Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-05-25
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
Accepted for publication in ApJ, 16 pages, 10 figures
Scientific paper
We use Chandra X-ray and Spitzer infrared observations to explore the 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 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 data, the cluster is found to have temperature T=4.1_-0.9^+0.6 keV and luminosity L_X=(2.92_-0.35^+0.24)x10^44 erg/s extrapolated to a radius of 2 Mpc. As a result of this revised analysis, the cluster is found to lie on the sigma_v-T relation, but the cluster remains less luminous than would be expected from self-similar evolution of the local L_X-T relation. Two of the newly discovered X-ray AGN are cluster members, while a third object, which is also a prominent 24 micron 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 micron sources associated with cluster members (four spectroscopically confirmed, and four selected using photometric redshifts), and one additional 24 micron source with two possible optical/near-IR counterparts that may be associated with the cluster. Examining the IRAC colors of these sources, we find one object is likely to be an AGN. Assuming that the other 24 micron sources are powered by star formation, their infrared luminosities imply star formation rates ~100 M_sun/yr. 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.
Collins Chris A.
Hilton Matt
Hosmer Mark
Hoyle Ben
Kay Scott T.
No associations
LandOfFree
The XMM Cluster Survey: Active Galactic Nuclei and Starburst Galaxies in XMMXCS J2215.9-1738 at z=1.46 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The XMM Cluster Survey: Active Galactic Nuclei and Starburst Galaxies in XMMXCS J2215.9-1738 at z=1.46, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The XMM Cluster Survey: Active Galactic Nuclei and Starburst Galaxies in XMMXCS J2215.9-1738 at z=1.46 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-604554