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Full-Text Articles in Physical Sciences and Mathematics
Probing Outflows In Z = 1~2 Galaxies Through Fe Ii/Fe Ii Multiplets, Yuping Tang, Mauro Giavalisco, Yicheng Guo, Jaron Kurk
Probing Outflows In Z = 1~2 Galaxies Through Fe Ii/Fe Ii Multiplets, Yuping Tang, Mauro Giavalisco, Yicheng Guo, Jaron Kurk
Mauro Giavalisco
We report on a study of the 2300 − 2600°A Fe II/Fe II∗ multiplets in the rest–UV spectra of star forming galaxies at 1.0 < z < 2.6 as probes of galactic–scale outflows. We extracted a mass–limited sample of 97 galaxies at z _ 1.0 − 2.6 from ultra–deep spectra obtained during the GMASS spetroscopic survey in the GOODS South field with the VLT and FORS2. We obtain robust measures of the rest equivalent width of the Fe II absorption lines down to a limit of Wr > 1.5°A and of the Fe II∗ emission lines to Wr > 0.5°A. Whenever we can measure the systemic redshift of the galaxies from the [O II] emission line, we find that both the Fe II and Mg II absorption lines are blueshifted, indicative that both species trace gaseous outflows. We also find, however, that the Fe II gas has generally lower outflow velocity relative to that of Mg II. We investigate the variation of Fe II line …
Molecular Gas Content Of Hi Monsters And Implications To Cold Gas Content Evolution In Galaxies, Cheoljong Lee, Aeree Chung, Min S. Yun, Ryan Cybulski, Gopal Narayanan, N. Erickson
Molecular Gas Content Of Hi Monsters And Implications To Cold Gas Content Evolution In Galaxies, Cheoljong Lee, Aeree Chung, Min S. Yun, Ryan Cybulski, Gopal Narayanan, N. Erickson
Gopal Narayanan
No abstract provided.
The Neutral Hydrogen Content Of Galaxies In Cosmological Hydrodynamic Simulations, Romeel Dave, Neal S. Katz, Benjamin D. Oppenheimer, Juna A. Kollmeier, David H. Weinberg
The Neutral Hydrogen Content Of Galaxies In Cosmological Hydrodynamic Simulations, Romeel Dave, Neal S. Katz, Benjamin D. Oppenheimer, Juna A. Kollmeier, David H. Weinberg
Neal S. Katz
We examine the global H I properties of galaxies in quarter billion particle cosmological simulations using GADGET-2, focusing on how galactic outflows impact H I content. We consider four outflow models, including a new one (ezw) motivated by recent interstellar medium simulations in which the wind speed and mass loading factor scale as expected for momentum-driven outflows for larger galaxies and energy-driven outflows for dwarfs (σ < 75 km s−1). To obtain predicted H I masses, we employ a simple but effective local correction for particle self-shielding and an observationally constrained transition from neutral to molecular hydrogen. Our ezw simulation produces an H I mass function whose faint-end slope of −1.3 agrees well with observations from the Arecibo Fast Legacy ALFA survey; other models agree less well. Satellite galaxies have a bimodal distribution in H I fraction versus halo mass, with smaller satellites and/or those in larger haloes more often being H I deficient. At a given stellar mass, H I content correlates with the star formation rate and inversely correlates with metallicity, as expected if driven by stochasticity in the accretion rate. To higher redshifts, massive H I galaxies disappear and the mass function steepens. The global cosmic H I density conspires to remain fairly constant from z ∼ 5 → 0, but the relative contribution from smaller galaxies increases with redshift.