CfA OIR Division Lunch Talks
Wednesday, September 26, 2012, 11:00 am, Pratt Conference Room

The Diffuse Galactic Light:
The Local Milky Way in Reflection

Timothy Brandt (Princeton)

More than just a foreground, Galactic dust plays important roles in star and planet formation and in chemistry in the interstellar medium. Dust was first observed as dark bands in the Milky Way, as "clouds" blocking light from more distant stars. The wavelength dependence of extinction has long provided important clues to the composition and size distribution of dust grains. Much of this extinction is scattering, and I will present the first measured spectra of the Diffuse Galactic Light: the local Milky Way in reflection. By correlating over 90,000 SDSS spectra of the blank sky with infrared dust maps, we detect stellar spectral features and even interstellar medium emission lines in scattered light. With radiative transfer models of the local Galaxy, these scattered spectra constrain the local stellar population, interstellar medium conditions, and dust grain properties.