Volume 489, Number 3, October III 2008
|Page(s)||1121 - 1127|
|Section||Galactic structure, stellar clusters, and populations|
|Published online||11 September 2008|
Properties of the Galactic population of cataclysmic variables in hard X-rays
Max-Planck-Institute für Astrophysik, Karl-Schwarzschild-Str. 1, 85740 Garching bei München, Germany e-mail: firstname.lastname@example.org
2 Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia
3 Excellence Cluster Universe, Technische Universität München, Garching, Germany
Accepted: 23 July 2008
We measure the spatial distribution and hard X-ray luminosity function of cataclysmic variables (CVs) using the INTEGRAL all-sky survey in the 17–60 keV energy band. The vast majority of CVs detected by INTEGRAL are intermediate polars of luminosity in the range 1032–1034 erg s-1. The scale height of the Galactic disk population of intermediate polars is found to be pc. The CV luminosity function measured with INTEGRAL in hard X-rays is compatible with that previously determined at lower energies (3–20 keV) using a largely independent sample of sources detected by RXTE (located at |b| > 10° as opposed to the INTEGRAL sample, which is strongly concentrated to the Galactic plane). The cumulative 17–60 keV luminosity density of CVs per unit stellar mass is found to be (1.3±0.3)1027 erg s-1 , which is comparable to that of low-mass X-ray binaries in this energy band. Therefore, faint but numerous CVs are expected to provide an important contribution to the cumulative hard X-ray emission of galaxies.
Key words: stars: binaries: close / stars: binaries: general / stars: novae, cataclysmic variables / stars: luminosity function, mass function / stars: white dwarfs / X-rays: binaries
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.