1996/01/30 by Takamitsu Miyaji, T. Miyaji, Miyaji, Takamitsu +12
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9601173
Accepted to A&A, 11 pages, a LaTeX text, 4 postscript figures, and l-aa.sty are tar'd, gzip'ed and uuencoded
arxiv created 1996/01/30 · openalex publication_date 1996/01/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We have made cross-correlation analyses of (2 -- 15 keV) HEAO A2 and 1 keV ROSAT PSPC All-Sky Survey maps over a selected area (∼ 4000 deg2) with high galactic latitude (b>40 deg). We have calculated the correlations for the bright ROSAT sources and residual background separately with the \HEAO A2 TOT (2 -- 10 keV) and HRD (5 -- 15 keV) maps. The amplitude of the bright \ROSAT source -- A2 CCFs are consistent with expectations from model populations of AGNs and clusters of galaxies, which emit in both bands. However, the residual ROSAT background -- A2 CCFs amplitude at zero degree are about a factor of three larger than that expected from the model populations. Our soft-hard zero-lag and angular CCF results have been compared with the 1 keV auto-correlation function (ACF) found by Soltan et al. (1995) for the same ROSAT data. Their significant angular CCF at a scale of < 5 deg is of an unknown origin and it could represent a new class of cosmic X-ray sources. If this 1 keV ACF has a hot plasma spectrum with kT∼ 2 keV, contribution of this component is consistent with both our zero-lag CCF in excess of the population synthesis model prediction and the upper-limit to the angular CCF at θ∼ 2.5 deg. On the other hand, if this component has a lower temperature or a steeper spectrum, a major modification to the population synthesis model and/or an introduction of new classes would be needed.