ZTF Cosmology with SNe and gravitational lensing Working Group

This is the Wiki page for the ZTF Working Group on cosmology with SNe and gravitational lensing.

Some material may be found on the previous SNeIa page.

Contact information:

coordinators: Suhail Dhawan, OKC (Coordinator), Jakob Nordin, HU (Deputy Coordinator)

mailing list: ztfia@lists.astro.caltech.edu sign up here

slack organization: ztfia.slack.com [contact Uli to get an invitation]

meeting time: Alternating between Wednesdays 14:00 CET and Wednesdays 17:00 CET

Minutes:

Telecon minutes can be found here.

October 2018 spectroscopic campaign:

This will run for approximately 20 days with the combined goals of investigating how deep an effective ZTF SNIa search can go and what spectroscopic resources this would require/warrant.

• Current status and motivation
• Instantaneus cosmologist task
• Spectroscopic resources

Cosmology tasklist Summer 2018

The ZTF camera is great. The raw calibration is better than expected. SEDM works. We find roughly the right order of transients. ZTF could really do ground-breaking cosmology.

But, this requires 2000 (4000+) spectroscopically confirmed and calibrated SNe Ia. Need to get the program running and convince the collaboratoin that its cool. No excuses.

• Draft outline group for ZTF cosmology project. Ariel, Mickael, Jakob, Uli, Peter, …
• Show observed rate agrees with simulations. Uli
• Isolate subset of SNe with minimal/flat host contribution. Script to download PS photometry at coordinate, fit the background with some metric (plane?) and record outcome. Combined with visual confirmation? Ariel
• Isolate subset of SNe with spectroscopic host redshifts. To what extend can we trust marshal notes? Probably at least want to complement with something slightly more complex. Match with SDSS and NED, calculate confusion metric. CLU matches probably only available throuch Caltech. OKC – Lauras code?
• Maintain our list of typed SNe Ia, routines for classification (SNID) and subclassification. Are there cases that are ambigous? Semeli/Uli writeup of current.
• Fit floating SNIa lightcurves to everything in AMPEL - did we miss anything looking like a Ia? JN
• Trigger instructions for LCO. They have a nice visual tool, but we probably need a script to gather the necessary information. Done frequently by the SN group so they might already have this.
• TNS submission manual. For single entries there is a convenient web form, Christoffer also has a python script. Probably need to gather some information like what candidates do we want to / should we submit and eg what acknowledgments are used.
• Figure out how to use the SNCOSMO data (include other templates?, peak fit?, floating offset? upper limits?). I am sure there are cases where the fit is not representative, typically when post-peak data is missing. Mickael
• AGN rejection in AMPEL. Core distance, catalog matching and variability. Previous variability rejection in AMPEL. Through 30day history and/or PTF. Peter, Nadia, Matteo
• Maintain updated hubble diagram with diagnostics. Blinding!?! Flag SNe with offset. Ampel
• SNIFS trigger script: For a given SN, incorporate finding chart into the SNIFS observing database. Mickael.
• SNIFS training and shifting. We should be ~8 shifters to make this a trivial task (~ a few hoursslac each month) Uli, Mickael, Daniel, Mattia, Jakob, Suhail
• Immediate SNIFS target selection (for monday, so, today).
• ePESSTO. Ampel slack note for potential targets (Uli/Jakob).
• SN cosmoloy program coordination (RCF, ePESSTO, LCO, SNIFS program combination and priority, monitoring). When should what be triggered? Successfull?
• Web DB interface to coordinate observation. Peter, Uli
• Organize Marshal Scanning: as partners of ZTF, to verify our filters and/or to make candidate selections. This is also an excellent way to interact with the SN group,= and work eg on early SNIa.
• I-band fringing. We will be expected to be able to say how well the I-band works before getting more time. Regenerative networks. Peter / Mickael
• Flatfield (multiple subcomoponents). Matteo
• RFC comparison vs HU clean - would we have missed anything, found anything extra? Matteo / JN
• AMPEL/Marshal interaction: Implement that candidates saved in a marshal program is not submitted again. JN

SWG task chairs: So how much of this gets done?

These are intended to distribute live survey work, and each require 10-20% time commitment. In case this is exceeded a task is to be split, or distribute work to the SWG (could be scanning/shifting). The first step will be to determine the tools and procedures that should be used.

• Candidate selection. (PI: Uli) Are candidates selected as expected? Ingestion of external transients. Scanning evaluation/comparison/organization.
• Ranking. (PI: Ariel) Is the current transient ranking reasonable? What can be done to improve this?
• Follow-up trigger. (PI: Mickael) Interface to eg NOT, SNIFS, LCO, SEDM. Tools for telescope availability and finding charts.
• Telescope shifting. (PI: Daniel -Berlin-) SNIFS + possibly other facilities require shifting
• Data evaluation. (PI: Suhail) Do we have the spectra? Is the quality sufficient? What is the (sub)type?
• Photometry review. (PI: Jakob, C-I on commissioning: Matteo ) What is the current lightcurve quality, what are the limiting factors?
• Program progress. (PI: Uli) Are we on track for publication? Long term follow-up need and proposals?

Projects:

• AMPEL T2/science modules (Valéry)
• Search for lensed SNe (Danny)
• Lightcurve Simulations (Uli)
• Bulk flow and shear prediction (Uli)
• Inspection of lightcurves on marshal (Uli)

Members:

OKC

• Rahul Biswas
• Mattia Bulla
• Suhail Dhawan
• Uli Feindt
• Ariel Goobar
• Laura Hangard
• Seméli Papadogiannakis

HU/DESY

• Valéry Brinnel
• Matteo Giomi
• Jakob Nordin
• Marek Kowalski

In2p3

• Mickael Rigault

Berkeley

• Danny Goldstein
• Peter Nugent