8th HEAD Meeting, 8-11 September, 2004
Session 2 Galaxy Clusters and the Intergalactic Medium
Poster, Wednesday, September 8, 2004, 9:00am-10:00pm

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[2.24] The quest to detect X-ray IGM

A. Rasmussen, F. Paerels (Columbia Astrophysics Laboratory), S. M. Kahn (Stanford University), J.-W. den Herder, C. de Vries (Space Research Organization of the Netherlands)

Several efforts have been made since the availability of Chandra and XMM/Newton observatories to find evidence for a putative diffuse IGM at X-ray temperatures that trace the total mass distribution in the local universe. While careful analysis of X-ray emission from the outer regions of clusters of galaxies sometimes reveal presence of marginally more soft X-ray emission than expected (AKA the soft excess phenomenon), spectroscopic measures to detect line absorption by intervening systems toward bright, backlight AGNs have led only to very tentative detections that beg better statistics. Using megaseconds of archival XMM/Newton RGS data, combined with high quality spectroscopic data that probe structure of the local ISM, we characterize the extragalactic component of the absorption spectrum toward three lines of sight previously reported (3C273, PKS2155-304 and Mrk 421). We will also briefly describe preliminary design parameters for YADEX: a wide field, X-ray redshift survey mission that may stand a fighting chance to map the mass distribution structure in the local universe.


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Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.