Spitzer SAGE-SMC Infrared Photometry of Massive Stars in the Small Magellanic Cloud

摘要

We present a catalog of 5324 massive stars in the Small Magellanic Cloud(SMC), with accurate spectral types compiled from the literature, and aphotometric catalog for a subset of 3654 of these stars, with the goal ofexploring their infrared properties. The photometric catalog consists of starswith infrared counterparts in the Spitzer, SAGE-SMC survey database, for whichwe present uniform photometry from 0.3-24 um in the UBVIJHKs+IRAC+MIPS24 bands.We compare the color magnitude diagrams and color-color diagrams to those ofthe Large Magellanic Cloud (LMC), finding that the brightest infrared sourcesin the SMC are also the red supergiants, supergiant B[e] (sgB[e]) stars,luminous blue variables, and Wolf-Rayet stars, with the latter exhibiting lessinfrared excess, the red supergiants being less dusty and the sgB[e] starsbeing on average less luminous. Among the objects detected at 24 um are a fewvery luminous hypergiants, 4 B-type stars with peculiar, flat spectral energydistributions, and all 3 known luminous blue variables. We detect a distinct Bestar sequence, displaced to the red, and suggest a novel method of confirmingBe star candidates photometrically. We find a higher fraction of Oe and Bestars among O and early-B stars in the SMC, respectively, when compared to theLMC, and that the SMC Be stars occur at higher luminosities. We estimatemass-loss rates for the red supergiants, confirming the correlation withluminosity even at the metallicity of the SMC. Finally, we confirm the newclass of stars displaying composite A & F type spectra, the sgB[e] nature of2dFS1804 and find the F0 supergiant 2dFS3528 to be a candidate luminous bluevariable with cold dust.