On the recent discovery claim of a new $z>7$ quasar [GA]

http://arxiv.org/abs/2304.05162


Koptelova et al. 2022 (K22) recently claimed a new quasar discovery at $z=7.46$. After careful consideration of the publicly-available data underlying K22’s claim, we find that the observations were contaminated by a moving Solar System object, likely a main-belt asteroid. In the absence of the contaminated photometry, there is no evidence for the nearby, persistent WISE source being a high-redshift object; in fact, a detection of the source in DELS $z$-band rules out a redshift $z>7.3$. We present our findings as a cautionary tale of the dangers of passing asteroids for photometric selections.

Read this paper on arXiv…

S. Bosman, F. Davies and E. Bañados
Wed, 12 Apr 23
37/45

Comments: RNAAS; 2 pages, 1 figure