhild Lunnan (OKC, moderator), Anna Ho and Christoffer Fremling (Caltech) Cristina Barbarino, Francesco Taddia, Jesper Sollerman and Leonardo Tartaglia (OKC), Maayane Soumagnac, Rachel Bruch, Avishay Gal-Yam, Steve Schulze and Yi Yang (Weizmann), Brad Cenko (UMd), Melissa Graham and Zach Golkhou (UW), and Kirsty Taggart and Dan Perley (LJMU)

Items

Filter

We are at a critical stage of the filter development (not in a good sense). It’s impossible to test a filter on the same data set and in real-time, using the Marshall. To be able to discuss this more easily, we opened the channel #alert-filter in the ZTF-transient workspace (ztftransient.slack.com)

To get more people involved in the filter development, here is a summary of individual efforts:

- Sjoert has a local version of the GROWTH Marshall and a set of alerts. This allows him to check how specific settings change his alert stream in real-time.

- Caltech uses the ZTF SV and SLSN filters. Both filters are identical but differ in their thresholds. (If you didn’t know, Christoffer is in charge of the ZTF SV filter)

- Team Weizmann is collaborating with Berlin to design a filter using AMPEL.

Christoffer can provide some python code to work with the alert stream. Alerts can be retrieved from Dima (duev@caltech.edu). Dan has developed a python tool to simulate SN light curves and generate avro dictionaries (https://github.com/dperley/ztf-filter-test).

The ML learning group rolled out a new version of the RB software. It should be in place at the beginning of next week. This may reduce the number of artefacts from bright stars. Implementing a bright star catalogue is planned (GAIA DR2?).

ZTF update

There have been problems with the filter exchanger. At some point the robot didn’t put any filter in the beam anymore, leading to many alerts from white band data. Observing conditions have been poor in the past nights and are expected to remain crappy.

ZTF-transient slack channel

Join our slack channel:

https://join.slack.com/t/ztftransient/shared_invite/enQtMzUzMzQ5Njc0MjkyLTdlODg3N2NjYzA3YTg2YjAwNWFmOGY4MTkwMzlkZGRiZjg5ZGEzMGJmZDJlZWNjZmZmMDk3ZWRlODU3NDY4Njg

Zooniverse

The ML group is running a campaign to quantify artefacts on each chip of the ZTF camera. You can help them on Zooniverse (https://www.zooniverse.org/projects/rswcit/ztf-rb-project/classify).

ZTF instrument papers

The ZTF collaboration is planning to submit a series of instrument papers to PASP for a focus issue. Due to the submission deadline (1 June), comments should be sent before 11 May. Links to the individual papers can be found at

http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/ZtfPapers

Please contact Ragnhild if you are not listed as a co-author on the relevant papers. Note, some drafts are password protected. Contact the first authors if you need access to the papers.

Marshall features

The developers have worked on permission issues. The feature to add multiple people at the same time has not been implemented, yet. We also discussed having a website summarising which transients were shared and transferred. A ticket was submitted.

MSIP RCF project

The bright transient project from the MSIP alert stream has started. The workload is manageable: ~50 candidates per day. Contact Christoffer if you want to participate.

Upcoming observing runs

Anna is participating in a P200 observing run. Jesper is involved in an observing school (led by Sweden) at the NOT. If you have intriguing transients, don’t forget to contact them.

A few of us triggered LCOGT on northern targets. Unfortunately, no observation was executed. The problem is that LCOGT has limited resources in the northern hemisphere. We need to keep that in mind when triggering LCOGT next time.

Interesting transients

ZTF18aalrxas: The light curve has a fast and a slow component. There were speculations whether it could be similar to a IIb SN or to KSN2015K (Rest et al., 2018). Additional spectra are needed to reveal the nature and redshift of the transient.

ZTF18aahhbkj: It’s a luminous type II SNe. Broad Balmer features have developed. No narrow Balmer lines detected that could indicate a IIn.

ZTF18aakuewf: Interesting is the short rise and its blue spectrum on the decline. Anna will try to get a spectrum with DBSP. If unsuccessful, Weizmann plans to trigger Gemini.

ZTF18aaitbcm: A transient in a faint galaxy. A big telescope is needed to classify.

ZTF18aajviok: Rising for >~2 weeks.

Minutes from 25/04/2018

Attending

Ragnhild Lunnan (OKC), Anna Ho, Lin Yan, Christoffer Fremmling and Shri Kulkarni (Caltech), Cristina Barbarino and Jesper Sollerman (OKC), Maayane Soumagnac, Rachel Bruch, Ofer Yaron, Steve Schulze and Yi Yang (Weizmann), Brad Cenko (UMD), Melissa Graham (UW), Adam Miller (Northwestern), and Dan Perley (LJMU)

Items

Thesis proposal update from Anna Ho

Anna is working on relativistic transients. Her thesis has three components i) search for afterglows of GRBs and dirty fireballs, ii) studying local Ic-BL SNe, and iii) explore photometric signatures of central-engine activity. Her interest in Ic-BL SNe overlaps with OKC. Anna and OKC will discuss how to separate sub-projects and how to collaborate.

5-week MSIP project

Shri proposed a time-limited project that would search for bright (e.g., >18.5-19 mag) transients (not variable stars) in the MSIP stream. High-confidence transients would be rapidly circulated to the public via the TNS and ATels (not one ATel per candidate). The general transient community is encouraged to classify the targets, but we would also classify targets with SEDm. The expected number of candidates per day is ~10-40. This project would end when the MSIP stream goes officially online. The goal is to generate visibility for the ZTF, to familiarise the community with the data stream, and also to help us to train the machine-learning efforts.

Brad had concerns because it means we need to allocate manpower for a service to the community that we are not bound to provide. There were also other issues that would need to get sorted out first. Nonetheless, volunteers, who would like to get involved, should email Christoffer. The envisioned starting date would be next week or earlier.

We also discussed issues that need to be sorted out to minimise the extra work: 1) how trustworthy is the photometry, 2) how can we extract the last non-detection in an easy way, and 3) adding a “Report to TNS” button on the Marshall (Christoffer will work on that).

Filters

We all agreed that it is difficult to stabilise the science filter. In fact, most filters are not working (anymore). Christoffer pointed out that Sjoert van Velzen (UMD, ZTF BH group) managed to design a powerful filter for the ZTF BH group. Christoffer will ask him whether he could give a small presentation during the next telecon.

Artefacts close to bright and saturated stars are still ending up in the ZTF umbrella programme. We discussed possible solutions, e.g. increasing the distance to bright stars.

Interesting transients

ZTF18aalrxas – a fast transient of unknown nature. The SEDm spectrum shows two emission features that could be Ha and Hb at z = 0.

Minutes from 18/04/2018

Attending

Ragnhild Lunnan (OKC), Anna Ho, Lin Yan and Christoffer Fremmling (Caltech), Cristina Barbarino, Francesco Taddia, Leonardo Tartaglia and Jesper Sollerman (OKC), Maayane Soumagnac, Steve Schulze and Yi Yang (all WIS), Melissa Graham and Zach Golkhou (UW), Robert Stein (DESY), Dan Perley (LJMU), and Brad Cenko (UMD)

Items

Operations update

There were no technical issues. However, the filter of our programme showed no new candidates for a couple of days. The problem was likely caused by changes to our filter. The BH-AGN group had candidates.

Early science results

Eric Bellm is writing a paper about the ZTF survey. The paper will also contain early science results. Ragnhild prepared a document summarising our efforts and highlighting ZTF18aaayemw and ZTF18aabybkt.

Ragnhild also updated our ATel. The most recent results will be reported in the ATel. For earlier results, we will refer to the TNS. The ATel is back with the board.

Interesting targets

ZTF18aahhbkj (SN-II; Mpeak ~ - 19.5). What is interesting about the object is that it showed a blue continuum with low amplitude undulations for more than a week. We requested one epoch of UVOT photometry to measure the peak of the spectrum. The observation was carried out on 22 April.

ZTF18aahgakg (unknown, Mpeak <-17.6). That's a real oddball. The transient occurred in a blue-compact dwarf galaxy. The NOT spectrum showed a blue continuum with a kink at 6400 AA. Absorption features and possibly a broad emission feature were visible, but their nature is unknown. An additional spectrum was requested. We were awarded 3 UVOT epochs to measure the peak of the spectrum in the UV and how it evolves with time. 2/3 OBs were executed (20 and 23 April).

Minutes from 11/04/2018

Attending

Ragnhild Lunnan (OKC), Anna Ho, Christoffer Fremmling, Matthew Graham and Shri Kulkarni (Caltech), Francesco Taddia, Leonardo Tartaglia and Jesper Sollerman (OKC), Maayane Soumagnac, Avishay Gal-Yam, Ofer Yaron, Steve Schulze and Yi Yang (all WIS), Melissa Graham (UW), and Adam Miller (Northwestern)

Items

Operations update

Last week, problems with the shutter timing were detected. While the telescope is moving, the shutter is not closed. That led to an increased number of streaks. Technicians are working during daytime to fix this problem. There have also been a few issues with the filter exchanger, hence observations in only one filter.

ATels

We have the OK to submit our Atel. Since the March targets are quite old, we decided to include all classified objects detected with the partnership programme. Please make sure that your spectra are uploaded to the Marshall. Anna will check which of them were detected during the partnership time.

How to release bright targets from the MSIP survey?

We had a long discussion whether it is possible to distribute bright targets from the MSIP survey to the community before the official start. It was proposed that we could release MSIP targets brighter than 18th magnitude after the (alert?) readiness review, at the end of the month. The brightness cut would be relaxed with time before the public gets full access.

Interesting targets

ZTF18aahmxqa (Ib): Christoffer checked the quality of the SEDm spectrum to the higher-resolution P200 spectrum when the object faded to r~18.8. The similarity is remarkable. That's reassuring for the RCF project and all our SEDm programmes.

ZTF18aahhbkj is a SLSN-II candidate. The object has been rising for >20 days. Current brightness is ~-19.5, quite high for a regular SN-II.

Observing runs

If you have an interesting target for follow up, don’t forget to add it to the observing queues.

Scanning

OKC and WIS have carried out intensive scanning during the past weeks. In the next days, the schedule for the next weeks will be more formalised.

Umbrella programme

The ZTF SV programme will be the umbrella programme. A new feature was added to the Marshall to add batches of users to science programmes.

Zoo-universe

Ashish would like to add a few nice examples of bogus sources to the tutorial. If you spot some, please send him the IDs.

Minutes from 28/03/2018

Attending

Ragnhild Lunnan (OKC), Anna Ho, Lin Yan, Christoffer Fremmling and Matthew Graham (Caltech), Cristina Barbarino, Francesco Taddia, Jesper Sollerman (OKC), Maayane Soumagnac, Ofer Yaron and Steve Schulze (all WIS), Ginny Cunningham (UMD), and Melissa Graham (UW)

Items

Operations update

Since last week, we are observing in g’ band. The constraints for the alerts were relaxed to m=22.5 mag and S/N = 5 as agreed upon at the ZTF meeting. The goal is to detect more bogus sources to train the ML classification. Reference images were taken during the first nights, but due to bad weahter this process could not be finished, resulting in only a small number of alerts. We should expect more transients in the next days.

In the next weeks, 1-2 nights will be allocated to engineering. Matthew will inform us when these nights will be.

The readiness report for the filter exchanger is awaited.

MoU with Adam Miller

OKC and WIS are all in favour to let Adam Miller join.

Marshall

We continued our previous discussions how to overcome the user restrictions of the individual science programmes. One suggestion is to install an umbrella programme that gets automatically fed by the individual science programmes. Another one is to install a super-group that everybody can join. The developers of the Marshall are currently deciding on which approach is easier to implement.

Regarding transferring sources, everybody can offer and accept transfer requests.

To share an object, choose on the object page “Transfer To Another Programme“ and mark the check-box for sharing.

Scanning

We are gearing up for an intensive scanning campaign that will last several of weeks. The goal is to classify as many as possible bogus sources to train the ML classification on the noisier alert stream. The goal is to detect fainter and younger transients.

WIS and OKC will coordinate the scanning activities. Everybody is encouraged to participate. A document with a set of instructions is in preparation and will be put on our TWIKI site later. Scanning will be done through the SV programme.

S/G classifier is implemented and awaits final verification.

Targets

Recently, Melisa’s team had a 5-night observing at APO. The spectra of the objects listed below were uploaded to the Marshall.

NAME DATE TYPE

ZTF18aaewugy 180319 SNII

ZTF18aaayemw 180319 SNII

ZTF18aabsygo 180319 Galaxy

ZTF18aabwaeo 180319 unclear

ZTF18aabtaor 180320 SNIa

ZTF18aabybkt 180320 SNII

ZTF18aabyhlc 180320 SNIa

ZTF18aaccycc 180320 Galaxy

ZTF18aabstmw 180321 SNIa

ZTF18aabufhw 180321 SNII

ZTF18aagrebu 180323 SNIa

ZTF18aagrcir 180323 SNIa

ZTF18aagrcfl 180323 SNIa

To prepare for the RCF programme, Christoffer classified several publicly known SNe with SEDm. The classification of SN2018amc is potentially interesting. It could be a 1987A-like object at -87 days, but it could be a regular type II SN.

Observing proposals

Yi Yang re-submitted a proposal for spectropolarimetry of infant SNe with FORS2 at the VLT.

Jesper’s team re-submitted a ToO/RRM proposal for the VLT X-shooter and a ToO programme for nebular spectroscopy.

Lin Yan is currently preparing a Keck proposal for SLSNe.

Update from the NOT (La Palma)

A few weeks ago, ALFOSC got fried by lightning. All issues are fixed, and the instrument is back at the NOT.

Minutes from 14/03/2018

Attending

Ragnhild Lunnan (OKC), Anna Ho, Lin Yan, Christoffer Fremmling and Matthew Graham (Caltech), Cristina Barbarino, Emir Karamehmetoglu and Leonardo Tartaglia (OKC), Maayane Soumagnac, Steve Schulze, and Yi Yang (all WIS), Brad Cenko (all UMD), and Melissa Graham (UW)

Items

Operations update/news

Not much happened. P48 was mostly weathered out. On Friday, the g'-band filter was mounted, but the system assumed it was r' band. That led to 2 million false alerts which were removed from the system. Such a mistake will not happen when the filter exchanger is in place. Note, these images will not be processed by IPAC. The raw data can be retrieved from the ZTF archive. Unfortunately, their meta data is incorrect.

On Friday, the different alert streams (Caltech, partnership, public) will come together. We will start with one week of r' band, followed by one week in g' band.

MoUs for Dan Perley

We discussed Dan's MoUs. There were no major objections. Brad had a question about the data rights, which he will follow-up. Please read the two MoUs Ragnhild circulated and email the respective contact persons.

Active transients/follow-up

Due to the bad weather, there were no new exciting targets. ZTF18aabywzu was flagged as a SLSN candidate. However, its rise is atypically short, and the source had an outburst in 2009 and 2016. It's listed as a CV/DN in variable star catalogues.

We briefly discussed the follow-up efforts of ZTF18aaayemw, ZTF18aabybkt and ZTF18aabstmw. Three UVOT epochs were obtained for ZTF18aaayemw and ZTF18aabybkt each and 1 epoch for ZTF18aabstmw. There is a problem in uploading the light curves to the Marshall. Christoffer said that it has something to do with the filter IDs. We informed Mansi about the bug.

Upcoming observing runs

Melissa has 5 half-nights at APO next week. Please fill out the follow-up schedule. Her run starts on the 19th and not on the 18th as indicated on the Marshall. There is also an upcoming Keck observing night. However, the forecast is bleak.

Recently, the Nordic Optical Telescope was struck by lightning. Sadly, the electronics of the ALFOSC camera were fried and ALFOSC is currently unavailable. This means we will not be able to get optical spectra from the NOT.

A note about UVOT observations. UVOT only allows you to choose a filter mode from a pre-defined list. Brad mentioned that the mode 0x223f is ideal for SN science. It secures photometry the six broadband filters and is optimised for the UV (http://www.swift.psu.edu/operations/mode_table.php?hexval=223f). If you want to use this mode, mention it in the time justification.

Marshall

Ragnhild set up a page on the TWIKI to keep track of bugs and features that would be desirable (not to confuse with desirable bugs ): http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/TransientMarshalWishlist

The AGN group has generated a similar list: http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/AMPELChannels.

If you want to volunteer to code for the Marshall, contact the Marshall team.

Minutes from 01/03/2018

Attending

Ragnhild Lunnan (moderator), Leonardo Tartaglia, Cristina Barbarino, Francesco Taddia (OKC), Maayane Soumagnac, Avishay Gal-Yam, Yi Yang (Weizmann), Ginny Cunningham (Maryland), Melissa Graham, Eric Bellm (UW), Christoffer Fremling, Mansi Kasliwal, Anna Ho (Caltech)

Contents

(1) Operations Update (surveys, filters, SEDM, permissions; Christoffer), (2) Operations Update (alerts; Eric), (3) Continuation of marshal discussion (access permissions), (4) Active transients (young CC, Ic-BL) + follow-up resources (including the GROWTH India telescope)

(1) Operations Update: Surveys, Filters, SEDM, Permissions (Caltech; Christoffer)

- i-band observations have been going well, not aware of any major issues, although no targets have been making it through the filters. will likely keep going until we see targets, since the point is to validate that filter.

- SEDM is operational again, but last night we tried to trigger and it didn’t work. looking into this. you are encouraged to try and trigger both photometry and spectroscopy

- Plan for next week: a few more commissioning related tasks, but the weather looks bad

- Caltech TAC has met, haven’t received survey plans yet. Looking at a soft start to operations in the next week or so

- Filter exchanger isn’t operational yet, haven’t cleared it for unattended exchanges during the night. Plan is to do 2 weeks of g- or r-band and then switch. Will use cadence plans but instead of switching filters in the night, will stick to whatever filter is mounted that night.

- Start of the survey: they will turn on permissions for the various surveys. There will be three modes: (1) the Caltech time, (2) the MSIP survey, (3) the partnership time. Everybody on this telecon will see MSIP and partnership time. Details of how to access the MSIP part is still an open question. In principle that data becomes available after one year. Once we’re operating in that mode we’ll have a better understanding of the issues and how we will solve them.

(2) Operations Update: Alerts (UW; Eric)

- Alerts have been fairly stable since the start of the test run. They’ve been up and available with only one or two interruptions.

- In the near term, will be moving host machine to a more favorable position in the network, which will have a number of operational advantages in terms of data transfer and having support from university IT system enabling authentication for the various streams so that we can enforce permissions on Caltech, MSIP, partnership time

- Currently the alert stream is coming from IPAC, not UW understanding is that we’re ingesting the

- IPAC is making preliminary & very high cuts on S/N, close to 10-sigma

(3) Follow-up on Marshal Discussion

- During the first science validation run, we ran into the issue of not being able to access a transient. For example, if someone sent a link to say “what do you think?” the target might not be accessible to the recipient. Or, someone on an observing run might not be able to see the page of a target they were supposed to follow up.

- Essentially, you have to be subscribed to a certain filter (a certain science program) in order to see a transient. However, the working group has reached a general consensus that we would like to be able to see a transient saved under a science program that we are not a member of.

- It’s in the consortium rules that transients should be public.

- Mansi suggests defining a broader program (something like “young supernovae”) as an umbrella for all of the science programs relevant to this working group. Then, once a source is classified, you can transfer it to a more science-focusd program. For example, you can imagine a source starting off as a “young supernova” and then being transferred to the Ia or core-collapse science program. The point is to prevent thousands of sources from flooding any one program.

- Anyone can be a member of multiple science programs (so, all transients are accessible to everybody, as long as they sign up) and it’s up to the PI to control who is in the group.

- Avishay: the filter should not be coupled to access. You should be able to subscribe to a filter and see only a certain set of sources, but then still access a source within a different filter that you are not subscribed to. If we want an umbrella program, it has to be all extragalactic transients, and will include those classified, and those not classified. If this cannot be implemented, then we have to decouple filtering from access, because transients within the consortium are public. A transient and its basic characteristics derived from the public consortium data should be visible to everybody without asking for permission.

- Mansi: you can query IPAC for photometry for any source. The only information added by the marshal is follow-up data.

- If you want someone in a different working group to see your transient, then you can transfer it to their program via the marshal.

- To be continued...

_(4) Active transients:

ZTF18aaayemw:

- This transient is 3 weeks old and detected in all the UVOT filters

- Narrow H-alpha

- We have some photometry from the WISE telescope, which Steve uploaded to the marshal but is currently not appearing. There’s another r-band point (18.4 mag) which is more or less the same time as the Swift observations, and there will be another epoch of Swift observations three days from now. Will have another run on the 1-meter in a week.

- Christoffer tried to trigger P60 for photometry

- Once it’s public, can trigger LCOGT

- This has highlighted the lack of geographic diversity (and robustness to weather!) of our resources

- This is likely some sort of Type II supernova between IIN and IIL. There were a couple of previous examples from PTF where the source stayed blue and featureless for a couple of weeks past maximum, before developing a photospheric spectrum. The case Avishay remembers had very low velocities.

GROWTH India telescope

- Has been delivered, they’re still commissioning, will maybe ready in a few months

- The majority of the time is dedicated to transient follow-up

- The MOU with GROWTH is specifically with EM counterparts to gravitational waves, and not on supernovae. If there’s interest from the supernova group it will have to be a separate MOU

- Christoffer has talked with Varun about making the subtraction pipeline.

ZTF18aaacwya: - Ic-BL, trying to observe but weather has not been cooperating. Christoffer checked the P48 photometry and it’s currently 19th mag.

Minutes from 01/03/2018

Attending Ragnhild Lunnan (moderator, OKC), Lin Yan, Mansi Kasliwal, Christoffer Fremmling, Matthew Graham (Caltech), Cristina Barbarino, Jesper Sollerman (all OKC), Ofer Yaron, Steve Schulze and Yi Yang (all WIS)

Items

Operations update/news

Last week we had poor weather conditions. However, this was a good opportunity to test the filter exchanger. The commissioning made good progress, but it will take 2-3 weeks before it's finished.

The Alert system is still in commissioning. That means we can expect to see improvements in the RB score and the S/G separation. Note, the latter is currently not trustworthy.

During the next week, the three streams (Caltech, MSIP, and partnership fields) will come together.

Active transients/follow-up

There are upcoming observing runs at APO, NOT, and P200. Check if you need new observations. Mansi also has a large time allocation for Swift. The program will expire at the end of the month. So, don't hesitate to request Swift observations. If you trigger Swift, use here program code: 1316157 and send her an email.

Two new transients caught our attention:

ZTF18aabybkt is a young SNe with deep limits 2 days before the first detection. APO, Gemini, P200, and SEDm were triggered for spectroscopy. Swift was triggered for imaging. Please let us know if you can get photometry.

ZTF18aabstmw is a rising transient. SEDm revealed that is it faint Ia SN. Las Cumbres Observatory independently classified the transient. It's a 91bg-like Ia SN around maximum light. We considered triggering Swift, but we are not sure if Swift observations are still important at this SN phase. Input from Ia experts would be very welcome.

Old transients: We got the three UVOT epochs ZTF18aaayemw.

The Marshal

Please test all features of the Marshall. If you encounter a problem, write to contact_growth@astro.caltech.edu.

We briefly discussed new bugs:

- MP checker wasn't working. It wasn't clear what causes the issue.

- the Alert button didn't work

and also a features that would be nice to have

- a switch to not see saved and removed objects on the scanning page

- a counter to see the total number of transients on the scanning page

- an option to share objects.

Scanning schedule

This issue is particularly important for the infant SN and the fast-transient groups. At the moment it is difficult to decide on the scanning strategy. We need more good nights to get a better feeling for the quality of the stream and number of transients we have to expect every night.

Upcoming telescope proposals

There are several upcoming proposal deadlines: ESO 28 March, NOAO 2 April, and there is also an internal Caltech deadline.

Christoffer is going to re-submit his Keck proposal for nebular spectroscopy and his LCOGT proposal to monitor Ibc SNe. Caltech is also going to submit a proposal for Gemini to target young SNe.

OKC will re-submit an ESO/X-shooter proposal for RRM observations of young SNe and nebular spectroscopy.

Weizmann also has interest in submitting an ESO proposal for infant SNe. Yi Yang will re-submit his spec-pol proposal for ESO/FORS2.

We should continue discussing this topic to avoid internal competition and make sure that we are properly geared up for 2018B, e.g., do we need more resources to monitor the light curve evolution of SNe (a general LCOGT program?)?

In the spirit of the upcoming proposal deadlines, Jesper mentioned that their NOT program was extended for three additional semesters. Congratulations!

ZTF team meeting

We run out of time and only briefly discussed this issue. Christoffer is going to give a talk about our efforts at the ZTF meeting. If you cannot attend the meeting, please let us know if you have issues that we should bring up or pay more attention to.

Minutes from 21/02/2018

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Lin Yan, Christoffer Fremmling, Matthew Graham (Caltech), Cristina Barbarino, Francesco Taddia, Leonardo Tartaglia and Jesper Sollerman (all OKC), Maayane Soumagnac, Avishay Gal-Yam, Ofer Yaron, Steve Schulze and Yi Yang (all WIS), Virginia Cunningham and Brad Cenko (UMD), and Angie Van Sistine (UW)

Items

Alert package (important)

Until the end of today, you can make suggestions what should be added to the AVRO alerts. The link below summarises which information is currently included.

https://github.com/ZwickyTransientFacility/ztf-avro-alert/blob/master/docs/schema.md

It was already proposed to add 1) the Scorr from ZOGY, 2) 16/32-bit images instead of 8-bit JPEGS for the thumbnails, and 3) a list of all objects within a certain radius of the transient. Please write to Matthew <mjg@caltech.edu> if you have further suggestions.

ZTF status

The g' band mini-survey took place at the end of last week. All reference images were taken. Unfortunately, only a few images were obtained during the other nights because of bad weather. The idea is to have another night in g' band tonight (Pacific time).

In the next days, the i'-band filter will be commissioned, followed by an i'-band survey. Matthew will let us know when this mini-survey will start.

The real-time alert system/alert ingestion is still in commissioning. In his last email Matthew wrote "Alerts are flowing into the marshal from IPAC - however it seems that none are making [it] past the marshal filters - there have been too few alerts in the last few nights."

ZTF SV targets

Two targets caught our attention: ZTF18aabcwtr and ZTF18aaayemw. Both targets have been followed up with various telescopes. We made a new website on the TWIKI to keep track of the follow-up efforts. If you want to contribute to the campaigns or if you are already involved in them, keep your information updated at

http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/TransientTargetsZTFSV.

Follow-up resources

SEDm is currently offline. The cable to the guide camera is broken.

Mansi has an approved Swift GO programme that is valid until 1 April. Use the programme ID 1316157 when triggering Swift. Also, let her know if you plan to use Swift.

Marshal

Christoffer re-analysed the light curve of ZTF18aabcwtr (ipac_fpipe.eps). Most notable is the stark difference between his light curve and the IPAC light curve. The reason for this is that the SN is also detected in the ZTF reference images that were used by IPAC to generate the light curve. In addition, the number of data points differ significantly. Christoffer is investigating why not all data were ingested by the Marshal.

Ofer asked why there is a significant scatter in the light curves on the Marshal. Christoffer said that the problem is unrelated to the quality of the subtractions. He suspects a software issue.

The Marshal doesn't allow us to see which science groups exist and who are the PIs. We want to store the information of all science programmes of our working group on the TWIKI, to get around this issue. Please add your programme information at

http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/TransientWGProjects.

We also discussed Avishay's proposal (Program_structure_within_the_extragalactic_Marshal_#8211_proposal.docx) on how to overcome the permission restrictions on the Marshal. His proposal met approval by many participants. Ragnhild is going to follow this up.

At last week's Marshal QA session it was proposed to re-ingest existing alerts. The date has not been specified, yet.

ATels

An ATel about the recent classifications is in preparation.

Naming of ZTF targets

This is an item I forgot to report last week. The long ZTF names are not preliminary; they are final. That means we need boost our memory capabilities. No cheating allowed!

Minutes from 14/02/2018

Attending

Ragnhild Lunnan (moderator, OKC), Christoffer Fremmling, Matthew Graham (Caltech), Cristina Barbarino, Emir Karamehmetoglu, Francesco Taddia and Jesper Sollerman (all OKC), Maayane Soumagnac, Ofer Yaron, Steve Schulze and Yi Yang (all WIS), Brad Cenko (UMD), and Angie Van Sistine, Melissa Graham and Eric Bellm (UW)

Items

ZTF status

It looks very good! ZTF is working and detecting transients.

From Friday to Sunday, ZTF has discovered several hundred thousand transients. Unfortunately, since then observing conditions have been poor. Tonight we will have a final run in R band. Starting from Friday, we will continue with g band (planned nights: Fr-Sa, Sa-Su, Su-Mo). After that, a few nights will be allocated to engineering. Please add your follow-up resources and the contact person to the TWIKI (http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/TransientWGAcidTest) and to the calendar on the Marshall (http://skipper.caltech.edu:8080/cgi-bin/growth/master_schedule.cgi). Melissa Graham has an observing run with APO on Saturday. She will circulate details how to pass candidates to her team.

Because of the bad weather, no data were obtained with the P200 and SEDm. Please, make use of SEDm during the remaining time of the SV run.

The Marshall is ingesting alerts, but there are problems with the filtering. Everybody is working on fixing that. The star/galaxy separation is still in progress.

Transients

ZTF has detected several transients. You can find a summary of all transients at http://skipper.caltech.edu:8080/cgi-bin/growth/list_sources_growth.cgi?programidx=0. The NOT secured a spectrum of ZTF18aabcwtr (Ic) http://skipper.caltech.edu:8080/cgi-bin/growth/view_source.cgi?name=ZTF18aabcwtr. ZTF18aabasml is in the NOT queue for tonight.

During the telecon, a very important question was raised. Did ZTF detect all transients discovered by other surveys or are we missing any? If you have done this exercise, please share this information with the Working Group.

Scanning

If you participate in scanning, please add your name to the calendar: http://skipper.caltech.edu:8080/cgi-bin/growth/master_schedule.cgi. It is very important to avoid gaps, especially on the weekend.

The scanning page also has a feature to remove asteroids, fakes, and stars. Don't hesitate to make use of this option. The ML group needs these objects to improve the ML algorithm.

Marshall

There will be a QA session on Thursday at 11 o'clock Pacific time (https://zoom.us/j/9281727495). You will hear more about the design strategy of the Marshall and upcoming new features. You will also have the opportunity to discuss current problems with the Marshall interface.

Communication within the science group

The following is very important for the success of our working group. Our Working Group is very diverse. That means we will have several science groups on the Marshall. This diversity can affect our ability to have a good overview of the entire field. In the worst case, you might miss the transients you are interested in! We briefly discussed possible solutions. 1) Everybody would become a member of all science groups by default. You will have to opt out if you want to leave a group. 2) There could be a supergroup. As the survey progresses, we will get a better idea how to tackle this issue. That also means that we need your input to make the best possible decision. For the time being, add/update your science programme on the TWIKI (http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/TransientWGProjects), add the name of your science group and who is in charge of designing the filter.

Minutes from 07/02/2018

Attending

Ragnhild Lunnan (moderator, OKC), Christoffer Fremmling (Caltech), Cristina Barbarino, Emir Karamehmetoglu, Francesco Taddia and Leonardo Tartaglia (all OKC), Maayane Soumagnac, Avishay Gal-Yam, Ofer Yaron, Steve Schulze and Yi Yang (all WIS), Brad Cenko (UMD), and Melissa Graham, Eric Bellm and Zach Golkhou (UW)

Items

ZTF test run update/planning

The telescope is fully operational. Unfortunately, the weather was less cooperative. That delayed obtaining the reference images. Our first chance to detect transients will be on Thursday. The delay also affects the scheduling of the P200 runs. There will be at least one night at the end of the week. SEDm is fully operational and at our disposal to classify transients.

If you haven't done it, add your follow-up resources to the TWIKI.

The Marshal

The GROWTH Marshall is online. The invitations were circulated yesterday. If you haven't registered, write to contact_growth@astro.caltech.edu (subject: GROWTH marshal). The core features (defining filters, adding candidates, scanning, and uploading spectra) are working. Please read Mansi's instructions about the GROWTH Marshall.

If you want to participate in scanning, go to http://skipper.caltech.edu:8080/cgi-bin/growth/master_schedule.cgi and chose "Assign Scanning Schedule". Sign up for multiple nights, if you like scanning. Or scan with your colleagues. Four eyes see more than two! NOTE, there is a technical problem that doesn't allow you to sign up at the moment.

We also discussed the different items from Mansi's email. A key issue was how to organize our science program on the Marshall. We all agreed not to put up borders, which is quite unusual these days, and collect all transients in a single group. According to our individual preferences, we will define sub-groups to separate the wheat from the chaff.

ATels

Today, the first ZTF ATel was published (http://www.astronomerstelegram.org/?read=11266). We discussed whether/if/how we should report discoveries and follow-up efforts. In the long run, we should avoid wasting time on reporting discoveries. They will be automatically reported to the TNS (not clear whether this feature is operational at the moment). Everything that is automatically pushed to the TNS is flagged as private.

The science coordinators (Ragnhild, Christoffer, and Steve) will present a possible author policy for ATels at the next telecon.

ML telecons

Maayane encouraged everybody to participate in the ML telecons. The link to the doodle is https://doodle.com/poll/yvt23xv2p99b797z. Don't get confused by the dates. Only the time slot is important.

Schedule for next week

-Transients. Finally!

-ATel author policy

Minutes from 31/01/18

Attending

Christoffer Fremmling (moderator, Caltech), Anna Ho, Matthew Graham, Shri Kulkarni (all Caltech), Cristina Barbarino, Ariel Goobar, Emir Karamehmetoglu and Jesper Sollerman (all OKC), Maayane Soumagnac, Avishay Gal-Yam, Ofer Yaron, Steve Schulze and Yi Yang (all WIS), Virginia Cunningham and Brad Cenko (all UMD), and Melissa Graham, Eric Bellm and Zach Golkhou (UW)

Items

ZTF Swift proposal

Unfortunately, the ZTF proposal was rejected. Brad (acting Swift PI) pointed out that Swift is dedicated and prepared for ZTF. If Swift observations are needed, we should not hesitate to submit Swift DDTs.

With that being said, the next proposal deadline for Gemini, VLT and many other telescopes will be in March/April. We should use the upcoming ZTF test run to show that the science observation started and that ZTF opens a new and unprecedented avenue in optical time-domain astronomy.

First ZTF ATel

The first ATel is about to be issued. More news will be circulated in the next days.

GROWTH Marshall

The invitations to the GROWTH Marshall should be sent out within the next days, before the ZTF test run starts.

ZTF test run

As pointed out by Shri, next week will be the acid test for ZTF. The test run will start on Wednesday and last between 5 to 7 days. Each night, a few patches in the sky with a size of 3000-4000 degree^2 will be observed four times within a two-hour time window. The observations will be done in R band. The fields will be covered by SDSS, but also extend to the Galactic plane. There is no final decision on which fields should be targeted. If you have suggestions, contact Matthew Graham.

The P200 run will start at the tail of next week and continue the week after. Contact Christoffer if you are interested in helping analysing data.

Please add your follow-up resources to http://noir.caltech.edu/twiki_ptf/bin/view/ZTF/TransientWGAcidTest.

Minutes from 24/01/18

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Christoffer Fremmling, Kishalay De (all Caltech), Cristina Barbarino, Francesco Taddia, Ariel Goobar, Leonardo Tartaglia (all OKC), Maayane Soumagnac, Avishay Gal-Yam, Steve Schulze, and Yi Yang (all WIS), Brad Cenko (all UMD), and Melissa Graham (UW)

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First ZTF supernovae detected

Christoffer classified transients with the P200 telescope that were vetted by the M/L group and had multiple detections. In total, he secured spectra of 20 objects with a magnitude between 18 and 19. Four of the transients turned out to be Type Ia SNe. These results represent the first detections of SNe with ZTF.

Machine-learning group

Maayane proposed to the M/L group to have bi-weekly telecons to discuss the progress of the M/L project and the needs of the observer. These telecons will be at a time that is suitable for all ZTF partners. Further information will be given in the ZTF newsletter.

Star/galaxy separation

Ragnhild mentioned in a previous email that there had been a discussion about which information should be added to the ZTF alerts that will be valuable to distinguish stars from galaxies. Currently, the suggestion is to list the three closest PS1 sources within 30", including griz magnitudes, distance, and S/G score for each object. During the telecon, we discussed whether these criteria are sufficient. Brad suggested that we should check which lessons we have learnt from (i)PTF. Avishay pointed out that information from galaxy catalogues should be incorporated, like in (i)PTF. That would be very useful for nearby transients, which can easily have angular distances from their hosts of more than 30".

SEDm proposals

Ariel said that we should hear about the results from the white-paper call in a couple of weeks.

Paper presentations

Anna and Kishalay presented their recent papers on iPTF data. Both papers are very relevant for ZTF.

Anna searched the iPTF archive for fast transients that could be connected with GRB afterglows. She identified 45 candidates. Of those, two were GRB afterglows that had been found in dedicated follow-up observations to triggers from the Fermi satellite. Another object was a GRB afterglow discovered serendipitously. The remaining 37 candidates have red stellar counterparts in external catalogues. The photometric and spectroscopic properties of the counterparts identify those transients as strong flares from M dwarfs. One of the key messages of Anna's work is that we can use PanSTARRS and WISE data to filter flares from M dwarfs reliably!

You can find her paper at:

https://arxiv.org/abs/1712.00949

Kishalay presented his recent work on the hot and fast ultra-stripped Ic SN iPTF 14gqr in the halo of an interacting galaxy. The transient was discovered within 24 hours after the explosion. Rapid spectroscopic observations revealed HII, CIII and CIV in emission. Hence, that is the first stripped envelope SN with flash-spectroscopy. Even more remarkable is how rapidly 14gqr faded and its low peak luminosity. Modelling the bolometric light curve suggested a very low ejecta mass and explosion energy. That let Kishalay conclude that the progenitor of this explosion is different from those of regular stripped-envelope core-collapse supernovae. He proposed that the progenitor is a neutron-star binary system. Essential for his research was the high cadence and rapid spectroscopic observations.

• whitePSFKronDist.pdf: Star-galaxy separation - SG score for stars and galaxies as a function of Kron mag (provided by Adam Miller)

• whiteFeatures_log.pdf: Star-galaxy separation - Separation between stars and galaxies for different properties (provided by Adam Miller)

Minutes from 17/01/18

Attending

Ragnhild Lunnan (moderator, OKC), Mansi Kasliwal, Adam Miller, Christoffer Fremmling, Jacob Jencson, Kishalay De, and Matthew Graham (all Caltech), Cristina Barbarino, Francesco Taddia, Jesper Sollerman, Leonardo Tartaglia, and Suhail Dhawan (all OKC), Avishay Gal-Yam, Ofer Yaron, Steve Schulze, and Yi Yang (all WIS), Brad Cenko and Pradip Gatkine (UMD), and Melissa Graham (UW)

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New group member

Leonardo Tartaglia recently joined OKC. A warm welcome from the entire SN and relativistic transient WG!

Machine Learning

Adam presented the status of the star/galaxy separation project. The basis for the S/G separation will be the PanSTARRS DR1 and the COSMOS survey (training data set). In total 14 features (brightness and shape parameters) will be used to separate stars from galaxies. As can be seen from the attached plots, stars and galaxies are easy to distinguish over a wide magnitude range. IPAC will provide an S/G score for each transient and also the distance to the nearest known object in realtime. These information will be ingested by the GROWTH marshall and everybody will be able to set their own thresholds. Unfortunately, the S/G project is delayed because it takes more time to retrieve the relevant data from the PS1 catalogue via casjobs.

External collaborators

Avishay presented two MoUs to establish a collaboration with Giorgos Leloudas (DARK) on imaging polarimetry of CCSNe with the NOT and with a team led by Yi Yang (Weizmann) on imaging and spectropolarimetry of CCSNe with VLT/FORS2 and the Liverpool telescope. The contact person for both collaborations is Avishay. No major concerns were raised during the telecon. However, if you have questions or concerns, don't hesitate to contact Avishay.

ZTF

ZTF is currently offline for a final engineering run. Observations will resume on 30 January.

• whitePSFKronFlux.pdf: Star-galaxy separation - Comparison of PSF and Kron mag (provided by Adam Miller)

• whitePSFKronDist.pdf: Star-galaxy separation - SG score for stars and galaxies as a function of Kron magnitude

Minutes from 03/01/2018

Attending

Ragnhild Lunnan (moderator, OKC), Christoffer Fremmling, and Matthew Graham (all Caltech), Maayane Soumagnac, Steve Schulze, and Yi Yang (all WIS), and Anna Franckowiak (Berlin)

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ZTF

There have been a couple of failures, but they were not serious. ZTF will be down for a week starting from 9/10 January. The last week of January is supposed to be a SV run in survey mode. So, tune your eyes and sharpen your pencils to detect the first transients.

ZOGY subtractions and Real/Bogus

ZTF is on zooniverse, as announced in the previous ZTF Newsletter. You can help train the R/B machine-learning algorithm at https://www.zooniverse.org/projects/rswcit/ztf-rb-project.

Paper presentation

Ragnhild presented her latest Science paper on the fluorescent light echo in an SLSN. The result is spectacular! Check it out on our TWIKI page. Her lesson from (i)PTF "expect the unexpected".

Open positions

One open PhD and one open postdoc position in Stockholm (deadline 15 January)

http://www.su.se/english/about/working-at-su/jobs?rmlang=UK&rmpage=job&rmjob=4296

http://www.su.se/english/about/working-at-su/jobs?rmlang=UK&rmpage=job&rmjob=4355

Homework

Upload your recent papers/drafts to the TWIKI and use the opportunity to discuss them with everybody.

Schedule for the next weeks

Kishalay De will present his work on ultra-stripped CCSNe.

Minutes from 20/12/17

Ragnhild Lunnan (moderator, OKC), Mansi Kasliwal, Umaa Rebbapragada, Chris Cannella, Kishalay De, Christoffer Fremmling, and Matthew Graham (Caltech), Cristina Barbarino, Franceso Taddia, and Jesper Sollerman (OKC), Maayane Soumagnac, Steve Schulze, and Yi Yang (Weizmann), and Melissa Graham and Gwen (UW)

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GROWTH Marshall

Chris and Mansi gave a nice presentation about the GROWTH Marshall. The Marshall will be very similar to the iPTF Marshall, but it has some interesting add-ons: i) python interface to select targets; ii) organisation according to working groups, iii) automatically triggering follow-up facilities, e.g. SEDM, and iv) access control through admins. The Marshall is supposed to be rolled out ~15 January. You should receive an email to join.

Machine Learning

Umaa told us a few things from the Machine Learning group. Since last week, the differencing pipeline is in place. In the next days, there will be a call for volunteers to separate reals from artefacts in the test data. That will be your chance to teach a robot about the Universe. The ML group are also working on the streak detection and the star/galaxy separation. Maayane suggested that S/G classification should provide a probability so that everybody can apply their cuts. We came to the consensus that fostering more interaction between the ML and the science groups should be a priority to maximise our science return from ZTF.

SEDM white papers

There are four proposals. Team Sweden -- a census of SE-CCSN; Team Israel -- infant SNe (CCSN and Ia); Team Caltech -- flux-limited classification survey (PI: Shri) and relativistic transients (PI: Anna). Links to the first two programs are on the TWIKI. The first two programmes need about <10% of the available SEDM time each. We are looking forward to reading the drafts of the other programs! Fortunately and unfortunately, ranking the proposals for the SEDM TAC is a very tough job. We will not provide any ranking because each programme has a unique science case and needs a different amount of observing time.

The detailed instructions about the format and the upload are given at:

http://noir.caltech.edu/twiki_ptf/bin/viewauth/ZTF/SEDmWhitePaper

If in doubt whether you can still submit proposals on 1 January 2018, submit on 31 December. That allows you to have fewer things to do in 2018! :P

Next telecon

3 January 2018 (one week before the AAS).

Happy holidays and a Happy New Year to all of you!

Minutes from 6/12/17

Attending

Ragnhild Lunnan (moderator, OKC), Cristina Barbarino, Jesper Sollerman, and Francesco Taddia (all OKC), Anna Ho, Scott, Adam, Kishalay De, Christoffer Fremmling, and Jacob Jencson (Caltech), Avishay Gal-Yam, Ofer Yaron, Steve Schulze, and Yi Yang (all WIS), Valéry Brinnel and Jakob Nordin (Berlin), Brad Cenko (UMD), and Eric Bellm (UW)

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AMPEL - Alert Management, Photometry and Extraction of Lightcurves

Jakob gave an intriguing presentation on AMPEL. The aim of AMPEL is to provide a framework to design filters, quantify their usefulness, and give you the tools to reproduce the target selection over the whole ZTF duration. The presentation was attached to the email with the Minutes.

Berlin is preparing the documentation for the API and AMPEL. Code examples will be provided in ~2 weeks.

Fun fact: The icon on the front page indicates 'go' at pedestrian lights in the eastern part of Germany and the eastern part of Berlin.

SEDm

Francesco presented the proposal of the SESN programme. The proposal can be downloaded from https://www.dropbox.com/s/6tncwfr00ox86yn/whitepaperSEDmIbc_copy.pdf?dl=0.

Anna presented an idea to search for afterglows of relativistic transients. Important: Anna's paper on M dwarf flares is on astro-ph (http://adsabs.harvard.edu/abs/2017arXiv171200949H).

>External collaborations

Jesper: It would be nice to discuss proposals for external collaborations during the telecons.

Avishay told us that Weizmann is preparing a collaboration with three external groups:

>Project collaborations

i) Giorgos Leloudas (former WIS postdoc and now at Dark Cosmology Centre) is interested in imaging polarimetry of transients of interest with the NOT

ii) Collaborators of Yi Yang: Spectropolarimetry of infant CCSNe

Both projects add substantial scientific value to our group.

Ressource collaboration

i) Team around Antonio de Ugarte Postigo and Christina Thöne (IAA Granada)

They will provide a substantial amount of observing time with Spanish telescopes, including the 10.4-m GTC, for classifying and monitoring transients. They are interested in doing detailed follow-ups of a few selected SLSNe and SNe-IIn.

New job opportunities for a postdoc and a PhD student

http://www.su.se/english/about/working-at-su/jobs?rmlang=UK&rmpage=job&rmjob=4296

http://www.su.se/english/about/working-at-su/jobs?rmlang=UK&rmpage=job&rmjob=4355

Schedule for next week

-Prepare your draft for SEDm

-Presentation of the GROWTH Marshal

-Results from recent iPTF papers

-- SteveSchulze - 7 Dec 2017

Minutes from 29/11/17

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Christoffer Fremmling, and Kishalay De (all Caltech), Francesco Taddia and Jesper Sollerman (all OKC), Maayane Soumagnac, Adam Rubin, Avishay Gal-Yam, Ofer Yaron, Steve Schulze, and Yi Yang (all WIS), Virginia Cunningham, and Pradip Gatkine (UMD)

Items

SEDm

Three complementary proposals are planned:

-Magnitude-limited classification survey (led by Caltech)

-SNe Ib/c around maximum and pre-max Ib/c’s, if they are bright enough (led by OKC)

-Young SNe (led by Weizmann)

The relativistic transient group is discussing whether they should also prepare a draft.

Questions:

-Are any other proposals planned?

-Is there any interest in photometric follow-up of young SNe with SEDm?

Avishay: Colour information are also critical for young SNe. However, we first want to see how high the pressure at SEDm is.

Interesting facts:

-The limiting magnitude of the magnitude-limited survey is on the conservative. There is a niche for other programmes to target fainter transients.

-SEDm was not only improved on the instrumentation but also on the software side.

Follow-up facilities

-Avishay is exploring the option to use the 28’’ WISE telescope.

-Christoffer mentioned that GRBCam could be mounted at another telescope (Lick or Mt. Laguna observatories?). He will explore if this is feasible.

Status of P48

The camera was warmed up to remove contaminants. Observations resumed yesterday.

Conferences

-Mexico 11-15 December, 2017 (http://www.nucleares.unam.mx/dvu/)

-AAS 8-12 January, 2018 (https://aas.org/meetings/aas231)

Insider tip:

-37th Jerusalem Winter School on physics of astronomical transients 27 December – 5 January 2018 (http://www.as.huji.ac.il/content/35th-jerusalem-winter-school-theoretical-physics)

Schedule for next week

-Prepare your draft for SEDm

-Presentation of Ample (???)

-Presentation of the GROWTH Marshal (but on 13 December 2017)

-- SteveSchulze - 29 Nov 2017

Minutes from 22/11/17

Attending Christoffer Fremmling (Moderator), Mansi Kasliwal, Jacob Jencson, and Shri Kulkarni (Caltech), Maayane Soumagnac, Avishay Gal-Yam, Ofer Yaron, Steve Schulze, and Yi Yang (Weizmann), Francesco Taddia (OKC), and Virginia Cunningham, Pradip Gatkin (UMD)

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Science verification

If you have an accepted SV proposal, don’t forget to submit your queue files, to get your observations executed. Instructions were given in the last ZTF emails.

Perception of ZTF

Some external people have a misconception of ZTF. They assume that ZTF is private like PTF. We need to advocate more that ZTF has a large public component. If the misconception prevails, it could affect us, for instance, in getting proposals accepted.

Shri gave two talks at NOAO. NOAO liked the idea of the public flux-limited classification programme with SEDm. Mansi will emphasize the public component at the AAS. Avishay pointed out that we have time at the Wilhelm Herschel telescope to classify transients, which will also be made public.

Quality of ZTF images

Christoffer showed a few ZTF images. The general image quality is very good. Subtractions with PS1 reference images looked excellent. A few possible transients have been detected. Confirmations are needed before we can get spectra.

Follow-up facilities

Avishay has time at the WHT for two semesters (half a night per semester). The observing period has already started and Avishay is eager to trigger WHT on SV targets. Important: The time allocation can also be used with the NOT (in Spanish and Nordic time) and the ING. Avishay mentioned that Eran Ofek applied for LCOGT time. His team is also exploring the option to use two smaller telescopes at the WISE observatory for imaging.

Francesco said that OKC has 70 hours at the NOT and 30 hours at the TNG. They are also happy to trigger.

Christoffer has 4 nights at LCOGT for Ib/c SNe.

Caltech has additional 4 nights at LCOGT, to observe young SESNe and GRBs a few days after discovery.

Results from ESO and Gemini are pending.

SN imposter group

This project will be moved to the M31 group.

White paper

SEDm proposals should focus on spectroscopy. When you write your science case also detail which response time is needed. Although the SEDm deadline is on 1 January 2018, the time to work on the proposal is very limited. We need to have project drafts ready for the next 1-2 sessions.

Schedule for the next telecon(s)

-Mansi will present the GROWTH Marshall either next time or the week after. -SEDm. You will not get around thinking about your science case. :P

Minutes from 08/11/17

Minutes from 14/11/17

Ragnhild Lunnan (moderator, OKC), Anna Ho, Mansi Kasliwal, Scott Adams, Jacob Jencson and Shri Kulkarni (all Caltech), Cristina Barbarino, Ariel Goobar, Jesper Sollerman, Francesco Taddia (all OKC), Maayane Soumagnac, Adam Rubin, Avishay Gal-Yam, Steve Schulze, and Yi Yang (all WIS), and Virginia Cunningham, and Brad Cenko (all UMD).

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Cadence of the next telecons

Future telecons will be every Wednesday at 10 am PST.

SED Machine (SEDm)

IMPORTANT: The white-paper deadline was postponed to 2018 January 1.

Each Science group can submit multiple white papers. It is suggested that we do an internal ranking prior to submission. While you are designing your experiment, don’t forget to prepare a realistic estimate of the false positives. Shri pointed out that this is imperative for any successful proposal. Keep in mind that your false positives might be the targets for other projects. The sooner your project is added to the TWIKI, the sooner we can team up, explore synergies and discuss science beyond our imagination.

At the moment, we are exploring two different avenues for the white paper(s): young SNe (photometry and spectroscopy) and transients from a magnitude-limited survey (only spectroscopy for classification). A few projects were discussed.

-Francesco presented a program on nearby and bright Ib/c SNe. You can find the details on the TWIKI.

-Avishay presented a program for flash spectroscopy. Details will be added to the TWIKI. Next week we will also discuss SLSNe.

-Ariel spoke about young Ia’s.

Projects and student projects

Add more details on which data are needed for the success of your project and which people are involved. The TDE/AGN group has a very nice template for presenting projects.

-Avishay presented Noam Ganot’s PhD project on UV observations of young SNe-II. The idea for ZTF is to select very young SNe and observe them with Swift.

-Shri presented Anna’s project on afterglows to relativistic explosions.

-Jacob Jencson is working with Mansi on obscured SNe, selected by their large g-i and g-r colours. Critical for their study is the i'-band component of ZTF.

-Mattia Bulla is interested in reddened SNe to infer the location of dust lanes along the line of sight.

Animation how ZTF operates

Rahul Biswas prepared an animation to show the motion of ZTF’s field of view in different filters across the sky over a period of two consecutive nights. Check out the video at

https://www.youtube.com/watch?time_continue=88&v=Q5HR-SWx_-o

and the detailed description at

https://github.com/oskarkleincentre/cadence_demo_for_ztf/

Schedule for next week

-SEDm proposals

-Technical update from Caltech on ZTF. Christoffer might show his results on image subtraction

Attending

Ragnhild Lunnan (moderator, OKC), Anna Ho, Lin Yan, Mansi Kasliwal, Christoffer Fremmling, Kishalay De, and Shri Kulkarni (all Caltech), Cristina Barbarino, Anders Nyholm, and Francesco Taddia (all OKC), Maayane Soumagnac, Adam Rubin, Avishay Gal-Yam, Ofer Yaron, Steve Schulze, and Yi Yang (all WIS), Virginia Cunningham, and Brad Cenko (all UMD), and Jakob Nordin (Berlin)

Items

Cadence of the next telecons

At the beginning we should envision weekly telecons, to get to know to each other and make sure that we have the best possible start into ZTF. Next meeting might be at the same time. Ragnhild will send a doodle.

TWIKI

We should urgently add content. Suggestions are: "Introduce Yourself", "Follow-up programs", "Minutes", "Members", and "Projects".

Possible projects for SEDm

Shri: Flux-limited SN survey. Idea is to use SNe as probes to identify galaxies and check the completeness of local galaxy catalogues. Critical for follow-up observations of non-EM transients. Project is supposed to be time-limited. The idea is similar to Jakob's.

Christoffer: Using SEDm to secure spectra of IIb/Ibc SNe.

Brad: Rapid spectroscopy of relativistic transients.

Avishay: Flash spectroscopy.

Important: SEDm will not blindly observe targets. Observations will be awarded based on the science case.

Notes:

1. ) General GRB observations should not be the goal of SEDm. The GRB community is better geared up for it.
2. ) Same night observations should be possible.

Homework for next week

-Prepare a paragraph for your science case with SEDm and upload to the TWIKI. Which follow-up is needed? How much time is needed? etc. For the capabilities of SEDm see Ariel's email and the Nadia's paper on SEDm (https://arxiv.org/abs/1710.02917). CRITICAL: if no proposal is submitted by 1 December, we won't be able to use SEDm! SEDm can take spectra and images.

-Add PhD thesis (most important), postdoc and senior projects to the TWIKI.

-Add follow-up facilities to the TWIKI (which instrument, trigger criteria, boundary conditions, contact person)

-Go to the "Introduce Yourself" page and briefly introduce yourself, describe your skills and interests.

-- SteveSchulze - 08 Nov 2017