| Full text | |
| Author(s): |
Total Authors: 4
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| Affiliation: | [1] Univ Fed Rio de Janeiro, Observ Valongo, BR-20080090 Rio De Janeiro - Brazil
[2] IP&D Univ Vale Paraiba, BR-12244000 Sao Jose Dos Campos, SP - Brazil
[3] CEA, Div Astrofis, Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, SP - Brazil
[4] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 - USA
Total Affiliations: 4
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| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 399, n. 4, p. 2201-2220, NOV 11 2009. |
| Web of Science Citations: | 23 |
| Abstract | |
We use SDSS data to investigate the scaling relations of 127 No SOCS and 56 CIRS galaxy clusters at low redshift (z <= 0.10). We show that richness and both optical and X-ray luminosities are reliable mass proxies. The scatter in mass at a fixed observable is similar to 40 per cent, depending on the aperture, sample and observable considered. For example, for the massive CIRS systems sigma(lnM500 vertical bar N500) = 0.33 +/- 0.05 and sigma(lnM500 vertical bar Lx) = 0.48 +/- 0.06. For the full sample sigma(lnM500 vertical bar N500) = 0.43 +/- 0.03 and sigma(llnM500 vertical bar Lx) = 0.56 +/- 0.06. The scaling relations based only on the richer systems ( CIRS) are slightly flatter than those based on the full sample, but the discrepancies are within 1 sigma. We estimate substructure using 2D and 3D optical data, verifying that substructure has no significant effect on the cluster scaling relations ( intercepts and slopes), independent of which substructure test we use. For a subset of 21 clusters, we estimate masses from the M-T(X) relation using temperature measures from Base de Donnees Amas de Galaxies X. The scaling relations derived from the optical and X-ray masses are indeed very similar, indicating that our method consistently estimates the cluster mass and yields equivalent results regardless of the wavelength from which we measure mass. For massive systems, we represent the mass-richness relation by a function with the form ln(M(200)) = A + B x ln(N(200)/60), with M(200) being expressed in units of 10(14) M(circle dot). Using the virial mass, for CIRS clusters, we find A = (1.39 +/- 0.07) and B = (1.00 +/- 0.11). For the same sample, but using the masses obtained by the caustic method, we get A = (0.64 +/- 0.14) and B = (1.35 +/- 0.34). If we consider the mass as estimated from T(X) ( for the subset of 21 clusters with T(X) available) we derive A = (0.90 +/- 0.10) and B = (0.92 +/- 0.10). The relations based on the virial mass have a scatter of sigma(lnM200 vertical bar N200) = 0.37 +/- 0.05, while sigma(lnM200 vertical bar N200) = 0.77 +/- 0.22 for the caustic mass and sigma(lnM200N200) = 0.34 +/- 0.08 for the temperature-based mass. (AU) | |
| FAPESP's process: | 06/04955-1 - Scaling relations and photometric properties of galaxy clusters |
| Grantee: | Paulo Afranio Augusto Lopes |
| Support Opportunities: | Research Grants - Young Investigators Grants |