TY - JOUR
T1 - Real-time discovery of AT2020xnd
T2 - a fast, luminous ultraviolet transient with minimal radioactive ejecta
AU - Perley, Daniel A.
AU - Ho, Anna Y. Q.
AU - Yao, Yuhan
AU - Fremling, Christoffer
AU - Anderson, Joseph P.
AU - Schulze, Steve
AU - Kumar, Harsh
AU - Anupama, G. C.
AU - Barway, Sudhanshu
AU - Bellm, Eric C.
AU - Bhalerao, Varun
AU - Chen, Ting-Wan
AU - Duev, Dmitry A.
AU - Galbany, Lluís
AU - Graham, Matthew J.
AU - Gromadzki, Mariusz
AU - Gutiérrez, Claudia P.
AU - Ihanec, Nada
AU - Inserra, Cosimo
AU - Kasliwal, Mansi M.
AU - Kool, Erik C.
AU - Kulkarni, S. R.
AU - Laher, Russ R.
AU - Masci, Frank J.
AU - Neill, James D.
AU - Nicholl, Matt
AU - Pursiainen, Miika
AU - van Roestel, Joannes
AU - Sharma, Yashvi
AU - Sollerman, Jesper
AU - Walters, Richard
AU - Wiseman, Philip
N1 - Publisher Copyright:
© 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2021/12
Y1 - 2021/12
N2 - The many unusual properties of the enigmatic AT2018cow suggested that at least some subset of the empirical class of fast blue optical transients (FBOTs) represents a genuinely new astrophysical phenomenon. Unfortunately, the intrinsic rarity and fleeting nature of these events have made it difficult to identify additional examples early enough to acquire the observations necessary to constrain theoretical models. We present here the Zwicky Transient Facility discovery of AT2020xnd (ZTF20acigmel, the 'Camel') at z = 0.243, the first unambiguous AT2018cow analogue to be found and confirmed in real time. AT2018cow and AT2020xnd share all key observational properties: a fast optical rise, sustained high photospheric temperature, absence of a second peak attributable to ejection of a radioactively heated stellar envelope, extremely luminous radio, millimetre, and X-ray emission, and a dwarf-galaxy host. This supports the argument that AT2018cow-like events represent a distinct phenomenon from slower-evolving radio-quiet supernovae, likely requiring a different progenitor or a different central engine. The sample properties of the four known members of this class to date disfavour tidal disruption models but are consistent with the alternative model of an accretion powered jet following the direct collapse of a massive star to a black hole. Contextual filtering of alert streams combined with rapid photometric verification using multiband imaging provides an efficient way to identify future members of this class, even at high redshift....
AB - The many unusual properties of the enigmatic AT2018cow suggested that at least some subset of the empirical class of fast blue optical transients (FBOTs) represents a genuinely new astrophysical phenomenon. Unfortunately, the intrinsic rarity and fleeting nature of these events have made it difficult to identify additional examples early enough to acquire the observations necessary to constrain theoretical models. We present here the Zwicky Transient Facility discovery of AT2020xnd (ZTF20acigmel, the 'Camel') at z = 0.243, the first unambiguous AT2018cow analogue to be found and confirmed in real time. AT2018cow and AT2020xnd share all key observational properties: a fast optical rise, sustained high photospheric temperature, absence of a second peak attributable to ejection of a radioactively heated stellar envelope, extremely luminous radio, millimetre, and X-ray emission, and a dwarf-galaxy host. This supports the argument that AT2018cow-like events represent a distinct phenomenon from slower-evolving radio-quiet supernovae, likely requiring a different progenitor or a different central engine. The sample properties of the four known members of this class to date disfavour tidal disruption models but are consistent with the alternative model of an accretion powered jet following the direct collapse of a massive star to a black hole. Contextual filtering of alert streams combined with rapid photometric verification using multiband imaging provides an efficient way to identify future members of this class, even at high redshift....
KW - supernovae: individual: AT2020xnd
KW - transients: supernovae
UR - http://www.scopus.com/inward/record.url?scp=85118994657&partnerID=8YFLogxK
UR - https://arxiv.org/pdf/2103.01968.pdf
U2 - 10.1093/mnras/stab2785
DO - 10.1093/mnras/stab2785
M3 - Article
SN - 0035-8711
VL - 508
SP - 5138
EP - 5147
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -