Characterizing the Circumgalactic Medium of Nearby Galaxies

Type Conference Paper
Names Brian A. Keeney, J. T. Stocke, C. Danforth, B. D. Savage, C. S. Froning, J. C. Green
Proceedings Title American Astronomical Society
Conference Name AAS Meeting #223, #237.05
Date January 1, 2014
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Abstract We have detected and characterized the circumgalactic medium (CGM) of nearby late-type galaxies using both targeted and serendipitous QSO/galaxy pairs at z < 0.2. Photoionization modeling of warm CGM clouds finds volume filling factors of ~5%, cloud sizes of 0.1-30 kpc, cloud masses of 10-108 M⊙, and metallicities of ~0.1-1 Z⊙. The total mass of these warm clouds surrounding L > 0.1 L* galaxies approaches 1010 M⊙, comparable to the total baryons in massive galaxy disks. We also find evidence for an extensive (>500 kpc), hot (105 - 106 K) intracloud medium that is very massive (> 1011 M⊙). We interpret this hot, massive baryon reservoir as the intragroup medium of spiral-rich galaxy groups and find that its inclusion can solve the missing baryon problem in spiral galaxies.
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