Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-03-12
A&A 529, A133 (2011)
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
6 pages, 5 figures, accepted for publication in A&A
Scientific paper
10.1051/0004-6361/201116575
We wish to reassess the properties of the ICM at large radii in the galaxy cluster PKS 0745-191 in light of the recent Suzaku measurements. We analyze an archival 10.5 ksec 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 combining the ROSAT density profile and the published temperature profiles from different instruments. We find that the ROSAT surface-brightness profile is statistically inconsistent (7.7 sigma) 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 to low surface-brightness X-ray emission in the 0.4-2.0 keV 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 measures 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 should be considered with caution.
Eckert Dominique
Gastaldello Fabio
Molendi Silvano
Rossetti Mariachiara
No associations
LandOfFree
X-ray observations of PKS 0745-191 at the virial radius: Are we there yet? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with X-ray observations of PKS 0745-191 at the virial radius: Are we there yet?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray observations of PKS 0745-191 at the virial radius: Are we there yet? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-279185