New Insights into the Milky Way Galaxy
Deokkeun An (Caltech/IPAC)
I present two recent observational results, which can provide constraints on models of galaxy formation and evolution. First, I report on photometric metal abundance estimates for individual main-sequence stars in the Virgo Overdensity, which is believed to be the remains of a merging dwarf galaxy in the Galactic halo. I discuss the principles behind the technique that is based on a calibration of the metallicity sensitivity of stellar isochrones in the Sloan Digital Sky Survey (SDSS) passbands. Second, I report the detection of several molecular gas-phase and ice absorption features in three photometrically-selected young stellar object (YSO) candidates in the central 280 pc of the Milky Way. Our spectra, obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, demonstrate the youth of these objects, and provide the first spectroscopic identification of massive YSOs in the Galactic Center.
Contact: Juna Kollmeier
Deokkeun An (Caltech/IPAC)
I present two recent observational results, which can provide constraints on models of galaxy formation and evolution. First, I report on photometric metal abundance estimates for individual main-sequence stars in the Virgo Overdensity, which is believed to be the remains of a merging dwarf galaxy in the Galactic halo. I discuss the principles behind the technique that is based on a calibration of the metallicity sensitivity of stellar isochrones in the Sloan Digital Sky Survey (SDSS) passbands. Second, I report the detection of several molecular gas-phase and ice absorption features in three photometrically-selected young stellar object (YSO) candidates in the central 280 pc of the Milky Way. Our spectra, obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, demonstrate the youth of these objects, and provide the first spectroscopic identification of massive YSOs in the Galactic Center.
Contact: Juna Kollmeier