|Written by Administrator|
|Monday, 23 June 2008 15:57|
The legacy of Mid to Far-infrared surveys of the Galactic Plane is rich in scientific discovery. Unbiased surveys make possible dramatic leaps in our understanding because they provide homogeneous data for a large number of objects allowing firm statistical inferences about global properties. Systematically executed, large surveys such as IRAS, MSX, GLIMPSE and MIPSGAL dramatically changed, and are still shaping, our understanding of the Galactic ecosystem.
While Herschel is unique in tracing the peak of the Spectral Energy Distribution of cold dust, and hence its temperature and luminosity, in star-forming complexes and the ISM at unparalleled resolutions, the full potential of Hi-GAL will be delivered if put in the context of other Galactic Plane surveys.
In this sense Hi-GAL will be the keystone of a system of complementary existing or already approved Galactic Plane surveys from the near-IR (GLIMPSE, MSX, MIPSGAL) to the millimeter (SCUBA2, LaBoCa, Bolocam) which will provide complete coverage of the dust thermal continuum of the Galactic Plane at ≈ 20″ spatial resolution over nearly three decades in wavelength. Radio continuum from the CORNISH unbiased survey (presently limited to the inner 1st Galactic Quadrant) allows to trace free-free emission from ionized plasma which is an important discriminator for the evolutionary stage of massive young Stellar Objects.
In addition to continuum surveys, ancillary spectroscopic data will be key not only in tracing the gas/dust ratio toward Hi-GAL sources, but also, and perhaps more important, in allowing systematic assignments of distance estimates needed for conversion of flux into masses and luminosities.
|Last Updated on Monday, 23 June 2008 20:12|