Marginal likelihoods of distances and extinctions to stars: computation and compact representation

S. E. Sale , J. Magorrian (1)

1 IAP - Institut d'Astrophysique de Paris

We present a method for obtaining the likelihood function of distance and extinction to a star given its photometry. The other properties of the star (its mass, age, metallicity and so on) are marginalized assuming a simple Galaxy model. We demonstrate that the resulting marginalized likelihood function can be described faithfully and compactly using a Gaussian mixture model. For dust mapping applications we strongly advocate using monochromatic over bandpass extinctions, and provide tables for converting from the former to the latter for different stellar types.

Keywords: methods: statistical; stars: distances; dust; extinction; Astrophysics - Astrophysics of Galaxies; Astrophysics - Instrumentation and Methods for Astrophysics; Astrophysics - Solar and Stellar Astrophysics

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]

S. E. Sale, J. Magorrian. Marginal likelihoods of distances and extinctions to stars: computation and compact representation. Monthly Notices of the Royal Astronomical Society, 2015, 448, pp.1738-1750. ⟨10.1093/mnras/stv068⟩. ⟨insu-03644976⟩