Bibcode
Shahbaz, T.; Charles, P. A.; Smale, A. P.; Naylor, T.; van Paradijs, J.; Hassall, B. J. M.; Callanan, P.
Bibliographical reference
Journal Article, Oxford Univ. Oxford, United Kingdom
Advertised on:
6
1996
Citations
0
Refereed citations
0
Description
Broadband optical spectra of a sample of 15 low-mass X-ray binaries
(LMXBs) is obtained in the range of 4000-9000 A. The spectra are fitted
with combinations of standard accretion disc models and secondary star
templates. The slope steepness relating to an optically thick accretion
disc and x-ray heating of the outer parts of the disc is discussed for
the sample of LMXbs in which the power-law indices of the accretion disk
flux distribution were determined. Optical spectra of X1705-250,
XB1905+00 and XB1916-053 are presented with optical line emission
detected in most of the sample. The Balmer lines H-alpha and H-beta are
found to generally be the strongest lines with mean equivalent widths of
3.7 and 1.9 A, respectively. The He(II) Lambda 4686 and the Bowen
CIII/NIII blend at Lambda 4640 are also observed, with equivalent widths
of 3.0 and 4.1 A, respectively. The Paschen lines are detected in Agl
X-1. Theses lines are also present in Cen X-4, GS2000+25. The systems in
which stellar features are detected are those in which the companions
are evolved and the source in which the mass accretion rate is low.