Reclassifying symbiotic stars with 2MASS and WISE: An atlas of spectral energy distribution

Abstract

We present a new updated catalogue of Galactic and extragalactic symbiotic stars (SySts). Since the last catalogue of SySts (Belczynski et al. 2000), the number of known SySts has significantly increased. Our new catalogue contains 316 known and 82 candidates SySts. Of the confirmed Systs 252 are located in our Galaxy and 64 in nearby galaxies. This reflects an increase of $\sim$50% in the population of Galactic SySts and $\sim$400% in the population of extragalactic SySts. The spectral energy distribution (SED) of 334 (known and candidates) SySts have been constructed using the 2MASS and WISE data. These SEDs are used to provide a robust reclassification in scheme of S- (74%), D- (15%) and D'-types (2.5%). The SEDs of S- and D-type peak between 0.8 and 1.6$\mu$m and between 1.6 and 4$\mu$m, respectively, whereas those of D'-type exhibit a plateau profile. Moreover, we provide the first compilation of SySts that exhibit the OVI Raman-scattered line at 6830\AA. Our analysis shows that 55% of the Galactic SySts exhibit that line in their spectrum, whereas this percentage is different from galaxy to galaxy.