The Atacama cosmology telescope: flux upper limits from a targeted search for extragalactic transients

• DOI: 10.1093/mnras/stae583
• Publication Date: 2024-02-22T23:27:26Z
• Authors: Carlos Hervías-Ca...; Sigurd Naess; Adam D Hincks; Erminia Calabrese; Mark J Devlin; Jo Dunkley; Rolando Dünner; Patricio A Gallardo; Matt Hilton; Anna Y Q Ho; Kevin M Huffenberger; Xiaoyi Ma; Mathew S Madhavac...; Michael D Niemack; John Orlowski-Sch...; Lyman A Page; Bruce Partridge; Roberto Puddu; Maria Salatino; Cristóbal Sifón; Suzanne T Staggs; Cristian Vargas; Eve M Vavagiakis; Edward J Wollack
• Keywords: transients: supernovae; High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); FOS: Physical sciences; cosmic background radiation; methods: data analysis; transients: tidal disruption events; 01 natural sciences; 520; 13. Climate action; 0103 physical sciences; transients: gamma-ray bursts; Astrophysics - High Energy Astrophysical Phenomena; Astrophysics - Cosmology and Nongalactic Astrophysics

ABSTRACT We have performed targeted searches of known extragalactic transient events at millimetre wavelengths using nine seasons (2013–2021) 98, 150, and 229 GHz Atacama Cosmology Telescope (ACT) observations that mapped ∼40 per cent the sky for most data volume. Our cover 88 gamma-ray bursts (GRBs), 12 tidal disruption (TDEs), 203 other transients, including supernovae (SNe). stack our ACT to increase signal-to-noise ratio maps. In all cases but one, we do not detect these transients in data. The single candidate detection (event AT2019ppm), seen ∼5σ significance data, appears be due active galactic nuclei activity host galaxy coincident with a alert. For each source search provide flux upper limits. example, medians 95 confidence limits 98 are 15, 18, 16 mJy GRBs, SNe, TDEs, respectively, first month after discovery. projected sensitivity future wide-area cosmic microwave background surveys should sufficient many methods described this paper.