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Daniel Christlein |
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"A Spectroscopic Tour of
the Outer Disks of Galaxies" |
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Far more than just featureless repositories of leftover gas, the outer disks of spiral galaxies are being recognized as a unique environment that hosts both stars and star formation and bears the traces of a galaxy's formation and evolution. Over the past years, we have explored very deep optical spectroscopy as an avenue to the study of the outer disks. Very low surface brightness H-alpha emission can be traced up to 50% beyond the conventional optical radius R_25, twice as far as typical optical rotation curves, and competitive with 21-cm observations. I will present results on the surface brightness profiles and kinematic properties of these outer disks. |