CaltechAUTHORS
Published February 20, 2019 | Version Published + Accepted Version
Journal Article Open

The First Tidal Disruption Flare in ZTF: From Photometric Selection to Multi-wavelength Characterization

Creators

  • 1. ROR icon University of Maryland, College Park
  • 2. ROR icon New York University
  • 3. ROR icon Goddard Space Flight Center
  • 4. ROR icon Curtin University
  • 5. ROR icon University of Oxford
  • 6. ROR icon California Institute of Technology
  • 7. ROR icon University of Washington
  • 8. ROR icon Weizmann Institute of Science
  • 9. ROR icon Stockholm University
  • 10. ROR icon Deutsches Elektronen-Synchrotron DESY
  • 11. ROR icon Humboldt-Universität zu Berlin
  • 12. ROR icon University of California, Santa Barbara
  • 13. ROR icon Infrared Processing and Analysis Center
  • 14. ROR icon Northwestern University
  • 15. ROR icon Adler Planetarium
  • 16. ROR icon University of Clermont Auvergne

Abstract

We present Zwicky Transient Facility (ZTF) observations of the tidal disruption flare AT2018zr/PS18kh reported by Holoien et al. and detected during ZTF commissioning. The ZTF light curve of the tidal disruption event (TDE) samples the rise-to-peak exceptionally well, with 50 days of g- and r-band detections before the time of maximum light. We also present our multi-wavelength follow-up observations, including the detection of a thermal (kT ≈ 100 eV) X-ray source that is two orders of magnitude fainter than the contemporaneous optical/UV blackbody luminosity, and a stringent upper limit to the radio emission. We use observations of 128 known active galactic nuclei (AGNs) to assess the quality of the ZTF astrometry, finding a median host-flare distance of 0farcs2 for genuine nuclear flares. Using ZTF observations of variability from known AGNs and supernovae we show how these sources can be separated from TDEs. A combination of light-curve shape, color, and location in the host galaxy can be used to select a clean TDE sample from multi-band optical surveys such as ZTF or the Large Synoptic Survey Telescope.

Additional Information

© 2019 The American Astronomical Society. Received 2018 September 7; revised 2018 December 21; accepted 2019 January 5; published 2019 February 25. We thank the referee for the useful comments. This work is based on observations obtained with the Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. Major funding has been provided by the U.S National Science Foundation under grant No. AST-1440341 and by the ZTF partner institutions: the California Institute of Technology, the Oskar Klein Centre, the Weizmann Institute of Science, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron, the University of Wisconsin-Milwaukee, and the TANGO Program of the University System of Taiwan. We thank the National Radio Astronomy Observatory (NRAO) staff for the rapid scheduling of the VLA observations. NRAO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. We thank the staff of the Mullard Radio Astronomy Observatory for their assistance in the operation of AMI. We acknowledge the use of public data from the Swift data archive. This research made use of Astropy, a community-developed core Python package for Astronomy (The Astropy Collaboration et al. 2018). S. Gezari is supported in part by NSF CAREER grant 1454816 and NSF AAG grant 1616566. M. M. Kasliwal acknowledges support by the GROWTH (Global Relay of Observatories Watching Transients Happen) project funded by the National Science Foundation PIRE (Partnership in International Research and Education) program under Grant No 1545949. N.R. acknowledges the support of a Joint Space-Science Institute prize postdoctoral fellowship. J.C.A.M.-J. is supported by an Australian Research Council Future Fellowship (FT140101082). This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 759194—USNAC). Software: Astropy (The Astropy Collaboration et al. 2018), CASA (McMullin et al. 2007), HEAsoft (Arnaud 1996), SAS (Gabriel et al. 2004), FSPS (Conroy et al. 2009; Conroy & Gunn 2010) with Python binding from Foreman-Mackey et al. 2014).

Attached Files

Published - van_Velzen_2019_ApJ_872_198.pdf

Accepted Version - 1809.02608.pdf

Files

1809.02608.pdf

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Additional details

Identifiers

Eprint ID
93218
Resolver ID
CaltechAUTHORS:20190225-095722804

Related works

Describes
https://arxiv.org/abs/1809.02608 (URL)

Funding

NSF
AST-1440341
Caltech
Oskar Klein Centre
Weizmann Institute of Science
University of Maryland
University of Washington
Deutsches Elektronen-Synchrotron
University of Wisconsin-Milwaukee
University System of Taiwan
Associated Universities, Inc.
NSF
AST-1454816
NSF
AST-1616566
NSF
OISE-1545949
Joint Space-Science Institute
Australian Research Council
FT140101082
European Research Council (ERC)
759194

Dates

Created
2019-02-25
Created from EPrint's datestamp field
Updated
2021-11-16
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility, Astronomy Department, Division of Geological and Planetary Sciences (GPS)