Journal
ASTROPHYSICAL JOURNAL
Volume 815, Issue 2, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/815/2/91
Keywords
galaxies: dwarf; galaxies: evolution; galaxies: halos; intergalactic medium; quasars: absorption lines
Categories
Funding
- NASA from the Space Telescope Science Institute [HST-GO-11741, HST-GO-11598, HST-GO-12248, HST-AR-13894]
- NASA [NAS5-26555]
Ask authors/readers for more resources
To investigate the evolution of metal-enriched gas over recent cosmic epochs as well as to characterize the diffuse, ionized, metal-enriched circumgalactic medium, we have conducted a blind survey for C IV absorption systems in 89 QSO sightlines observed with the Hubble Space Telescope Cosmic Origins Spectrograph. We have identified 42 absorbers at z < 0.16, comprising the largest uniform blind sample size to date in this redshift range. Our measurements indicate an increasing C iv absorber number density per comoving path length (d.N/dX = 7.5 +/- 1.1) and modestly increasing mass density relative to the critical density of the universe (Omega(C) IV = 10.0 +/- 1.5 x 10(-8)) from z similar to 1.5 to the present epoch, consistent with predictions from cosmological hydrodynamical simulations. Furthermore, the data support a functional form for the column density distribution function that deviates from a single power law, also consistent with independent theoretical predictions. As the data also probe heavy element ions in addition to C iv at the same redshifts, we identify, measure, and search for correlations between column densities of these species where components appear to be aligned in velocity. Among these ion ion correlations, we find evidence for tight correlations between C II and Si II, C II and Si III, and C iv and Si Iv, suggesting that these pairs of species arise in similar ionization conditions. However, the evidence for correlations decreases as the difference in ionization potential increases. Finally, when controlling for observational bias, we find only marginal evidence for a correlation (86.8% likelihood) between the Doppler line width b(C IV) and column density N(C IV).
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available