Identification of new Galactic symbiotic stars with SALT - I. Initial discoveries and other emission line objects
Abstract
We introduce the first results from an ongoing, systematic survey for new symbiotic stars selected from the AAO/UKST SuperCOSMOS Hα Survey. The survey aims to identify and characterize the fainter population of symbiotic stars under-represented in extant catalogues. The accreting white dwarfs (WDs) in symbiotic stars, fuelled by their red giant donors with high mass-loss rate winds, make them promising candidates for Type Ia supernovae. Several candidates were observed spectroscopically with the Southern African Large Telescope. A total of 12 bona fide and 3 possible symbiotic stars were identified. The most remarkable example is a rare carbon-rich symbiotic star that displays coronal [Fe X] λ6375 emission, suggesting it may be a supersoft X-ray source with a massive WD. Several other emission line objects with near-infrared colours similar to symbiotic stars are listed in an appendix, including six B[e] stars, four planetary nebulae (PNe), two possible Be stars, one [WC9] Wolf-Rayet (WR) central star of a PN and one WC9 WR star. These initial discoveries will help shape and refine the candidate selection criteria that we expect will uncover several more symbiotic stars as the survey progresses.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2014
- DOI:
- 10.1093/mnras/stu292
- arXiv:
- arXiv:1311.0797
- Bibcode:
- 2014MNRAS.440.1410M
- Keywords:
-
- surveys;
- binaries: symbiotic;
- stars: carbon;
- stars: emission-line;
- Be;
- stars: Wolf-Rayet;
- planetary nebulae: general;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for publication in MNRAS. 17 pages, 12 figures and 3 tables