2000/10/20 by Andrzej M. Soltan, Soltan, Andrzej M., Michael J. Freyberg +1
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0010414
4 pages, 3 figures (1ab, 2a, 2b), to be published in the proceedings of "X-Ray Astronomy 2000", eds. R. Giacconi, L. Stella & S. Serio, ASP Conf. Ser
arxiv created 2000/10/20 · arxiv updated 2009/12/01
The first positive detection of the X-ray background fluctuations at small angular scales is reported. ROSAT PSPC archive pointed observations are used to measure fluctuations at scales of 0.03 - 0.4 deg. The pointings have been selected from an area free from galactic contamination. At separations below 0.1 deg clusters of galaxies become a substantial source of the background fluctuations. The autocorrelation function of the fluctuations in the power law approximation has a slope of ~1 for all the data but is substantially flatter (with slope of ~0.7) when pointings containing bright clusters are removed. At separations 0.3 - 0.4 deg where the ACF estimates based on the ROSAT pointings and All-Sky Survey are available, both data sets give consistent results.