We present a Spitzer Space Telescope imaging survey of the most massive Galactic globular cluster , \omega Centauri , and investigate stellar mass loss at low metallicity and the intracluster medium ( ICM ) .
The survey covers approximately 3.2 \times the cluster half-mass radius at 3.6 , 4.5 , 5.8 , 8 , and 24 µm , resulting in a catalog of over 40,000 point-sources in the cluster .
Approximately 140 cluster members ranging 1.5 dex in metallicity show a red excess at 24 µm , indicative of circumstellar dust .
If all of the dusty sources are experiencing mass loss , the cumulative rate of loss is estimated at 2.9 – 4.2 \times 10 ^ { -7 } ~ { } M _ { \odot } yr ^ { -1 } , 63 % – 66 % of which is supplied by three asymptotic giant branch stars at the tip of the Red Giant Branch ( RGB ) .
There is little evidence for strong mass loss lower on the RGB .
If this material had remained in the cluster center , its dust component ( \gtrsim 1 \times 10 ^ { -4 } ~ { } M _ { \odot } ) would be detectable in our 24 and 70 µm images .
While no dust cloud located at the center of \omega Cen is apparent , we do see four regions of very faint , diffuse emission beyond two half-mass radii at 24 µm .
It is unclear whether these dust clouds are foreground emission or are associated with \omega Cen .
In the latter case , these clouds may be the ICM in the process of escaping from the cluster .