Spitzer/IRAC‐MIPS Survey of NGC 2244: Protostellar Disk Survival in the Vicinity of Hot Stars

We present the results from a survey of NGC 2244 from 3.6 to 24 micron withthe Spitzer Space Telescope. The 24micron-8micron-3.6micron color compositeimage of the region shows that the central cavity surrounding the multiple Oand B stars of NGC2244 contains a large amount of cool dust visible only at24micron. Our survey gives a detailed look at disk survivability within thehot-star-dominated environment in this cavity. Using mid infrared two colordiagrams ([3.6]-[4.5] vs [5.8]-[8.0]) we identified 337 class II and 25 class Iobjects out of 1084 objects detected in all four of these bands withphotometric uncertainty better than 10%. Including the 24 micron data, we found213 class II and 20 class I sources out of 279 stars detected also at thislatter band. The center of the class II density contours is in very goodagreement with the center of the cluster detected in the 2MASS images. Westudied the distribution of the class II sources relative to the O stars andfound that the effect of high mass stars on the circumstellar disks issignificant only in their immediate vicinity.Comment: 10 pages, 9 figures accepted for publication in Astrophysical Journa