Difference: Projects (1 vs. 19)

• People + contributions: Chandra + HST+EP/FXT (Yuhan), XMM (Ryan), LRIS (Ryan)

• People + contributions: Late-time XMM + HST UV + LRIS (Zirui + Ryan); NuSTAR (Yuhan)

Systematic searches for off-nuclear TDEs using (non-ML) photometric properties

• Lead: Yuhan Yao (Berkeley)
• Other Participating:
• Other Resources:
• Abstract: real-time search for off-nuclear TDEs based on ZTF+LSST alerts, using photometric criteria developed as part of the off-nuclear rate paper.

• long-lasting TDE/Bowen Fluorescence flare in a pre-existing AGN

• EP detected X-ray flare at early times, featureless nuclear spectrum

• TDE with large offset from nucleus

• First off-nuclear TDE

TDE host sample paper

• People + contributions: Keck/LRIS spectra (Jean) + any other public data
• Basic idea: star-formation histories, apples-to-apples color/stellar population measurements in background sample, morphological study

Systematic searches for dwarf galaxy TDEs

• Lead: Jean Somalwar (Berkeley/Stanford)
• Other Participating: please let me know if you want to help, would love to have more people involved
• Other Resources: Chandra triggers
• Abstract: real-time search using (1) color-evolution based selection criteria, with minimal timescale cuts, to reject SNe while include anything blue and vaguely TDE-like and (2) a multi-stage dwarf galaxy selection with a CNN to identify z<0.03 dwarfs brighter than ~19.2 from DECam imaging and a separate hostless/faint galaxy component for cases where the CNN isn't reliable. Currently primarily using Lick to classify, but with proposals out for more classification resources. When/if Swift comes online, I will be aggressively triggering.

Archival search for faint/slow transients

• Lead: Jean Somalwar (Berkeley/Stanford)
• Other Participating:
• Other Resources:
• Abstract: this is not necessarily a TDE project, but maybe it will find some weird TDEs. I am running a ZUDS-like pipeline to search for optical transients in stacked ZTF data (currently 6months windows, shifting by 3months). I expect to find lots of AGN, plus maybe some IMBH TDEs if they are indeed slow and faint (and maybe some weird SNe, other unknown transients). The first paper will be on the LSST deep fields (currently running on COSMOS as an initial test), later I hope to do the ZTF+LSST overlap region.

Hero/AT2020afhd paper

• People + contributions: lead by Erica; Optical spectroscopy (LRIS, Kast, GHTS, DeVeny)

Ironman paper (not a ZTF paper)

Retrograde TDEs (in AGN) sample paper

• People + contributions: NGPS/LRIS spectra (Matthew)

Retrospective "photometric TDE" sample paper

• People + contributions: tdescore (Robert) + any spectra people want published of old TDEs

PAPERS IN PROGRESS

AT2023mfm (Jabba) paper

• Lead: Itai Sfaradi (Berkeley)
• Other contributing: Ryan Chornock (Berkeley)
• Other Resources: VLA, Kast+LRIS spectra
• Abstract: VLA radio detection of off-nuclear TDE, light curve + spectra to say this is a TDE

Brutus UV+optical paper

• Lead: Erica Hammerstein (Berkeley)
• Other contributing: Ryan Chornock (Berkeley), Jean Somalwar (Berkeley)
• Other Resources: HST UV spectrum (epoch 1), Kast + LRIS optical spectra, Chandra DDT observations
• Abstract: First pre-peak UV spectrum of a TDE + light curves and optical spectral evolution

Off-nuclear TDE rates paper

• Lead: Robert Stein (JSI) + Yuhan Yao (Berkeley)
• Other contributing: Ryan Chornock (Berkeley)
• Other Resources:
• Abstract: constraints on rates of off-nuclear TDE from a retrospective analysis

AT2022dbl paper

• Lead: Sunny Guo (formerly Berkeley)
• Other contributing: Ryan Chornock (Berkeley)
• Other Resources: Kast+LRIS spectral sequence
• Abstract: Comparing the two flares in 2022 and 2024 from this source

Brutus JWST paper

• Lead: Jean Somalwar (Berkeley)
• Other contributing:
• Other Resources: JWST DDT IFU observations
• Abstract: Host galaxy focus for Brutus

Ironman paper

• Lead: Matthew Graham (Caltech)
• Other contributing:
• Other Resources: Keck follow-up obs
• Abstract: ENT with a large outburst

Brutus NIR paper

• Lead: Xander Hall (CMU) + Robert Stein (UMD)
• Other contributing:
• Other Resources: Gemini+NIRES NIR spectra, Wendelstein NIR light curves
• Abstract: NIR echo from Brutus

FUTURE PAPERS

Oddish/TDE2026hir paper

• People + contributions: VLA radio (Nayana), HST UV (Yuhan), LRIS spectra (Ryan)

Late-time TDE2025abcr (Fortinbras) paper

• People + contributions: Chandra + HST (Yuhan), XMM (Ryan), LRIS (Ryan)

Late-time AT2024tvd (Cordelia) paper

• People + contributions: Late-time XMM + HST UV + LRIS (Zirui + Ryan)

GRAD STUDENT/THESIS PROJECTS

Spectral Evolution of Infant TDEs (?)

• Lead: Jon Carney (UNC)
• Others Participating: Igor Andreoni (UNC)

• Other Resources: SOAR follow-up spectra
• Abstract: Spectral evolution of infant TDEs classified through SOAR program

ZTF+Rubin Late-time Plateaus

• Lead: Sara Starecheski (UMD)
• Others Participating: Suvi Gezari (UMD)

• Other Resources:
• Abstract: Looking for late-time plateaus in Rubin data for old ZTF TDEs

Rubin High-z TDEs (Collaborator project)

• Lead: Mitchell Karmen (JHU)
• Others Participating: Suvi Gezari (UMD)
• Thesis? Yes. Expected completion date: TBD
• Other Resources:
• Abstract: Looking for high-z TDEs in JWST COSMOS-Web, Rubin, and Roman

LONG-TERM PROJECTS

• Other Resources:

A closer look at TDE hosts

• Lead: Erica Hammerstein (UMD)
• Others Participating: Brad Cenko (GSFC), Suvi Gezari (Stsci)
• Thesis? Yes. Expected completion date: TBD
• Abstract: This study will build on Hammerstein et al. (2021) but will include higher resolution imaging to better understand the structure of TDE hosts on scales closer to the nucleus of the host. Low surface brightness features can also be found with better imaging than what SDSS provides.

A broad look at TDEs in the UV

• Lead: Erica Hammerstein (UMD)
• Others Participating: Brad Cenko (GSFC), Suvi Gezari (Stsci)
• Thesis? Yes. Expected completion date: TBD
• Abstract: The project is in the very early stages. We are interested in looking at the UV spectra of TDEs to further understand UV properties and potential connections to optical classifications. Potential for UV imaging component as well.

XMM follow-up of TDEs in ZTF: Building a Legacy X-ray Sample

• Point of contact: Suvi Gezari (STScI)
• Note: This is an approved Cycle 20 program to follow-up 6 ZTF TDEs with two epochs of X-ray imaging with XMM. This builds upon our XMM program from Cycle 18 for ZTF-I TDEs.
• Thesis? this could support a graduate student working with me at STScI
• Abstract: The importance of this program will be to probe the evolution of the X-ray emission, and use the spectral properties to distinguish between models (reprocessing vs. circularization delay). This project should be complementary to the eROSITA selected TDE sample.

Luminosity function, mass function, and black hole occupation fraction

• Lead: Sjoert van Velzen (Leiden)
• Others Participating: all TDE members
• Thesis? Possible if Leiden student joins (Expected completion date: 2025)
• Abstract: Goal is to understand the origin of black hole via a measurement of the occupation fraction with forward modelling (see van Velzen 2018). This requires a complete sample of TDEs and a good understand of the survey selection effects. The LF measurements need to be done with a spectroscopic sample, while the occupation fraction measurement is possible with a photometrically selected sample.
• Required data products: forced photometry for selection, complete spectro follow-up for m<19 (SEDM); u-band for a subset

Radio follow-up of classical TDEs with the VLA

• Point of contact: Sjoert van Velzen
• Note: This is project will happen outside of this collaboration (the VLA core team is: Kate Alexander, Sjoert van Velzen, James Miller-Jones). But these radio resources can be used for ZTF-papers from this group
• Thesis? no
• Abstract: What is the orign of radio emission from TDEs? We have a Large VLA program (300 hour) to find out.
• Required data products: Spectroscopically confirmed TDEs

IR follow-up of TDEs: dust echoes and the search for free-free signature

• Point of contact: Erik Kool (Stockholmn) and Sjoert van Velzen (Leiden)
• Note: just like the VLA observations, this is project will mainly happen outside of the ZTF collaboration. But it will be good to be aware these observations are happening. The core team is: Erik Kool, Sjoert van Velzen, Thomas Reynolds, and Seppo Mattila.
• Thesis? no
• Abstract: Explore the reddest end of the TDE spectrum with follow-up yJHK observations. All theorist seem to predict we should see a deviation from the RL tail due to free-free emission, so we will look for this. Even more important is the search for dust echoes with these ground-band observations. If this is possible, we can trigger JWST (proposal submitted). We have NOT time for about 6 TDEs per year.

• Abstract: Compare ZTF matchfiles with known catalogs of AGN, galaxies, blazars, etc. to identify sources showing significant (unexpected) variability for followup * Required data products: Matchfiles/light curves, extragalactic source catalogs

An X-ray view of eROSITA/ZTF TDEs

• Lead: Yuhan Yao (Caltech)
• Others Participating: Shri Kulkarni (Caltech), Marat Gilfanov (MPIA), Suvi Gezari (Stsci)
• Thesis? Yes. Expected completion date: July 2023
• Abstract: This project is in the early stage. The main goal is to characterize the population of eROSITA-bright and ZTF-faint TDEs.

• Required data products: Transient alerts, star/galaxy catalog, stochastic variability flag
  
  

Detecting Isolated Black Hole Candidates via Microlensing

• Lead: Michael Medford (LLNL)
• Others Participating: Peter Nugent (LLNL)
• Thesis? Yes. Expected completion date: May 2021
• Abstract: Multi-band lightcurves from the bulk lightcurves will be analyzed and fit to microlensing models that have high likelihood to be isolated black hole candidates. This work will involve developing and applying innovative approaches for measuring microlensing likelihoods at scale to enable a timely search across ZTF's massive dataset.
• Required data products: Public/Partnership bulk lightcurves, i-band survey data, transient alerts

Looking from EM signatures from LIGO events in AGN disks

• Lead: Matthew Graham (Caltech)
• Other Participating:
• Abstract: Look for alerts from AGN coincident with LIGO triggers according to the mechanism proposed by McKernan et al. (2019)
• Required data products: Transient alerts, external AGN catalogs

GROUP PROJECTS

Systematic searches for extreme variable AGN

• Lead: Matthew Graham (Caltech)
• Other Participating:
• Abstract: Compare ZTF matchfiles with known catalogs of AGN, galaxies, blazars, etc. to identify sources showing significant (unexpected) variability for followup * Required data products: Matchfiles/light curves, extragalactic source catalogs

THESIS PROJECTS

POSTDOC PROJECTS

• Thesis? Yes. Expected completion date: December 2018

Search and Follow-up of Changing-Look AGNs

• Lead: Sara Frederick (UMd)
• Others Participating: Suvi Gezari (UMd)
• Thesis? Yes. Expected completion date: Summer 2020
• Abstract: CLAGNs will be flagged from the ZTF transient alert stream from known Type 2 AGN that demonstrate a large amplitude of variability. Once a CLAGN is identified from a classification spectrum, we will trigger follow-up optical spectroscopy, as well as multiwavelength (X-ray, UV, optical) monitoring. The goal of the program is to determine the physical mechanism driving the "changing look" for a sample of about 3 CLAGNs per year.
• Required data products: Transient alerts, Type 2 AGN catalogs, classification spectroscopy, Swift TOO imaging

Search for Offset AGN as Recoiling SMBH Candidates

• Lead: Charlotte Ward (UMd)
• Others Participating: Suvi Gezari (UMd)
• Thesis? Yes. Expected completion date: Summer 2022
• Abstract: Offset AGN will be flagged from the ZTF transient alert stream from stochastically variable sources that have offsets from their host galaxy nucleus. Candidate offset AGN will be followed up with spectroscopy and high spatial resolution imaging.
• Required data products: Transient alerts, star/galaxy catalog, stochastic variability flag

Predictive monitoring of AGN

• Lead: Matthew Graham (Caltech)
• Others Participating: Yutaro Tachibana (Tokyo Tech)
• Thesis? December 2018
• Abstract: Generative models (HMM, RNN, GPR) will be trained on a subset of known quasars and used to predict variability. This will be compared to observed variability and unexpected behavior will trigger more detailed monitoring (spectroscopic, multiwavelength) to track changes. The expected number of unusual sources at any time is ~25.
• Required data products: Nightly aperture photometry for the set of quasars with predictive models.

Title1

• Lead: Name (Institution)
• Others Participating: Names
• Thesis? If yes, expected completion date:
• Abstract:
• Required data products:

Title2

• Lead: Name (Institution)
• Others Participating: Names
• Thesis? If yes, expected completion date:
• Abstract:
• Required data products:

-- SuviGezari - 20 Oct 2017