NOAO >   Observing Info >   Approved Programs >   2017A-0055

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Program Information for 2017A-0055


PI: Brian Keeney, U. of Colorado, brian.keeney@colorado.edu
Address: Center for Astrophysics and Space Astronomy, 389 UCB, Boulder, CO 80309 USA

CoI: John Stocke, U. of Colorado
CoI: Ben Oppenheimer, U. of Colorado
CoI: Charles Danforth, U. of Colorado

Title: Probing Hot Gas found by in Spiral-Rich Galaxy Groups

Abstract: While even relatively low-quality UV QSO spectra easily detect enormous photo-ionized gaseous halos surrounding late-type galaxies, only the few high-S/N ($>20$) hst/ COS spectra find examples of very broad, shallow lya and OVI absorption lines consistent with $10^5$- $10^{6.5}$~K collisionally-ionized gas. This new class of absorbers appears to be associated with the halos of entire small groups of spiral galaxies. Based on the importance for galaxy evolution of this enormous gas reservoir (if $>600$~kpc in extent it contains $>10^{11}~M_{odot}$), we have an approved hst Cycle~23 Medium-sized (45~orbit) project to detect and study hot gas absorbers associated with a pre-selected sample of spiral-rich galaxy groups. We propose to obtain WIYN/HYDRA spectra of the fainter group galaxies for detailed group characterizations (e.g., luminosity functions, spiral fractions and velocity dispersions) to compare with the UV absorption-line detections; e.g., does the velocity dispersion of these groups match the expectations based on gas temperatures inferred from lya and OVI line widths? We request 2~nights to observe 6-7~sightlines from our approved hst program.

Program Type: Standard/Extragalactic

Scheduled Nights:
Run 1 (2017A):  WIYN/HYDR -- 1n on Mar 02 2017


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 >   2017A-0055

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