The X-ray luminosity function of bright galaxy clusters in the local universe

Citation
S. De Grandi et al., The X-ray luminosity function of bright galaxy clusters in the local universe, ASTROPHYS J, 513(1), 1999, pp. L17-L20
Citations number
29
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
513
Issue
1
Year of publication
1999
Part
2
Pages
L17 - L20
Database
ISI
SICI code
0004-637X(19990301)513:1<L17:TXLFOB>2.0.ZU;2-3
Abstract
We present the X-ray luminosity function (XLF) for clusters of galaxies der ived from the RASS1 Bright Sample. The sample, selected from the ROSAT All- Sky Survey in a region of 2.5 sr within the southern Galactic cap, contains 130 clusters with flux limits in the range similar to 3-4 x 10(12) ergs cm (-2) s(-1) in the 0.5-2.0 keV band. A maximum likelihood fit with a Schecht er function of the XLF over the entire range of luminosities (0.045-28.0 x 10(44) ergs s(-1)) gives alpha = 1.52(-0.11)(+0.11), L* = 3.80(-0.55)(+0.70 ) x 10(44) ergs s(-1), and A = 5.07 +/- 0.45 x 10(-7) Mpc(-3) (10(44) ergs s(-1))(alpha-1). We investigate possible evolutionary effects within the sa mple, out to our redshift limit (z similar to 0.3), finding no evidence for evolution. Our results are in good agreement with other local estimates of the XLF, implying that this statistic for the local universe is now well d etermined. Comparison with XLFs for distant clusters (0.3 < z < 0.6) shows that no evolution is present for L-X less than or similar to 10(44) ergs s( -1). However, we detect differences at the 3 sigma level between our local XLF and the distant one estimated by Henry et al. for the Einstein Extended Medium-Sensitivity Survey (EMSS) sample. This difference is still present when considering the EMSS sample revised by Nichol et al.