Identification of Herbig Ae/Be Stars in the Small Magellanic Cloud

Abstract

Protoplanetary disks orbiting intermediate-mass stars, Herbig Ae/Be stars, that have formed in a metal-poor environment may evolve differently than their Galactic cousins. A study of the planet-formation process in such an environment requires identification and characterization of a sample of candidates. We have observed several stars in the Small Magellanic Cloud, a nearby metal-poor dwarf galaxy, that have optical spectral properties of Herbig Ae/Be stars, including strong Hα emission, blue continuum excess, and spectral types ranging from early G to B. Infrared spectra of these sources from the Spitzer Space Telescope show strong excess emission indicating the presence of silicate dust, molecular and atomic gas, and polycyclic aromatic hydrocarbons. We present an analysis of the likelihood that these candidates are Herbig Ae/Be stars. This identification is the necessary first step to future investigations that will examine the role of metallicity in the evolution of protoplanetary disks