X-RAY SPECTROSCOPY OF AS1101 WITH CHANDRA, XMM-NEWTON, AND ROSAT: BANDPASS DEPENDENCE OF THE TEMPERATURE PROFILE AND SOFT EXCESS EMISSION

Journal Article · Sat Sep 10 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/738/2/149; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21584891

Bonamente, Massimiliano ^[1]; Nevalainen, Jukka ^[2]

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1. Physics Department, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)
2. Finnish Center for Astronomy with ESO, University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland)

We present spatially resolved spectroscopy of the galaxy cluster AS1101, also known as Sersic 159-03, with Chandra, XMM-Newton, and ROSAT, and investigate the presence of soft X-ray excess emission above the contribution from the hot intracluster medium. In earlier papers we reported an extremely bright soft excess component that reached 100% of the thermal radiation in the R2 ROSAT band (0.2-0.4 keV), using the H I column density measurement by Dickey and Lockman. In this paper we use the newer Leiden-Argentine-Bonn survey measurements of the H I column density toward AS1101, significantly lower than the previous value, and show that the soft excess emission in AS1101 is now at the level of 10%-20% of the hot gas emission, in line with those of a large sample of clusters analyzed by Bonamente et al. in 2002. The ROSAT soft excess emission is detected regardless of calibration uncertainties between Chandra and XMM-Newton. This new analysis of AS1101 indicates that the 1/4 keV band emission is compatible with the presence of warm-hot intergalactic medium (WHIM) filaments connected to the cluster and extending outward into the intergalactic medium; the temperatures we find in this study are typically lower than those of the WHIM probed in other X-ray studies. We also show that the soft excess emission is compatible with a non-thermal origin as the inverse Compton scattering of relativistic electrons off the cosmic microwave background, with pressure less than 1% of the thermal electrons.

• OSTI ID: 21584891
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 738; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BASIC INTERACTIONS
COMPTON EFFECT
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
EMISSION
GALAXY CLUSTERS
INTERACTIONS
IONIZING RADIATIONS
MICROWAVE RADIATION
RADIATIONS
RELICT RADIATION
SCATTERING
SOFT X RADIATION
SPECTROSCOPY
X RADIATION
X-RAY SPECTROSCOPY