PI: T. Oka, University of Chicago, firstname.lastname@example.org
Address: Department of Astronomy and Astrophysics, 5640 South Ellis Avenue, Chicago, IL 60637, USA
CoI: T. R. Geballe, Gemini Observatory
Title: Study of the gas in the Central Molecular Zone of the Galactic center by H3+ spectroscopy (continuation)
Abstract: We propose to use GNIRS high resolution spectroscopy of H3+ and CO toward selected dust-embedded stars in the Galactic center to (1) constrain the physical conditions in and extent of the warm diffuse gas within the Central Molecular Zone (CMZ) of the Galaxy and simultaneously to (2) determine the morphology and kinematics of the Expanding Molecular Ring (EMR) located on the outer edge of the CMZ. Our current data strongly suggest that the warm diffuse gas with high ionization rate fills a large fraction of the volume of the CMZ, but those data have wide gaps in longitudinal coverage. Likewise, the current limited data imply that the motion of the EMR is that of simple radial expansion, which is at odds with more complex interpretations based on observations of dense clouds in the Ring. We now have a selection of suitable stars (most of them found using Gemini) to cover the entire longitudinal range of the CMZ/EMR with roughly even longitudinal spacing. This will allow us to probe many well-separated sightlines passing through the CMZ and the EMR.
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