Probing the Assembly of Dwarf Galaxies through Cosmic Time with Damped Lyα Absorption Spectroscopy

We investigate the absorption features associated with a gas-rich dwarf galaxy, using cosmological hydrodynamics simulations. Our goal is to explore whether the progenitors of the lowest-mass dwarf galaxies known to harbor neutral hydrogen today ( , ) could possibly be detected as Damped Ly α Absorb...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2019-06, Vol.878 (2), p.98
Main Authors: Jeon, Myoungwon, Besla, Gurtina, Bromm, Volker
Format: Article
Language:English
Subjects:
Absorption
Absorption spectroscopy
Astrophysics
Dwarf galaxies
Evolution
Fluid dynamics
Fluid flow
Galactic evolution
Hydrodynamics
Hydrogen
Neutral gases
Population III stars
Radiation
Simulation
Spectroscopy
Stars & galaxies
Stellar evolution
Stellar populations
Ultraviolet radiation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigate the absorption features associated with a gas-rich dwarf galaxy, using cosmological hydrodynamics simulations. Our goal is to explore whether the progenitors of the lowest-mass dwarf galaxies known to harbor neutral hydrogen today ( , ) could possibly be detected as Damped Ly α Absorbers (DLAs) over cosmic time. We trace the evolution of a single dwarf galaxy, preselected to contain DLAs, from the era of the first metal-free, so-called Population III (Pop III) stars, down to z  = 0, thus allowing us to study the metal enrichment history of DLAs associated with the simulated galaxy. We find that the progenitors of the simulated dwarf are expected to be seen for most of their evolution as DLAs that are contaminated by normal, Population II stars. The time period during which DLAs are only metal-enriched by Pop III stars, on the other hand, is likely very brief, confined to high redshifts, z  ≳ 6. The susceptibility of the dwarfs to the external UV radiation background allows them to preserve neutral gas only at the center (a few ∼100 pc). This results in a small probability that the simulated dwarf would be observed as a DLA. This study suggests that DLAs are unlikely to be hosted in the lowest-mass dwarfs that can harbor neutral gas ( ), below which neutral gas is unlikely to exist. However, this study does illustrate that, when detected, absorption lines provide a powerful method for probing ISM conditions inside the smallest dwarf galaxies at intermediate to high redshifts.
ISSN:0004-637X
1538-4357
DOI:10.3847/1538-4357/ab1eaa