The Rotation Speed of the Companion Star in Aquila X-1

Shahbaz, T.; Casares, J.; Charles, P. A.
Bibliographical reference

Technical Report, OUAST/97/12 Dept. of Astrophysics

Advertised on:
1
1997
Number of authors
3
IAC number of authors
1
Citations
0
Refereed citations
0
Description
We have obtained medium resolution spectra of the neutron star X-ray transient Aql X-1 during quiescence. We determine the spectral type of the companion star to be K1 and also estimate its rotation speed to be 62(+30/-20) km/s. By measuring the width of the H-alpha emission line profile of the accretion disc, we estimate the binary inclination to approx. 50 deg and also estimate the semi-amplitude of the companion star's radial velocity curve to be approx. 170 km/s.