| Full text | |
| Author(s): |
Oliveira, A. S.
[1]
;
Lima, H. J. F.
[1]
;
Steiner, J. E.
[2]
;
Borges, B. W.
[3]
;
Cieslinski, D.
[4]
Total Authors: 5
|
| Affiliation: | [1] Univ Vale Paraiba, IP&D, BR-12244000 Sao Jose Dos Campos, SP - Brazil
[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508900 Sao Paulo - Brazil
[3] Univ Fed Santa Catarina, BR-88905120 Ararangua, SC - Brazil
[4] Inst Nacl Pesquisas Espaciais, Div Astrofis, BR-12227010 Sao Jose Dos Campos, SP - Brazil
Total Affiliations: 4
|
| Document type: | Journal article |
| Source: | Monthly Notices of the Royal Astronomical Society; v. 444, n. 3, p. 2692-2699, NOV 1 2014. |
| Web of Science Citations: | 2 |
| Abstract | |
Close binary supersoft X-ray sources (CBSS) are considered strong candidates to Type Ia supernova progenitors, but very few CBSS are known in our Galaxy. The Galactic counterparts of the CBSS may be the V Sge stars, not detected in X-rays due to the strong absorption by the interstellar gas. Nevertheless, the number of members in the V Sge class is still small. In order to find new members, we selected QU Car for photometric and spectroscopic observations. The orbital period of this system was published in the literature as 10.9 h, determined from radial velocity data taken in 1979-1980, but posterior analysis of data taken in 2006-2007 did not confirm this period. We analysed the high variability of its emission line profiles with the temporal variance spectrum (TVS) technique. Besides, we recovered the 10.9 h orbital period from the radial velocities of the He II 4686 angstrom emission line and, for the first time, detected what may be the orbital modulation in the photometric data. This photometric modulation is present only in the lower brightness state data, when the flickering is attenuated. The inclusion of QU Car in the V Sge class is supported by many features like high/low states, strong winds, nebular lines and He II 4686 angstrom/H beta emission line ratios. However, the non-detection of the characteristic O VI 3811-34 angstrom lines in its spectrum claims against this classification. These lines, though, may be highly variable so additional spectra analysed with the TVS technique can, possibly, solve this question. (AU) | |
| FAPESP's process: | 10/12805-5 - Observational study of candidates to SN Ia progenitors |
| Grantee: | Helder José Farias Lima |
| Support Opportunities: | Scholarships in Brazil - Master |
| FAPESP's process: | 03/12618-7 - Structure and evolution of V Sagittae stars, CBSS and related objects |
| Grantee: | Alexandre Soares de Oliveira |
| Support Opportunities: | Scholarships abroad - Research |