How the Milky Ways ticks: comprehending complexity in the interstellar medium, from ethereal wisps to dense structures at the onset of star formation (part I!)
Nov 7, 2012
3:20PM to 4:20PM
Date(s) - 07/11/2012
3:20 pm - 4:20 pm
Title: How the Milky Ways ticks: comprehending complexity in the interstellar medium, from ethereal wisps to dense structures at the onset of star formation (part I!)
Speaker: Dr. Peter Martin
Institute: University of Toronto
Location: ABB 102
Understanding why, unlike in other galaxies, there is still an interstellar medium (ISM) in the Milky Way in which stars are continually forming requires a broad study of Galactic ecology: the cycling of the ISM from the diffuse atomic phase to dense molecular clouds, the sites of star formation, and back. Two satellites, the Planck Surveyor and the Herschel Space Observatory, which image thermal emission by cold interstellar dust particles tracing the gas, are helping us revolutionize this field. Each cost about a billion euros and I will give my two centsâ?? worth!
I will concentrate mostly on high Galactic latitudes where we see the return cycle, the interstellar cirrus, fairly local dust in the disk, as well as â??intermediate velocity clouds,â? part of the Galactic fountain, material thrust out of the disk and raining down from the halo (we have mapped the motion of the turbulent hydrogen gas with the 100-m Green Bank Telescope). But succumbing to temptation I will illustrate where this material ends up, in the star-forming molecular clouds spectacularly imaged by Herschel.