Aquila X-1: a low-inclination soft X-ray transient

Shahbaz, T.; Thorstensen, J. R.; Charles, P. A.; Sherman, N. D.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society, Volume 296, Issue 4, pp. 1004-1008.

Fecha de publicación:
6
1998
Número de autores
4
Número de autores del IAC
0
Número de citas
18
Número de citas referidas
18
Descripción
We have obtained I-band photometry of the neutron star X-ray transient Aql X-1 during quiescence. We find a periodicity at 2.487 cycles d^-1, which we interpret as twice the orbital frequency (19.30+/-0.05 h). Folding the data on the orbital period, we model the light-curve variations as the ellipsoidal modulation of the secondary star. We determine the binary inclination to be 20 deg-30 deg (90 per cent confidence) and also determine the 95 per cent upper limits to the radial velocity semi-amplitude and rotational broadening of the secondary star to be 117 and 50 km s^-1, respectively.