THE XMM CLUSTER SURVEY: ACTIVE GALACTIC NUCLEI AND STARBURST GALAXIES IN XMMXCS J2215.9-1738 AT z = 1.46

Journal Article · Tue Jul 20 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/718/1/133· OSTI ID:21455160

Hilton, Matt ^[1]; Lloyd-Davies, Ed; Romer, A Kathy; Hosmer, Mark; Liddle, Andrew R; Mehrtens, Nicola ^[2]; Stanford, S Adam ^[3]; Stott, John P; Collins, Chris A ^[4]; Hoyle, Ben ^[5]; Kay, Scott T ^[6]; Miller, Christopher J ^[7]; Sahlen, Martin ^[8]; Viana, Pedro T. P., ^[9]

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1. Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa)
2. Astronomy Centre, University of Sussex, Falmer, Brighton, BN1 9QH (United Kingdom)
3. University of California, Davis, CA 95616 (United States)
4. Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD (United Kingdom)
5. Institut de Ciencies del Cosmos (ICCUB), Departmento de Fisica, MartI i Franques 1, 08034 Barcelona (Spain)
6. University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire, SK11 9DL (United Kingdom)
7. Astronomy Department, University of Michigan, Ann Arbor, MI 48109 (United States)
8. Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden)
9. Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

We use Chandra X-ray and Spitzer infrared (IR) observations to explore the active galactic nucleus (AGN) and starburst populations of XMMXCS J2215.9-1738 at z = 1.46, one of the most distant spectroscopically confirmed galaxy clusters known. The high-resolution X-ray imaging reveals that the cluster emission is contaminated by point sources that were not resolved in XMM-Newton observations of the system, and have the effect of hardening the spectrum, leading to the previously reported temperature for this system being overestimated. From a joint spectroscopic analysis of the Chandra and XMM-Newton data, the cluster is found to have temperature T = 4.1{sup +0.6}{sub -0.9} keV and luminosity L {sub X} = (2.92{sup +0.24} {sub -0.35}) x 10{sup 44} erg s{sup -1}, extrapolated to a radius of 2 Mpc. As a result of this revised analysis, the cluster is found to lie on the {sigma} {sub v}-T relation, but the cluster remains less luminous than would be expected from self-similar evolution of the local L {sub X}-T relation. Two of the newly discovered X-ray AGNs are cluster members, while a third object, which is also a prominent 24 {mu}m source, is found to have properties consistent with it being a high-redshift, highly obscured object in the background. We find a total of eight >5{sigma} 24 {mu}m sources associated with cluster members (four spectroscopically confirmed and four selected using photometric redshifts) and one additional 24 {mu}m source with two possible optical/near-IR counterparts that may be associated with the cluster. Examining the Infrared Array Camera colors of these sources, we find that one object is likely to be an AGN. Assuming that the other 24 {mu}m sources are powered by star formation, their IR luminosities imply star formation rates {approx}100 M{sub sun} yr{sup -1}. We find that three of these sources are located at projected distances of <250 kpc from the cluster center, suggesting that a large amount of star formation may be taking place in the cluster core, in contrast to clusters at low redshift.

• OSTI ID: 21455160
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 718; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
EMISSION
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
GALAXY CLUSTERS
GALAXY NUCLEI
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
POINT SOURCES
RADIATION SOURCES
RED SHIFT
RESOLUTION
STAR EVOLUTION
STARS
X-RAY GALAXIES