Thick disk planetary nebulae

Abstract

In this work we attempt to find Planetary Nebulae(PNe) belonging to the thick disk population of the Galaxy, based on the proper motion and radial velocity data of the objects available in literature, by using a simulation and Bayesian likelihood analysis. Making use of the established kinematical properties of the thick disk/thin disk/halo (TD/D/H) population of the Galaxy, we compute likelihoods of TD/D/H membership of 66 nebulae by fully taking into account the uncertainties associated with their proper motion and radial velocity data. We find 12 candidate PNe whose probability of belonging to the thick disc is 80% or greater, of which 9 PNe have a TD membership probability greater than 90%. Spectroscopy of the TD candidates is being planned and we hope this will shed light on the chemical characteristics of the TD population of the Galaxy, in the context of Planetary nebulae.