GAS ACCRETION IS DOMINATED BY WARM IONIZED GAS IN MILKY WAY MASS GALAXIES AT z {approx} 0

Journal Article · Sat Nov 10 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/759/2/137· OSTI ID:22086372

Joung, M Ryan; Putman, Mary E; Bryan, Greg L; Fernandez, Ximena; Peek, J E. G., ^[1]

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1. Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)

We perform high-resolution hydrodynamic simulations of a Milky Way mass galaxy in a fully cosmological setting using the adaptive mesh refinement code, Enzo, and study the kinematics of gas in the simulated galactic halo. We find that the gas inflow occurs mostly along filamentary structures in the halo. The warm-hot (10{sup 5} K 10{sup 6} K) ionized gases are found to dominate the overall mass accretion in the system (with M-dot = 3-5 M {sub Sun} yr{sup -1}) over a large range of distances, extending from the virial radius to the vicinity of the disk. Most of the inflowing gas (by mass) does not cool, and the small fraction that manages to cool does so primarily close to the galaxy (R {approx}< 100 kpc, with more pronounced cooling at smaller R), perhaps comprising the neutral gas that may be detectable as, e.g., high-velocity clouds. The neutral clouds are embedded within larger, accreting filamentary flows, and represent only a small fraction of the total mass inflow rate. The inflowing gas has relatively low metallicity (Z/Z {sub Sun} < 0.2). The outer layers of the filamentary inflows are heated due to compression as they approach the disk. In addition to the inflow, we find high-velocity, metal-enriched outflows of hot gas driven by supernova feedback. Our results are consistent with observations of halo gas at low z.

• OSTI ID: 22086372
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 759; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
COMPRESSION
COMPUTERIZED SIMULATION
COOLING
COSMOLOGY
DISTANCE
GALACTIC EVOLUTION
HYDRODYNAMICS
IONIZED GASES
LAYERS
MASS
METALS
MILKY WAY
RESOLUTION
STAR ACCRETION
VELOCITY