Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-12-15
Astronomy and Astrophysics
Astrophysics
20 pages, 30 Postscript figures, A&A in press
Scientific paper
10.1051/0004-6361:20041340
We report on the results of a detailed analysis of the X-ray spectral properties of a large sample of sources detected serendipitously with the XMM-Newton observatory in 25 selected fields. The survey covers a total solid angle of ~3.5 deg2 and contains 1137 sources with ~10E-15 < S0.5-10 < 10E-12 erg cm-2 s-1. We find evidence for hardening of the average X-ray spectra of the sources towards fainter fluxes. We interpret this as indicating a higher degree of photoelectric absorption amongst the fainter population. Absorption is detected at 95% confidence in 20% of the sources, but it could certainly be present in many other sources below our detection capabilities. For Broad Line AGNs (BLAGNs), we detect absorption in ~10% of the sources with column densities in the range 10E21 - 10E22 cm-2. The fraction of absorbed Narrow Emission Line galaxies (NELGs, most with intrinsic X-ray luminosities >10E43 erg s-1, and therefore classified as type 2 AGNs) is significantly higher (40%), with a hint of moderately higher columns. We do not find evidence for a redshift evolution of the underlying power law index of BLAGNs, which stays roughly constant at Gamma ~1.9, with intrinsic dispersion of 0.4. A small fraction (~7%) of BLAGNs and NELGs require the presence of a soft excess, that we model as a black body with temperature ranging from 0.1 to 0.3 keV. Comparing our results on absorption to popular X-ray background synthesis models, we find absorption in only ~40% of the sources expected. This is due to a deficiency of heavily absorbed sources (with NH ~10E22 - 10E24 cm-2) in our sample in comparison with the models. We therefore conclude that the synthesis models require some revision in their specific parameters.
Barcons Xavier
Caccianiga Alessandro
Carrera Francicso J.
Ceballos Maria Teresa
Lamer Georg
No associations
LandOfFree
X-ray spectra of XMM-Newton serendipitous medium flux sources does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with X-ray spectra of XMM-Newton serendipitous medium flux sources, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and X-ray spectra of XMM-Newton serendipitous medium flux sources will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-627792