Gum 31 is a prominent, but still rather poorly studied HII region around the stellar cluster NGC 3324 at the northwestern periphery of the Carina nebula complex. Our aim was to reveal and characterize the young stellar population in Gum 31. An X-ray survey is the only efficient way to identify young stars in this region with extremely high galactic field-star contamination that can avoid the strong biases of infrared excess selected samples of disk-bearing young stars. We used the Chandra observatory to perform a deep (70ks) X-ray observation of the Gum 31 region and detected 679 X-ray point sources. This extends and complements the X-ray survey of the central Carina nebula regions performed in the Chandra Carina Complex Project (CCCP). Using deep near-infrared images from our recent VISTA survey of the Carina nebula complex, our comprehensive Spitzer point-source catalog, and optical archive data, we identify counterparts for 75% of these X-ray sources.

Cone search capability for table J/A+A/564/A120/sources (Catalog of the Chandra X-ray sources in the Gum 31 region (table1), with near- and mid-infrared photometry (table3))