Séminaire/Seminar Galaxies |
| « Galaxy groups at z < 2.5 in near-infrared surveys: detection, quenched fractions » |
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Florian Sarron |
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Obtaining large sample of galaxy groups at redshift z>1.5 is crucial to better understand cluster formation and the role environment plays in shaping galaxy properties. While a systematic search for such systems is challenging, exploiting deep, near-infrared selected photometric data is a promising approach.
Using data from three of the deepest near-infrared surveys that were homogeneously reduced over 3 deg2, we build a pure sample of 448 candidate groups up to z=2.5 and study some of their properties. Group detection was performed using a new group finder algorithm, the DElaunay TEssellation ClusTer IdentiFication with photo-z (DETECTIFz), that identifies groups as stellar-mass over-densities (Sarron & Conselice 2021). In this talk, I will introduce the DETECTIFz algorithm, and our galaxy group catalogue. I will then present our results on the galaxy quenched fraction inside groups, that we showed is higher than in the field up to z=2.2. Finally, I will discuss the use of photometric probability density functions (PDF) to study galaxy stellar populations in dense environment in upcoming surveys Euclid and Rubin LSST. |
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jeudi 14 avril 2022 - 11:30 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |