DEMOGRAPHICS AND PHYSICAL PROPERTIES OF GAS OUTFLOWS/INFLOWS AT 0.4 < z < 1.4

Journal Article · Sat Dec 01 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/760/2/127· OSTI ID:22086246

Martin, Crystal L ^[1]; Shapley, Alice E; Kornei, Katherine A ^[2]; Coil, Alison L ^[3]; Bundy, Kevin ^[4]; Weiner, Benjamin J ^[5]; Noeske, Kai G ^[6]; Schiminovich, David ^[7]

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1. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
2. Department of Physics and Astronomy, University of California, Los Angeles, CA 90025 (United States)
3. Center for Astrophysics and Space Sciences, Department of Physics, University of California, San Diego, CA 92093 (United States)
4. Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583 (Japan)
5. Steward Observatory, 933 N. Cherry St., University of Arizona, Tucson, AZ 85721 (United States)
6. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
7. Department of Astronomy, Columbia University, New York, NY 10027 (United States)

We present Keck/LRIS spectra of over 200 galaxies with well-determined redshifts between 0.4 and 1.4. We combine new measurements of near-ultraviolet, low-ionization absorption lines with previously measured masses, luminosities, colors, and star formation rates to describe the demographics and properties of galactic flows. Among star-forming galaxies with blue colors, we find a net blueshift of the Fe II absorption greater than 200 km s{sup -1} (100 km s{sup -1}) toward 2.5% (20%) of the galaxies. The fraction of blueshifted spectra does not vary significantly with stellar mass, color, or luminosity but does decline at specific star formation rates less than roughly 0.8 Gyr{sup -1}. The insensitivity of the blueshifted fraction to galaxy properties requires collimated outflows at these redshifts, while the decline in outflow fraction with increasing blueshift might reflect the angular dependence of the outflow velocity. The low detection rate of infalling gas, 3%-6% of the spectra, suggests an origin in (enriched) streams favorably aligned with our sightline. We find that four of these nine infalling streams have projected velocities commensurate with the kinematics of an extended disk or satellite galaxy. The strength of the Mg II absorption increases with stellar mass, B-band luminosity, and U - B color, trends arising from a combination of more interstellar absorption at the systemic velocity and less emission filling in more massive galaxies. Our results provide a new quantitative understanding of gas flows between galaxies and the circumgalactic medium over a critical period in galaxy evolution.

• OSTI ID: 22086246
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 760; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTRA
ASTRONOMY
ASTROPHYSICS
COLOR
GALACTIC EVOLUTION
GALAXIES
GAS FLOW
IONIZATION
MAGNESIUM IONS
PHOTON EMISSION
QUASARS
RED SHIFT
STAR EVOLUTION
STARS
ULTRAVIOLET RADIATION