1999/04/21 by C. W. Churchill, Christopher W. Churchill, Richard R. Mellon +10 · 4 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/312102
Accepted to Astrophysical Journal Letters; 4 pages; 3 figures; emulateapj.sty
arxiv created 1999/04/21 · openalex publication_date 1999/07/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We have examined Faint Object Spectrograph data from the Hubble Space Telescope archive for C IV λλ1548, 1550 absorption associated with 40 Mg II λλ2796, 2803 absorption-selected galaxies at 0.4 ≤ z ≤ 1.4. We report a strong correlation between Mg II kinematics, measured in ~6 km s -1 resolution HIRES/Keck spectra, and W r (1548); this implies a physical connection between the processes that produce "outlying velocity" Mg II clouds and high-ionization galactic/halo gas. We found no trend in ionization condition W r (1548)/ W r (2796) with galaxy-QSO line-of-sight separation for 13 systems with confirmed associated galaxies, suggesting no obvious ionization gradient with galactocentric distance in these intermediate-redshift galaxies. We find tentative evidence (2 σ) that W r (1548)/ W r (2796) is anticorrelated with galaxy B - K color; if further data corroborate this trend, in view of the strong C IV-Mg II kinematics correlation, it could imply a connection between stellar populations, star formation episodes, and the kinematics and ionization conditions of halo gas at z ~ 1.