1999ApJ...519..518I

Query : 1999ApJ...519..518I

1999ApJ...519..518I - Astrophys. J., 519, 518-532 (1999/July-2)

Radial temperature profiles of X-ray-emitting gas within clusters of galaxies.

IRWIN J.A., BREGMAN J.N. and EVRARD A.E.

Abstract (from CDS):

Previous analyses of ASCA data of clusters of galaxies have found conflicting results regarding the slope of the temperature profile of the hot X-ray gas within clusters, mainly because of the large, energy-dependent point-spread function (PSF) of the ASCA mirrors. We present a summary of all ASCA-determined cluster temperature profiles found in the literature and find a discrepancy in the radial temperature trend of clusters based on which PSF-correction routine is used. This uncertainty in the cluster temperature profile in turn can lead to large uncertainties in the amount of dark matter in clusters. In this study, we have used ROSAT PSPC data to obtain independent relative temperature profiles for 26 clusters, most of which have had their temperature profiles determined by ASCA. Our aim is not to measure the actual temperature values of the clusters but to use X-ray color profiles to search for a hardening or softening of the spectra as a function of radius for comparison to ASCA-derived profiles. The radial color profiles indicate that outside of the cooling flow region, the temperature profiles of clusters are in general constant. Within 35% of the virial radius, we find that a temperature drop of 20% at 10 keV and 12% at 5 keV can be ruled out at the 99% confidence level. A subsample of non-cooling flow clusters shows that the condition of isothermality applies at very small radii too, although cooling gas complicates this determination in the cooling flow cluster subsample. The colors predicted from the temperature profiles of a series of hydrodynamical cluster simulations match the data very well, although they cannot be used to discriminate among different cosmologies. An additional result is that the color profiles show evidence for a central peak in metallicity in low-temperature clusters.

Abstract Copyright: ∼

Journal keyword(s): Galaxies: Cooling Flows - Galaxies: Clusters: General - Galaxies: Photometry - Galaxies: Intergalactic Medium - X-Rays: Galaxies

Simbad objects: 32

Full paper

View the references in ADS

Number of rows : 32

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag V	Sp type	#ref 1850 - 2026	#notes
1	ACO 85	ClG	00 41 36.21	-09 19 30.4		~	974	0
2	ACO 119	ClG	00 56 08.57	-01 12 00.8		~	577	2
3	2A 0251+413	ClG	02 54 26.6	+41 33 25		~	328	1
4	ACO 399	ClG	02 57 56.4	+13 00 59		~	420	0
5	ACO 401	ClG	02 58 50.3	+13 34 07		~	592	0
6	ACO 3112	ClG	03 17 52.9	-44 15 06		~	329	1
7	ZwCl 0335+0956	ClG	03 38 35.3	+09 57 54		~	402	1
8	ACO 478	ClG	04 13 24.8	+10 27 52		~	522	0
9	ACO 3266	ClG	04 31 26.4	-61 25 17		~	447	0
10	ACO 3391	ClG	06 26 15.4	-53 40 52		~	222	1
11	ACO 644	ClG	08 17 26.1	-07 31 13		~	241	0
12	ACO 665	ClG	08 30 45.2	+65 52 55		~	457	0
13	ACO 780	ClG	09 18 30	-12 15.7		~	469	0
14	ACO 1246	ClG	11 23 57.4	+21 29 14		~	118	0
15	MKW 3	ClG	11 48 29	-03 10.7	14.88	~	52	1
16	ACO 3526	ClG	12 48 49.2	-41 18 17		~	1154	2
17	ACO 1650	ClG	12 58 42.0	-01 45 45		~	325	0
18	ACO 1651	ClG	12 59 27.3	-04 10 49		~	307	0
19	ACO 3558	ClG	13 28 03.2	-31 31 35		~	476	2
20	ACO 3571	ClG	13 47 32.4	-32 50 12		~	308	2
21	ACO 1795	ClG	13 48 47.4	+26 34 55		~	1330	0
22	ACO 2029	ClG	15 10 54.2	+05 44 23		~	1020	0
23	ACO 2065	ClG	15 22 22.7	+27 44 20		~	398	0
24	ACO 2142	ClG	15 58 26.5	+27 13 52		~	825	0
25	ACO 2163	ClG	16 15 46.1	-06 08 50		~	586	0
26	ACO 2218	ClG	16 35 54.0	+66 13 00		~	827	1
27	BAX 249.5848-64.5165	ClG	16 38 13.2	-64 21 21		~	123	0
28	ACO 2256	ClG	17 03 37.5	+78 37 23		~	928	1
29	BAX 258.1082-23.3759	ClG	17 12 26.3	-23 21 38		~	303	0
30	ACO 2319	ClG	19 21 14.0	+43 56 57		~	495	1
31	ACO 2657	ClG	23 44 51.0	+09 08 40		~	280	3
32	ACO 4059	ClG	23 57 02.2	-34 45 58		~	400	1

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