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 Ha 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] λ 6375 emission, suggesting it may be a supersoft X-ray source with a massive WD. Several other emission line objectswith 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 WC9WR 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. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.