Query : 2011A&A...529A.133E

2011A&A...529A.133E - Astronomy and Astrophysics, volume 529A, 133-133 (2011/5-1)

X-ray observations of PKS 0745-191 at the virial radius: are we there yet.


Abstract (from CDS):

We reassess the properties of the ICM at large radii in the galaxy cluster PKS 0745-191 in light of recent Suzaku measurements. We analyze an archival 10.5ks ROSAT/PSPC observation to extract the surface-brightness profile of PKS 0745-191 and infer the deprojected density profile. We then compare the ROSAT surface-brightness profile with the Suzaku result. We perform a mass analysis by combining the ROSAT density profile and the published temperature profiles from different instruments. We find that the ROSAT surface-brightness profile is statistically inconsistent (7.7σ) with the Suzaku result around and beyond the value of r200 estimated by Suzaku. We argue that, thanks to its large field of view and low background, ROSAT/PSPC is to the present day the most sensitive instrument for studying low surface-brightness X-ray emission in the 0.4-2.0keV band. We also note that the Suzaku temperature and mass profiles are at odds with the results from at least two other satellites (XMM-Newton and Swift).The difference in surface brightness between ROSAT and Suzaku is most likely explained by the existence of additional foreground components at the low Galactic latitude of the source, which were not taken into account in the Suzaku background modeling. In light of our mass analysis, we conclude that any estimate of the fraction of the virial radius reached by X-ray measurements is affected by systematic errors of the order of 25%. As a result, the properties of the ICM at the virial radius are still uncertain, and the Suzaku results on PKS 0745-191 should be considered with caution.

Abstract Copyright:

Journal keyword(s): galaxies: clusters: individual: PKS 0745-191 - X-rays: galaxies: clusters - galaxies: clusters: intracluster medium

Simbad objects: 5

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Number of rows : 5
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024
1 ClG 0745-19 ClG 07 47 31.3 -19 17 40           ~ 371 0
2 2MASX J07473129-1917403 BiC 07 47 31.3247085936 -19 17 40.013334276   19.60       ~ 407 1
3 NAME Lockman Hole reg 10 45 00.0 +58 00 00           ~ 831 0
4 NAME North Polar Spur ISM 12 00 +00.0           ~ 366 1
5 ACO 1795 ClG 13 48 50.48 +26 35 07.4           ~ 1261 0

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