First Hi-GAL global view of star formation in the Milky Way
Molinari S., Pestalozzi M., Elia D., Schisano E., Testi L., et al.
Hi-GAL is a Herschel key-project that maps the Galactic plane in five photometric bands (centered at 70, 160, 250, 350 and 500 μm) with an unprecedented spatial resolution and sensitivity. Being sensitive to the peak of the dust emission of the Galaxy, Hi-GAL then detects what we can consider to be the coldest and therefore youngest objects in the Milky Way. With 280 square degrees of spatial coverage currently achieved, Hi-GAL delivers catalogs with tens of thousands candidate young stellar objects in different evolutionary stages and distributed in a variety of Galactocentric radii and environmental conditions. With our huge spectral energy distribution atlas, at least an order of magnitude above existing databases from previous surveys, it is possible for the first time to conduct studies on solid statistical grounds. In particular it is now possible to accurately trace evolutionary sequences and spatial distributions of objects in different stages of evolution. This talk presents the first attempt to extrapolate a global view on high-mass star formation in the Milky Way, exploiting Hi-GAL data accompained by ancillary VLSR measurements.