The XMM-NEWTONΩproject
| Autor: | Chris A. Collins, Douglas Burke, Robert C. Nichol, David H. Lumb, M. Giard, Alain Blanchard, Ph. Marty, A. K. Romer, S C Vauclair, Jukka Nevalainen, R. Sadat, J. Bartlett |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | Astronomy & Astrophysics. 420:853-872 |
| ISSN: | 1432-0746 0004-6361 |
| DOI: | 10.1051/0004-6361:20035687 |
| Popis: | We describe XMM-Newton Guaranteed Time observations of a sample of eight high redshift (0.45< z < 0.62) clusters. The goal of these observations was to measure the luminosity and the temperature of the clusters to a precision of 10%, leading to constraints on the possible evolution of the luminosity-temperature (Lx-Tx) relation, and ultimately on the values of the matter density, M, and, to a lesser extent, the cosmological constant . The clusters were drawn from the SHARC and 160 Square Degree (160SD) ROSAT surveys and span a bolometric (0.0-20 keV) luminosity range of 2.0 to 14.4 1044 ergs (H0=50, M=1, =0). Here we describe our data analysis techniques and present, for the first time with XMM-Newton, a Lx-Tx relation. For each of the eight clusters in the sample, we have measured total (r < rvirial) bolometric luminosities, performed -model fits to the radial surface profiles and made spectral fits to a single temperature isothermal model. We describe data analysis techniques that pay particular attention to background mitigation. We have also estimated temperatures and luminosities for two known clusters (Abell 2246 and RX J1325.0-3814), and one new high redshift cluster candidate (XMMU J084701.8+345117), that were detected off-axis. Characterizing the Lx-Tx relation as Lx = L6 ((T)/(6 keV)), we find L6=15.9 +7.6-5.2 1044 ergs and =2.70.4 for an =0.0, M =1.0, H0=50 km s-1 Mpc-1 cosmology at a typical redshift z 0.55. Comparing with the low redshift study by Markevitch (1998), we find to be in agreement, and assuming Lx-Tx to evolve as (1+z){A }, we find A=0.680.26 for the same cosmology and A= 1.52+0.26-0.27 for an =0.7, M=0.3 cosmology. Our A values are very similar to those found previously by Vikhlinin et al. (2002) using a compilation of Chandra observations of 0.39 |
| Databáze: | OpenAIRE |
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