%0 Generic %1 stocke2017circumgalactic %A Stocke, John %A Keeney, Brian %A Danforth, Charles %A Oppenheimer, Ben %A Pratt, Cameron %A Berlind, Andreas %D 2017 %K association galaxy gas group warm %T The Warm Circum-Galactic Medium: 10^5-6 K Gas Associated with a Single Galaxy Halo or with an Entire Group of Galaxies? %U http://arxiv.org/abs/1702.08554 %X In preparation for a Hubble Space Telescope (HST) observing project using the Cosmic Origins Spectrograph (COS), the positions of all AGN targets having high-S/N far-UV G130M spectra were cross-correlated with a large catalog of low-redshift galaxy groups homogeneously selected from the spectroscopic sample of the Sloan Digital Sky Survey (SDSS). Searching for targets behind only those groups at z = 0.1-0.2 (which places the OVI doublet in the wavelength region of peak COS sensitivity) we identified only one potential S/N = 15-20 target, FBQS 1010+3003. An OVI-only absorber was found in its G130M spectrum at z = 0.11326, close to the redshift of a foreground small group of luminous galaxies at z = 0.11685. Because there is no associated Lyalpha absorption, any characterization of this absorber is necessarily minimal; however, the OVI detection likely traces "warm" gas in collisional ionization equilibrium at T ~ 300,000 K. While this discovery is consistent with being interface gas between cooler, photoionized clouds and a hotter intra-group medium, it could also be warm, interface gas associated with the circum-galactic medium (CGM) of the single closest galaxy. In this case a detailed analysis of the galaxy distribution (complete to 0.2 L*) strongly favors the individual galaxy association. This analysis highlights the necessity of both high-S/N > 20 COS data and a deep galaxy redshift survey of the region in order to test more rigorously the association of OVI-absorbing gas with a galaxy group. A Cycle 23 HST/COS program currently is targeting 10 UV-bright AGN behind 12 low-redshift galaxy groups to test the warm, group gas hypothesis.

@misc{stocke2017circumgalactic, abstract = {In preparation for a Hubble Space Telescope (HST) observing project using the Cosmic Origins Spectrograph (COS), the positions of all AGN targets having high-S/N far-UV G130M spectra were cross-correlated with a large catalog of low-redshift galaxy groups homogeneously selected from the spectroscopic sample of the Sloan Digital Sky Survey (SDSS). Searching for targets behind only those groups at z = 0.1-0.2 (which places the OVI doublet in the wavelength region of peak COS sensitivity) we identified only one potential S/N = 15-20 target, FBQS 1010+3003. An OVI-only absorber was found in its G130M spectrum at z = 0.11326, close to the redshift of a foreground small group of luminous galaxies at z = 0.11685. Because there is no associated Lyalpha absorption, any characterization of this absorber is necessarily minimal; however, the OVI detection likely traces "warm" gas in collisional ionization equilibrium at T ~ 300,000 K. While this discovery is consistent with being interface gas between cooler, photoionized clouds and a hotter intra-group medium, it could also be warm, interface gas associated with the circum-galactic medium (CGM) of the single closest galaxy. In this case a detailed analysis of the galaxy distribution (complete to 0.2 L*) strongly favors the individual galaxy association. This analysis highlights the necessity of both high-S/N > 20 COS data and a deep galaxy redshift survey of the region in order to test more rigorously the association of OVI-absorbing gas with a galaxy group. A Cycle 23 HST/COS program currently is targeting 10 UV-bright AGN behind 12 low-redshift galaxy groups to test the warm, group gas hypothesis.}, added-at = {2017-03-02T07:24:28.000+0100}, author = {Stocke, John and Keeney, Brian and Danforth, Charles and Oppenheimer, Ben and Pratt, Cameron and Berlind, Andreas}, biburl = {https://www.bibsonomy.org/bibtex/289c2d40c2da8ad2afee2470a882a9c4e/miki}, description = {[1702.08554] The Warm Circum-Galactic Medium: 10^5-6 K Gas Associated with a Single Galaxy Halo or with an Entire Group of Galaxies?}, interhash = {6e9f81d6273a6e22a121f3b134aeadcc}, intrahash = {89c2d40c2da8ad2afee2470a882a9c4e}, keywords = {association galaxy gas group warm}, note = {cite arxiv:1702.08554Comment: 11 pages, 3 figures, submitted to ApJ}, timestamp = {2017-03-02T07:24:28.000+0100}, title = {The Warm Circum-Galactic Medium: 10^5-6 K Gas Associated with a Single Galaxy Halo or with an Entire Group of Galaxies?}, url = {http://arxiv.org/abs/1702.08554}, year = 2017 }