A search for Symbiotic Stars in the Local Group

TL;DR

This paper evaluates the potential of the Local Group Census survey to identify symbiotic star candidates across Local Group galaxies, using detection limits and diagnostic diagrams to distinguish them from other emission-line objects.

Contribution

It introduces methods to detect and differentiate symbiotic stars in Local Group galaxies using specific photometric diagnostics and estimates their expected numbers.

Findings

Detection limits for symbiotic stars in survey data

Diagnostic diagrams for star classification

Estimated number of symbiotic stars in surveyed galaxies

Abstract

The Local Group Census is a narrow- and broad-band survey of all the galaxies of the Local Group above dec = -30 deg, in progress at the 2.5m Isaac Newton telescope on La Palma. We discuss here the ability of the survey to detect symbiotic star candidates in the Local Group, by deriving detection limits in each of the narrow- and broad-band frames used in the survey, and by estimating the total number of objects expected in each galaxy. We present two diagnostic diagrams, based on the adopted photometric filters, to discriminate between symbiotic stars and other emission-line objects such as planetary nebulae.