NOAO >   Observing Info >   Approved Programs >   2014A-0355

Small NOAO Logo

Proposal Information for 2014A-0355


PI: Brian Keeney, University of Colorado at Boulder (CASA), brian.keeney@colorado.edu
Address: Center for Astrophysics and Space Astronomy (CASA), Campus Box 389, Boulder, CO, 80309, USA

CoI: John Stocke, University of Colorado at Boulder (CASA)
CoI: David Syphers, University of Colorado at Boulder (CASA)
CoI: Charles Danforth, University of Colorado at Boulder (CASA)
CoI: Bart Wakker, University of Wisconsin at Madison (Astronomy)
CoI: Blair Savage, University of Wisconsin at Madison (Astronomy)
CoI: Simon Morris, University of Durham

Title: Confirming the Discovery of Massive 10^6 K Gas Reservoirs in Spiral-Rich Galaxy Groups

Abstract: Due to the unprecedented quality of far-UV spectra now being delivered by the Cosmic Origins Spectrograph on HST, we have discovered several examples of broad, shallow Ly-alpha and OVI absorption lines which appears to be 10^6 K gas in the vicinity of small groups of spiral galaxies. Because COS observations provide only pencil-beam probes through this gas, its full extent is not known by direct observation. But if this gas is >600 kpc in extent it contains >10^11 solar masses of gas and is a major reservoir of baryons and metals surrounding spiral galaxies. If this inference is correct, the presence of the hot gas in spiral-rich groups like the Local Group has significant implications for the cosmic baryon census ( 20% of the total) and galactic chemical evolution modeling (accretion reservoir for low metallicity gas). Here we propose to use GEMINI-N/GMOS multi-object spectroscopy to confirm this interpretation by verifying the presence of small spiral-rich groups around each absorber and determining if the velocity dispersion of the group matches the Ly -alpha and OVI thermal line widths. We propose our four best sight lines, containing seven OVI absorbers at z=0.06-0.14 based on COS and FUSE spectroscopy.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2014A-0355

noaoprop-help@noao.edu

Small NOAO Logo