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arXiv · 2304.05162

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

Sarah E. I. Bosman·Frederick B. Davies·Eduardo Bañados
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Abstract

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.

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Sarah E. I. Bosman, Frederick B. Davies, Eduardo Bañados. 2023-04-11. On the recent discovery claim of a new $z>7$ quasar. https://arxiv.org/abs/2304.05162

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