THE RADIAL AND AZIMUTHAL PROFILES OF Mg II ABSORPTION AROUND 0.5 < z < 0.9 zCOSMOS GALAXIES OF DIFFERENT COLORS, MASSES, AND ENVIRONMENTS

Journal Article · Sat Dec 10 00:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/743/1/10· OSTI ID:22004575

Bordoloi, R; Lilly, S J; Knobel, C; Kampczyk, P; Carollo, C M ^[1]; Bolzonella, M; Zucca, E; Zamorani, G; Bardelli, S ^[2]; Iovino, A ^[3]; Contini, T ^[4]; Kneib, J -P; Le Fevre, O ^[5]; Mainieri, V ^[6]; Renzini, A ^[7]; Scodeggio, M ^[8]; Balestra, I; Bongiorno, A ^[9]; Caputi, K ^[10]; Cucciati, O ^[11] ; others, and

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1. Institute for Astronomy, ETH Zuerich, Wolfgang-Pauli-Strasse 27, 8093 Zuerich (Switzerland)
2. INAF Osservatorio Astronomico di Bologna, Bologna (Italy)
3. INAF Osservatorio Astronomico di Brera, Milan (Italy)
4. Institut de Recherche en Astrophysique et Planetologie, CNRS, 14, Avenue Edouard Belin, F-31400 Toulouse (France)
5. Laboratoire d'Astrophysique de Marseille, CNRS/Aix-Marseille Universite, 38 rue Frederic Joliot-Curie, 13388 Marseille Cedex 13 (France)
6. European Southern Observatory, Garching (Germany)
7. Dipartimento di Astronomia, Universita di Padova, Padova (Italy)
8. INAF-IASF Milano, Milan (Italy)
9. Max Planck Institut fuer Extraterrestrische Physik, Garching (Germany)
10. SUPA, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 1BD (United Kingdom)
11. INAF-Osservatorio Astronomico di Trieste, Trieste (Italy)

We map the radial and azimuthal distribution of Mg II gas within {approx} 200 kpc (physical) of {approx} 4000 galaxies at redshifts 0.5 < z < 0.9 using co-added spectra of more than 5000 background galaxies at z > 1. We investigate the variation of Mg II rest-frame equivalent width (EW) as a function of the radial impact parameter for different subsets of foreground galaxies selected in terms of their rest-frame colors and masses. Blue galaxies have a significantly higher average Mg II EW at close galactocentric radii as compared to the red galaxies. Among the blue galaxies, there is a correlation between Mg II EW and galactic stellar mass of the host galaxy. We also find that the distribution of Mg II absorption around group galaxies is more extended than that for non-group galaxies, and that groups as a whole have more extended radial profiles than individual galaxies. Interestingly, these effects can be satisfactorily modeled by a simple superposition of the absorption profiles of individual member galaxies, assuming that these are the same as those of non-group galaxies, suggesting that the group environment may not significantly enhance or diminish the Mg II absorption of individual galaxies. We show that there is a strong azimuthal dependence of the Mg II absorption within 50 kpc of inclined disk-dominated galaxies, indicating the presence of a strongly bipolar outflow aligned along the disk rotation axis. There is no significant dependence of Mg II absorption on the apparent inclination angle of disk-dominated galaxies.

• OSTI ID: 22004575
• Journal Information: Astrophysical Journal, Vol. 743, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
GALACTIC EVOLUTION
GALAXIES
INCLINATION
QUASARS
RED SHIFT
ROTATION
STAR EVOLUTION