Scary Barbie: An Extremely Energetic, Long-duration Tidal Disruption Event Candidate without a Detected Host Galaxy at z = 0.995

Bhagya M. Subrayan; Dan Milisavljevic; Ryan Chornock; Raffaella Margutti; Kate D. Alexander; Vandana Ramakrishnan; Paul C. Duffell; Danielle A. Dickinson; Kyoung-Soo Lee; Dimitrios Giannios; Geoffery Lentner; Mark Linvill; Braden Garretson; Matthew J. Graham; Daniel Stern; Daniel Brethauer; Tien Duong; Wynn Jacobson-Galán; Natalie LeBaron; David Matthews; Huei Sears; Padma Venkatraman

doi:10.3847/2041-8213/accf1a

The Astrophysical Journal Letters (Jan 2023)

Scary Barbie: An Extremely Energetic, Long-duration Tidal Disruption Event Candidate without a Detected Host Galaxy at z = 0.995

Bhagya M. Subrayan,
Dan Milisavljevic,
Ryan Chornock,
Raffaella Margutti,
Kate D. Alexander,
Vandana Ramakrishnan,
Paul C. Duffell,
Danielle A. Dickinson,
Kyoung-Soo Lee,
Dimitrios Giannios,
Geoffery Lentner,
Mark Linvill,
Braden Garretson,
Matthew J. Graham,
Daniel Stern,
Daniel Brethauer,
Tien Duong,
Wynn Jacobson-Galán,
Natalie LeBaron,
David Matthews,
Huei Sears,
Padma Venkatraman

Affiliations

Bhagya M. Subrayan: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Dan Milisavljevic: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]; Integrative Data Science Initiative, Purdue University , West Lafayette, IN 47907, USA
Ryan Chornock: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
Raffaella Margutti: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
Kate D. Alexander: ORCiD; Department of Astronomy and Steward Observatory, University of Arizona , 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA
Vandana Ramakrishnan: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Paul C. Duffell: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Danielle A. Dickinson: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Kyoung-Soo Lee: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Dimitrios Giannios: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Geoffery Lentner: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Mark Linvill: Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Braden Garretson: ORCiD; Purdue University , Department of Physics and Astronomy, 525 Northwestern Avenue, West Lafayette, IN 47907, USA ; [email protected]
Matthew J. Graham: ORCiD; Division of Physics, Mathematics, and Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
Daniel Stern: ORCiD; Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
Daniel Brethauer: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
Tien Duong: Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
Wynn Jacobson-Galán: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
Natalie LeBaron: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
David Matthews: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA
Huei Sears: ORCiD; Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University , Evanston, IL 60202 USA; Department of Physics and Astronomy, Northwestern University , Evanston, IL 60208, USA
Padma Venkatraman: ORCiD; Department of Astronomy, University of California , Berkeley, CA 94720-3411, USA

DOI: https://doi.org/10.3847/2041-8213/accf1a
Journal volume & issue: Vol. 948, no. 2
p. L19

Abstract

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We report multiwavelength observations and characterization of the ultraluminous transient AT 2021lwx (ZTF20abrbeie; aka “Barbie”) identified in the alert stream of the Zwicky Transient Facility (ZTF) using a Recommender Engine For Intelligent Transient Tracking filter on the ANTARES alert broker. From a spectroscopically measured redshift of 0.995, we estimate a peak-observed pseudo-bolometric luminosity of log( ${L}_{\max }/[\mathrm{erg}\,{{\rm{s}}}^{-1}]$ ) = 45.7 from slowly fading ztf- g and ztf- r light curves spanning over 1000 observer-frame days. The host galaxy is not detected in archival Pan-STARRS observations ( g > 23.3 mag), implying a lower limit to the outburst amplitude of more than 5 mag relative to the quiescent host galaxy. Optical spectra exhibit strong emission lines with narrow cores from the H Balmer series and ultraviolet semi-forbidden lines of Si iii ] λ 1892, C iii ] λ 1909, and C ii ] λ 2325. Typical nebular lines in Active Galactic Nucleus (AGN) spectra from ions such as [O ii ] and [O iii ] are not detected. These spectral features, along with the smooth light curve that is unlike most AGN flaring activity and the luminosity that exceeds any observed or theorized supernova, lead us to conclude that AT 2021lwx is most likely an extreme tidal disruption event (TDE). Modeling of ZTF photometry with MOSFiT suggests that the TDE was between a ≈14 M _⊙ star and a supermassive black hole of mass M _BH ∼ 10 ^8 M _⊙ . Continued monitoring of the still-evolving light curve along with deep imaging of the field once AT 2021lwx has faded can test this hypothesis and potentially detect the host galaxy.

Published in The Astrophysical Journal Letters

ISSN: 2041-8205 (Print); 2041-8213 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/2041-8205

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