2012A&A...545A..41B


C.D.S. - SIMBAD4 rel 1.7 - 2019.12.12CET06:55:06

2012A&A...545A..41B - Astronomy and Astrophysics, volume 545A, 41-41 (2012/9-1)

Self-similarity of temperature profiles in distant galaxy clusters: the quest for a universal law.

BALDI A., ETTORI S., MOLENDI S. and GASTALDELLO F.

Abstract (from CDS):

We present the XMM-Newton temperature profiles of 12 bright (LX>4x1044erg/s) clusters of galaxies at 0.4<z<0.9, having an average temperature in the range 5≲kT≲11keV. The main goal of this paper is to study for the first time the temperature profiles of a sample of high-redshift clusters, to investigate their properties, and to define a universal law to describe the temperature radial profiles in galaxy clusters as a function of both cosmic time and their state of relaxation. We performed a spatially resolved spectral analysis, using Cash statistics, to measure the temperature in the intracluster medium at different radii. We extracted temperature profiles for the clusters in our sample, finding that all profiles are declining toward larger radii. The normalized temperature profiles (normalized by the mean temperature T500) are found to be generally self-similar. The sample was subdivided into five cool-core (CC) and seven non cool-core (NCC) clusters by introducing a pseudo-entropy ratio σ=(TIN/TOUT)x(EMIN/EMOUT)–1/3 and defining the objects with σ<0.6 as CC clusters and those with σ≥0.6 as NCC clusters. The profiles of CC and NCC clusters differ mainly in the central regions, with the latter exhibiting a slightly flatter central profile. A significant dependence of the temperature profiles on the pseudo-entropy ratio σ is detected by fitting a function of r and σ, showing an indication that the outer part of the profiles becomes steeper for higher values of σ (i.e. transitioning toward the NCC clusters). No significant evidence of redshift evolution could be found within the redshift range sampled by our clusters (0.4<z<0.9). A comparison of our high-z sample with intermediate clusters at 0.1<z<0.3 showed how the CC and NCC cluster temperature profiles have experienced some sort of evolution. This can happen because higher z clusters are at a less advanced stage of their formation and did not have enough time to create a relaxed structure, which is characterized by a central temperature dip in CC clusters and by flatter profiles in NCC clusters. This is the first time that a systematic study of the temperature profiles of galaxy clusters at z>0.4 has been attempted. We were able to define the closest possible relation to a universal law for the temperature profiles of galaxy clusters at 0.1<z<0.9, showing a dependence on both the relaxation state of the clusters and the redshift.

Abstract Copyright:

Journal keyword(s): galaxies: clusters: intracluster medium - X-rays: galaxies: clusters

Simbad objects: 12

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Number of rows : 12

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 ClG 0016+16 ClG 00 18 33.3 +16 26 36           ~ 468 0
2 ClG J0030+2618 ClG 00 30 33.6 +26 18 16           ~ 56 0
3 ClG 0451-03 ClG 04 54 10.9 -03 01 07     20.0     ~ 324 0
4 ClG J0647+7015 ClG 06 47 50.0 +70 14 55           ~ 121 0
5 ClG J0744+3927 ClG 07 44 52.5 +39 27 30           ~ 152 0
6 MCXC J0856.1+3756 ClG 08 56 08.5 +37 56 52           ~ 13 0
7 2MASS J09134545+4056282 Sy2 09 13 45.4949162350 +40 56 28.214305677   19.69 19.21     ~ 230 2
8 ACO 851 ClG 09 42 56.6 +46 59 22           ~ 305 0
9 MCS J1206.2-0847 ClG 12 06 12.2 -08 48 02           ~ 171 0
10 ClG J1226+3332 ClG 12 26 57.7 +33 32 50           ~ 190 0
11 ClG J1347-1145 ClG 13 47 33.5 -11 45 42           ~ 453 0
12 1RXS J222834.4+203647 ClG 22 28 37.1 +20 36 31           ~ 98 0

    Equat.    Gal    SGal    Ecl

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2019.12.12-06:55:06

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