A large fraction of the low redshift baryons is believed to reside in the warm-hot filamentary gas in the intergalactic medium (WHIM), which is hard to probe as much of the gas is shock heated to 105-107 K, making it invisible to all but low energy X-ray and UV observations.We used a statistical approach to detect WHIM in emission. The plasma filaments are expected to have a characteristic angular structure that can be identified and studied using the angular autocorrelation function (AcF). Using XMM-Newton data we found clear evidence of the WHIM emission in the energy band 0.4-0.6 keV and we quantified such emission as 12%±5% of the total Diffuse X-ray Background. We have also used both XMM-Newton and Chandra data to characterize the spatial distribution of the WHIM.
American Astronomical Society Meeting Abstracts #216
- Pub Date:
- May 2010