Title: New measurements of submillimeter spectral indices prompt a crisis for the protoplanetary disk demography
Speaker: Dr. Hau-Yu Liu (ASIAA)
Date: March 6 at 14:30
Location: R521, General Building II
Kepler Mission found that earth-sized planets or super-Earths are extremely common around solar-like stars, which has motivated extensive ALMA surveys towards protoplanetary disks to characterize the properties of the dust mass reservoirs for feeding terrestrial planet-formation, and to investigate where and how dust grains grow from (sub)micron sizes to millimeter or larger sizes. Those surveys (e.g., towards the Lupus, Taurus, Ophiuchus molecular clouds, etc.) coherently concluded that the median dust mass is about ten times the Earth mass, which is clearly insufficient for forming those rocky planets observed by Kepler Mission. I will explain why all of those previous measurements may have underestimated dust masses by 1-2 orders of magnitude, and have overestimates dust grain sizes by 2-3 orders of magnitude, due to overlooking a subtle radiative transfer effects.