Bibcode
de Martino, D.; Matt, G.; Mukai, K.; Bonnet-Bidaud, J.-M.; Gänsicke, B. T.; Gonzalez Perez, J. M.; Haberl, F.; Mouchet, M.; Solheim, J.-E.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 437, Issue 3, July III 2005, pp.935-945
Fecha de publicación:
7
2005
Revista
Número de citas
26
Número de citas referidas
23
Descripción
We report on the first pointed X-ray observations with XMM-Newton and
RXTE satellites of the X-ray source RX J0757.0+6306 = HT Cam. We detect
a strong 515 s X-ray modulation confirming the optical photometric
period found in 1998, which definitively assigns this source to the
intermediate polar class of magnetic cataclysmic variables. The lack of
orbital sidebands in the X-rays indicates that the X-ray period is the
spin period of the accreting white dwarf. Simultaneous ultraviolet and
optical B-band photometry acquired with the XMM-Newton Optical Monitor
and coordinated optical UBVRI photometric data acquired at the Nordic
Optical Telescope (La Palma) show that the optical pulse is in phase
with the X-rays and hence originates in the magnetically-confined
accretion flow. The lack of ultraviolet spin modulation suggests that
accretion-induced heating on the white dwarf surface is not important in
this source. Spectral analyses of XMM-Newton EPIC and RGS data show that
HT Cam has a multi-temperature spectrum and, contrary to most
intermediate polars, it does not suffer from strong absorption. With its
86 min orbital period, HT Cam is the third confirmed system of this
class below the 2-3 h period gap accreting at a low rate.