Bibcode
D'Avanzo, P.; Muñoz-Darias, T.; Casares, J.; Martínez-Pais, I. G.; Campana, S.
Bibliographical reference
Astronomy and Astrophysics, Volume 460, Issue 1, December II 2006, pp.257-260
Advertised on:
12
2006
Journal
Citations
8
Refereed citations
8
Description
Aims.We present a study of the neutron star X-Ray Transient Cen X-4. Our
aim is to look for any evidence of irradiation of the companion with a
detailed analysis of its radial velocity curve, relative contribution of
the donor star and Doppler tomography of the main emission lines.
Methods: .To improve our study all our data are compared with a set of
simulations that consider different physical parameters of the system,
like the disc aperture angle and the mass ratio. Results: .We
conclude that neither the radial velocity curve nor the orbital
variation of the relative donor's contribution to the total flux are
affected by irradiation. On the other hand, we do see emission from the
donor star at Hα and HeI λ5876 which we tentatively
attribute to irradiation effects. In particular, the Hα emission
from the companion is clearly asymmetric and we suggest is produced by
irradiation from the hot-spot. Finally, from the velocity of the HeI
λ5876 spot we constrain the disc opening angle to
α=7°-14°.