ALMAGAL III. Compact source catalog

We characterize and discuss the revealed fragmentation properties and the photometric and estimated physical parameters of the core population. The ALMAGAL compact source catalog includes 6348 cores detected in 844 clumps (83% of the total), with a number of cores per clump between 1 and 49 (median of 5). The estimated core diameters are mostly within ~800-3000au (median of 1700au).

We assigned core temperatures based on the L/M of the hosting clump, and obtained core masses from 0.002 to 345M_{sun}_ (complete above 0.23M_{sun}_), exhibiting a good correlation with the core radii (M~R^2.6). We evaluated the variation in the core mass function (CMF) with evolution as traced by the clump L/M, finding a clear, robust shift and change in slope among CMFs within subsamples at different stages. This finding suggests that the CMF shape is not constant throughout the star formation process, but rather it builds (and flattens) with evolution, with higher core masses reached at later stages.

We found that all cores within a clump grow in mass on average with evolution, while a population of possibly newly formed lower-mass cores is present throughout. The number of cores increases with the core masses, at least until the most massive core reaches ~10M_{sun}_. More generally, our results favor a clump-fed scenario for high-mass star formation, in which cores form as low-mass seeds, and then gain mass while further fragmentation occurs in the clump.