Quiescent galaxies in a virialized cluster at redshift 2: evidence for accelerated size growth

Autor: Steven W. Allen, G. Brammer, S. A. Stanford, Adam Mantz, J. P. Willis, R. E. A. Canning, Emil Noordeh
Rok vydání: 2021
Předmět:
Zdroj: Noordeh, E, Canning, R E A, Willis, J P, Allen, S W, Mantz, A, Stanford, S A & Brammer, G 2021, ' Quiescent galaxies in a virialized cluster at redshift 2 : evidence for accelerated size growth ', Monthly Notices of the Royal Astronomical Society, vol. 507, no. 4, pp. 5272-5280 . https://doi.org/10.1093/mnras/stab2459
ISSN: 1365-2966
0035-8711
Popis: We present an analysis of the galaxy population in XLSSC 122, an X-ray selected, virialized cluster at redshift $z=1.98$. We utilize HST WFC3 photometry to characterize the activity and morphology of spectroscopically confirmed cluster members. The quiescent fraction is found to be $88^{+4}_{-20}$ per cent within 0.5$r_{500}$, significantly enhanced over the field value of $20^{+2}_{-2}$ per cent at $z\sim2$. We find an excess of "bulge-like" quiescent cluster members with Sersic index $n>2$ relative to the field. These galaxies are found to be larger than their field counterparts at 99.6 per cent confidence, being on average $63^{+31}_{-24}$ per cent larger at a fixed mass of $M_\star = 5\times10^{10} M_\odot$. This suggests that these cluster member galaxies have experienced an accelerated size evolution relative to the field at $z>2$. We discuss minor mergers as a possible mechanism underlying this disproportionate size growth.
9 pages, 7 figures, accepted for publication in MNRAS
Databáze: OpenAIRE
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