NOAO >   Observing Info >   Approved Programs >   2011A-0194

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Proposal Information for 2011A-0194


PI: Takeshi Oka, University of Chicago, t-oka@uchicago.edu
Address: Department of Astronomy and Astrophysics, 5640 South Ellis Avenue, Chicago, IL 60637, USA

CoI: Tom Geballe, Gemini Observatory - North
CoI: Nick Indriolo, University of Illinois at Urbana-Champaign
CoI: Ben McCall, University of Illinois at Urbana-Champaign
CoI: Miwa Goto, Max Planck Institutue for Astronomy - Heidelberg
CoI: Tomonori Usuda, Subaru Telescope, NAOJ

Title: Continued Exploration of the Galactic Center's Central Molecular Zone by H3+ Spectroscopy

Abstract: Following up on our great progress at the Gemini South toward characterizing the newly discovered warm diffuse component of the Central Molecular Zone (CMZ) of the Galaxy with CO and H3+ spectroscopy, we propose to complete the basic observations using GNIRS on Gemini North during 2011A (and beyond if necessary). The revealing CO and H3+ spectra obtained with Phoenix at Gemini South on new and much more widespread sightlines through the CMZ, especially those obtained in 2009A and 2010A, are consistent with our interpretation, based on earlier data, that warm diffuse gas in the CMZ, discovered less than ten years ago, is very extensive and perhaps has a larger filling factor than any other gaseous environment there. However, to definitively test this conclusion it is essential observe on additional sightlines widely spaced through the CMZ. These additional key sightlines have yet to be observed in CO and in any H3+ lines, including in particular one key H3+ line, which serves as a thermometer. That line is coincident in wavelength with telluric lines of H2O that are strong and variable on Cerro Pachon; it is much more readily observable on Mauna Kea.


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