Issue |
A&A
Volume 479, Number 1, February III 2008
|
|
---|---|---|
Page(s) | 283 - 300 | |
Section | Online catalogs and data | |
DOI | https://doi.org/10.1051/0004-6361:20077687 | |
Published online | 04 December 2007 |
XMM-Newton observations of the Lockman Hole: X-ray source catalogue and number counts*
1
Max-Planck-Institut für extraterrestrische Physik, 85478 Garching, Germany e-mail: hbrunner@mpe.mpg.de
2
Instituto de Física de Cantabria (CSIC-UC), 39005 Santander, Spain
3
Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
4
ESO,Karl-Schwarschild-Strasse 2, 85748 Garching, Germany
Received:
20
April
2007
Accepted:
27
November
2007
Context.The Lockman Hole field represents the sky area of lowest Galactic line-of-sight
column density cm-2. It was observed by the XMM-Newton X-ray observatory
in 18 pointings for a total of 1.16 Ms (raw EPIC pn observing time)
constituting the deepest XMM-Newton exposure so far. After the removal of time intervals
with high particle background, the final effective exposure was 637 ks.
Aims.We present a catalogue of the X-ray sources detected in the central 0.196 deg2 of the field and discuss the derived number counts and X-ray colours.
Methods.The analysis was performed using the XMM-SAS data analysis package version 6.0. The detection sensitivity and fraction of spurious detections was calibrated using Monte Carlo simulations.
Results.In the 0.5-2.0 keV band, a sensitivity limit (defined as the faintest detectable source)
of erg cm-2 s-1 was reached.
The 2.0-10.0 keV band and 5.0-10.0 keV band sensitivity limits
were
erg cm-2 s-1 and
erg cm-2 s-1, respectively.
A total of 409 sources above a detection likelihood of 10 (3.9 sigma)
were found within a radius of 15′ off the field centre, of which
340, 266, and 98 sources were detected in the soft,
hard, and very hard bands, respectively. The number counts in each energy band
are in close agreement with results from previous surveys and with the synthesis
models of the X-ray background. Six percent of the Compton-thick source candidates have been
selected from the X-ray colour-colour diagram. This fraction is consistent with the
most recent predictions of X-ray background population synthesis
models at our flux limits.
We also estimated, for the first time, the
relation for Compton-thick AGN.
Key words: surveys / galaxies: active / galaxies: quasars: general / X-rays: galaxies / X-rays: general
© ESO, 2008
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