13 research outputs found
Metal-enriched, subkiloparsec gas clumps in the circumgalactic medium of a faint z = 2.5 galaxy
We report the serendipitous detection of a 0.2 L*, Lyα emitting galaxy at redshift 2.5 at an impact parameter of 50 kpc from a bright background QSO sightline. A high-resolution spectrum of the QSO reveals a partial Lyman-limit absorption system (NHi=1016.94±0.10 cmâ2) with many associated metal absorption lines at the same redshift as the foreground galaxy. Using photoionization models that carefully treat measurement errors and marginalize over uncertainties in the shape and normalization of the ionizing radiation spectrum, we derive the total hydrogen column density NH=1019.4±0.3cmâ2, and show that all the absorbing clouds are metal enriched, with Z = 0.1â0.6âZâ. These metallicities and the system's large velocity width (436 kmâsâ 1) suggest the gas is produced by an outflowing wind. Using an expanding shell model we estimate a mass outflow rate of âŒ5âMââyrâ1. Our photoionization model yields extremely small sizes (<100â500 pc) for the absorbing clouds, which we argue is typical of high column density absorbers in the circumgalactic medium (CGM). Given these small sizes and extreme kinematics, it is unclear how the clumps survive in the CGM without being destroyed by hydrodynamic instabilities. The small cloud sizes imply that even state-of-the-art cosmological simulations require more than a 1000-fold improvement in mass resolution to resolve the hydrodynamics relevant for cool gas in the CGM
On the kinematics of cold, metal-enriched galactic fountain flows in nearby star-forming falaxies
Galaxie
The bimodal absorption system imaging campaign (BASIC). I. A dual population of low-metallicity absorbers at z < 1
Instrumentatio
The cosmic ultraviolet baryon survey (CUBS): II. Discovery of an H-bearing DLA in the vicinity of an early-type galaxy at z = 0.576
Interstellar matter and star formatio
Baryons: What, When and Where?
We review the current state of empirical knowledge of the total budget of
baryonic matter in the Universe as observed since the epoch of reionization.
Our summary examines on three milestone redshifts since the reionization of H
in the IGM, z = 3, 1, and 0, with emphasis on the endpoints. We review the
observational techniques used to discover and characterize the phases of
baryons. In the spirit of the meeting, the level is aimed at a diverse and
non-expert audience and additional attention is given to describe how space
missions expected to launch within the next decade will impact this scientific
field.Comment: Proceedings Review for "Astrophysics in the Next Decade: JWST and
Concurrent Facilities", ed. X. Tielens, 38 pages, 10 color figures. Revised
to address comments from the communit
On the kinematics of cold, metal-enriched galactic fountain flows in nearby star-forming falaxies
Galaxie