EDP Sciences
Free Access
Volume 415, Number 3, March I 2004
Page(s) 1009 - 1019
Section Interstellar and circumstellar matter
DOI https://doi.org/10.1051/0004-6361:20034160

A&A 415, 1009-1019 (2004)
DOI: 10.1051/0004-6361:20034160

BeppoSAX observations of soft X-ray intermediate polars

D. de Martino1, G. Matt2, T. Belloni3, F. Haberl4 and K. Mukai5

1  INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
2  Dipartimento di Fisica, Universita' degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy
    e-mail: matt@fis.uniroma3.it
3  INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, Merate, Italy
    e-mail: belloni@merate.mi.astro.it

4  Max-Planck-Institüt für Extraterrestrische Physik, Giessenbachstraße, Postfach 1312, 85741 Garching, Germany
    e-mail: fwh@mpe.mpg.de
5  Laboratory for High Energy Astrophysics, NASA/GSFC, Code 662, Greenbelt, MD 20771, USA
    e-mail: mukai@milkyway.gsfc.nasa.gov

(Received 5 August 2003 / Accepted 31 October 2003)

We present broad-band (0.1-90 keV) spectral and temporal properties of the three Intermediate Polars, RE 0751+144 (PQ Gem), RX J0558.0+5353 (V405 Aur) and RX J1712.6-2414 (V2400 Oph) based on simultaneous soft and hard X-ray observations with the BeppoSAX satellite. The analysis of their spectra over the wide energy range of BeppoSAX instruments allows us to identify the soft and hard X-ray components and to determine simultaneously their temperatures. The black-body temperatures of the irradiated poles of the white dwarf atmosphere are found to be 60-100 eV, much higher than those found in their synchronous analogues, the Polars. The temperature of the optically thin post-shock plasma is well constrained in RX J1712.6-2414 and in RE 0751+144 (13 and 17 keV) and less precisely determined in RX J0558.0+5353. In the first two systems evidence of subsolar abundances is found, similarly to that estimated in other magnetic Cataclysmic Variables. A Compton reflection component is present in RX J0558.0+5353 and in RE 0751+144 and it is favoured in RX J1712.6-2414. Its origin is likely at the irradiated white dwarf surface. Although these systems share common properties (a soft X-ray component and optical polarized radiation), their X-ray power spectra and light curves at different energies suggest accretion geometries that cannot be reconciled with a single and simple configuration.

Key words: accretion, accretion discs -- binaries: close -- stars: individual: RE 0751+144 (PQ Gem), RX J0558.0+5353 (V405 Aur), RX J1712.6-2414 (V2400 Oph) -- X-rays: binaries

Offprint request: D. de Martino, demartino@na.astro.it

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