Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-11-24
Astron.Astrophys.419:837-848,2004
Astronomy and Astrophysics
Astrophysics
21 pages, 25 figures. Accepted for publication in Astronomy & Astrophysics
Scientific paper
10.1051/0004-6361:20034421
We have measured the spectrum of the Cosmic X-ray Background (CXB) in the 2-8 keV range with the high throughput EPIC/MOS instrument onboard XMM-Newton. A large sample of high galactic latitude observations was used, covering a total solid angle of 5.5 square degrees. Our study is based on a very careful characterization and subtraction of the instrumental background, which is crucial for a robust measurement of the faintest diffuse source of the X-ray sky. The CXB spectrum is consistent with a power law having a photon index Gamma=1.41+/-0.06 and a normalization of 2.46+/-0.09 photons/(cm^2 s sr keV) at 3 keV (~11.6 photons/(cm^2 s sr keV) at 1 keV), corresponding to a 2-10 keV flux of (2.24+/-0.16)x10^(-11) erg/(cm^2 s deg) (90% confidence level, including the absolute flux calibration uncertainty). Our results are in excellent agreement with two of the most recent CXB measurements, performed with BeppoSAX LECS/MECS data (Vecchi et al. 1999) and with an independent analysis of XMM-Newton EPIC/MOS data (Lumb et al. 2002), providing a very strong constrain to the absolute sky surface brightness in this energy range, so far affected by a ~40% uncertainty. Our measurement immediately implies that the fraction of CXB resolved by the recent deep X-ray observations in the 2-10 keV band is of 80+/-7% (1sigma), suggesting the existence of a new population of faint sources, largely undetected within the current sensitivity limits of the deepest X-ray surveys.
de Luca Andrea
Molendi Silvano
No associations
LandOfFree
The 2-8 keV cosmic X-ray background spectrum as observed with XMM-Newton 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 The 2-8 keV cosmic X-ray background spectrum as observed with XMM-Newton, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The 2-8 keV cosmic X-ray background spectrum as observed with XMM-Newton will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-19693