The Open UniversitySkip to content

Infrared spectroscopy of the Be/X-ray transient A0535+26

Clark, J. S.; Steele, I. A.; Coe, M. J. and Roche, P. (1998). Infrared spectroscopy of the Be/X-ray transient A0535+26. Monthly Notices of the Royal Astronomical Society, 297(3) pp. 657–666.

Full text available as:
PDF (Not Set) - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (418Kb)
DOI (Digital Object Identifier) Link:
Google Scholar: Look up in Google Scholar


We present infrared spectroscopy of the Be /X-ray binary HDE 245770/A0535+26 obtained over the period 1992–1995. The spectra show significant variability, reflecting changes in the circumstellar environment during this time. A reduction in the flux observed in the Paschen series lines between 1993 December and 1994 September correlates with a similar reduction in both the strength of Ha and the optical continuum emission, which can be attributed to a reduction in the emission measure of the disc. A turnover between optically thin and thick emission is seen for both Paschen and Brackett series lines, and allows an estimate of the disc density as 11012 cmÃ�3. Echelle spectroscopy reveals strong similarities between the He I 1.008, 2.058 lm, Ha and Paschen series line profiles, suggesting their formation in a similar (and asymmetric) region of the disc. In contrast, the line profile of He I 6678 °A indicates that it is formed at smaller radii than the other transitions.

Item Type: Journal Article
ISSN: 1365-2966
Academic Unit/Department: Science > Physical Sciences
Interdisciplinary Research Centre: Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
Item ID: 17536
Depositing User: Users 9108 not found.
Date Deposited: 06 Jul 2009 12:42
Last Modified: 23 Feb 2016 21:16
Share this page:


Scopus Citations

Actions (login may be required)

Policies | Disclaimer

© The Open University   + 44 (0)870 333 4340