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author Kool, E.C.
Reynolds, T.M.
Mattila, S.
Kankare, E.
Pérez-Torres, M.A.
Efstathiou, A.
Ryder, S.
Romero-Cañizales, C.
Lu, W.
Heikkilä, T.
Anderson, Gemma
Berton, M.
Bright, J.
Cannizzaro, G.
Eappachen, D.
Fraser, M.
Gromadzki, M.
Jonker, P.G.
Kuncarayakti, H.
Lundqvist, P.
Maeda, K.
Mcdermid, R.M.
Medling, A.M.
Moran, S.
Reguitti, A.
Shahbandeh, M.
Tsygankov, S.
Lebouteiller, V.
Wevers, T.
author_facet Kool, E.C.
Reynolds, T.M.
Mattila, S.
Kankare, E.
Pérez-Torres, M.A.
Efstathiou, A.
Ryder, S.
Romero-Cañizales, C.
Lu, W.
Heikkilä, T.
Anderson, Gemma
Berton, M.
Bright, J.
Cannizzaro, G.
Eappachen, D.
Fraser, M.
Gromadzki, M.
Jonker, P.G.
Kuncarayakti, H.
Lundqvist, P.
Maeda, K.
Mcdermid, R.M.
Medling, A.M.
Moran, S.
Reguitti, A.
Shahbandeh, M.
Tsygankov, S.
Lebouteiller, V.
Wevers, T.
author_sort Kool, E.C.
building Curtin Institutional Repository
collection Online Access
description We present the discovery with Keck of the extremely infrared (IR) luminous transient AT 2017gbl, coincident with the Northern nucleus of the luminous infrared galaxy (LIRG) IRAS 23436+5257. Our extensive multiwavelength follow-up spans ∼900 d, including photometry and spectroscopy in the optical and IR, and (very long baseline interferometry) radio and X-ray observations. Radiative transfer modelling of the host galaxy spectral energy distribution and long-term pre-outburst variability in the mid-IR indicate the presence of a hitherto undetected dust obscured active galactic nucleus (AGN). The optical and near-IR spectra show broad ∼2000 km s-1 hydrogen, He i, and O i emission features that decrease in flux over time. Radio imaging shows a fast evolving compact source of synchrotron emission spatially coincident with AT 2017gbl. We infer a lower limit for the radiated energy of 7.3 × 1050 erg from the IR photometry. An extremely energetic supernova would satisfy this budget, but is ruled out by the radio counterpart evolution. Instead, we propose AT 2017gbl is related to an accretion event by the central supermassive black hole, where the spectral signatures originate in the AGN broad line region and the IR photometry is consistent with re-radiation by polar dust. Given the fast evolution of AT 2017gbl, we deem a tidal disruption event (TDE) of a star a more plausible scenario than a dramatic change in the AGN accretion rate. This makes AT 2017gbl the third TDE candidate to be hosted by a LIRG, in contrast to the so far considered TDE population discovered at optical wavelengths and hosted preferably by post-starburst galaxies.
first_indexed 2025-11-14T11:34:06Z
format Journal Article
id curtin-20.500.11937-90304
institution Curtin University Malaysia
institution_category Local University
language English
last_indexed 2025-11-14T11:34:06Z
publishDate 2020
publisher OXFORD UNIV PRESS
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-903042023-02-10T02:56:41Z AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy Kool, E.C. Reynolds, T.M. Mattila, S. Kankare, E. Pérez-Torres, M.A. Efstathiou, A. Ryder, S. Romero-Cañizales, C. Lu, W. Heikkilä, T. Anderson, Gemma Berton, M. Bright, J. Cannizzaro, G. Eappachen, D. Fraser, M. Gromadzki, M. Jonker, P.G. Kuncarayakti, H. Lundqvist, P. Maeda, K. Mcdermid, R.M. Medling, A.M. Moran, S. Reguitti, A. Shahbandeh, M. Tsygankov, S. Lebouteiller, V. Wevers, T. Science & Technology Physical Sciences Astronomy & Astrophysics accretion, accretion discs black hole physics galaxies: active galaxies: nuclei transients: tidal disruption events ACTIVE GALACTIC NUCLEI TIDAL DISRUPTION FLARE EMISSION-LINE REGION MOLECULAR-HYDROGEN FE-II RADIO-EMISSION STAR-FORMATION DATA RELEASE BLACK-HOLES SN 1988Z We present the discovery with Keck of the extremely infrared (IR) luminous transient AT 2017gbl, coincident with the Northern nucleus of the luminous infrared galaxy (LIRG) IRAS 23436+5257. Our extensive multiwavelength follow-up spans ∼900 d, including photometry and spectroscopy in the optical and IR, and (very long baseline interferometry) radio and X-ray observations. Radiative transfer modelling of the host galaxy spectral energy distribution and long-term pre-outburst variability in the mid-IR indicate the presence of a hitherto undetected dust obscured active galactic nucleus (AGN). The optical and near-IR spectra show broad ∼2000 km s-1 hydrogen, He i, and O i emission features that decrease in flux over time. Radio imaging shows a fast evolving compact source of synchrotron emission spatially coincident with AT 2017gbl. We infer a lower limit for the radiated energy of 7.3 × 1050 erg from the IR photometry. An extremely energetic supernova would satisfy this budget, but is ruled out by the radio counterpart evolution. Instead, we propose AT 2017gbl is related to an accretion event by the central supermassive black hole, where the spectral signatures originate in the AGN broad line region and the IR photometry is consistent with re-radiation by polar dust. Given the fast evolution of AT 2017gbl, we deem a tidal disruption event (TDE) of a star a more plausible scenario than a dramatic change in the AGN accretion rate. This makes AT 2017gbl the third TDE candidate to be hosted by a LIRG, in contrast to the so far considered TDE population discovered at optical wavelengths and hosted preferably by post-starburst galaxies. 2020 Journal Article http://hdl.handle.net/20.500.11937/90304 10.1093/mnras/staa2351 English http://purl.org/au-research/grants/arc/DE180100346 http://purl.org/au-research/grants/arc/DP200102471 http://purl.org/au-research/grants/arc/FT150100333 OXFORD UNIV PRESS fulltext
spellingShingle Science & Technology
Physical Sciences
Astronomy & Astrophysics
accretion, accretion discs
black hole physics
galaxies: active
galaxies: nuclei
transients: tidal disruption events
ACTIVE GALACTIC NUCLEI
TIDAL DISRUPTION FLARE
EMISSION-LINE REGION
MOLECULAR-HYDROGEN
FE-II
RADIO-EMISSION
STAR-FORMATION
DATA RELEASE
BLACK-HOLES
SN 1988Z
Kool, E.C.
Reynolds, T.M.
Mattila, S.
Kankare, E.
Pérez-Torres, M.A.
Efstathiou, A.
Ryder, S.
Romero-Cañizales, C.
Lu, W.
Heikkilä, T.
Anderson, Gemma
Berton, M.
Bright, J.
Cannizzaro, G.
Eappachen, D.
Fraser, M.
Gromadzki, M.
Jonker, P.G.
Kuncarayakti, H.
Lundqvist, P.
Maeda, K.
Mcdermid, R.M.
Medling, A.M.
Moran, S.
Reguitti, A.
Shahbandeh, M.
Tsygankov, S.
Lebouteiller, V.
Wevers, T.
AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy
title AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy
title_full AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy
title_fullStr AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy
title_full_unstemmed AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy
title_short AT 2017gbl: A dust obscured TDE candidate in a luminous infrared galaxy
title_sort at 2017gbl: a dust obscured tde candidate in a luminous infrared galaxy
topic Science & Technology
Physical Sciences
Astronomy & Astrophysics
accretion, accretion discs
black hole physics
galaxies: active
galaxies: nuclei
transients: tidal disruption events
ACTIVE GALACTIC NUCLEI
TIDAL DISRUPTION FLARE
EMISSION-LINE REGION
MOLECULAR-HYDROGEN
FE-II
RADIO-EMISSION
STAR-FORMATION
DATA RELEASE
BLACK-HOLES
SN 1988Z
url http://purl.org/au-research/grants/arc/DE180100346
http://purl.org/au-research/grants/arc/DE180100346
http://purl.org/au-research/grants/arc/DE180100346
http://hdl.handle.net/20.500.11937/90304