Advanced

The nature of damped HI absorbers probed by cosmological simulations: satellite accretion and outflows

Pehlivan Rhodin, Nils Henrik ; Agertz, Oscar LU ; Christensen, Lise ; Renaud, Florent LU and Uldall Fynbo, Johan Peter (2019) In Monthly Notices of the Royal Astronomical Society p.3634-3634
Abstract
We use cosmological hydrodynamic zoom simulations to study the neutral gas distributionin and around galaxies that gives rise to high column density HILyαabsorption (dampedLyαsystems (DLAs) and sub-DLAs) in background quasar spectra. Such simulations oftensacrifice numerical resolution for volume that affects the lower density galaxy halo gas,and simulations have difficulties reproducing the span of projected separations (b) betweenabsorbing clouds and their hosts. Our simulations produce (sub-)DLAs over the entire probedparameter space (b50 kpc and metallicity−4[M/H]0.5) at all redshifts (z∼0.4−3.0),enclosing spectroscopically confirmed absorber-galaxy pairs. Recovering (sub-)DLAs atb20−30 kpc from a massive host galaxy ... (More)
We use cosmological hydrodynamic zoom simulations to study the neutral gas distributionin and around galaxies that gives rise to high column density HILyαabsorption (dampedLyαsystems (DLAs) and sub-DLAs) in background quasar spectra. Such simulations oftensacrifice numerical resolution for volume that affects the lower density galaxy halo gas,and simulations have difficulties reproducing the span of projected separations (b) betweenabsorbing clouds and their hosts. Our simulations produce (sub-)DLAs over the entire probedparameter space (b50 kpc and metallicity−4[M/H]0.5) at all redshifts (z∼0.4−3.0),enclosing spectroscopically confirmed absorber-galaxy pairs. Recovering (sub-)DLAs atb20−30 kpc from a massive host galaxy requires high numerical resolution and efficientfeedback, and we show that these lines-of-sight are associated with dwarf satellites in the mainhalo, stripped metal-rich gas, and outflows. HIdisc- and halo gas significantly contributesto (sub-)DLAs around galaxies. At large redshifts the halo plays an increasingly importantrole, while at 0.4<z<1 the disc and halo contribute with∼60(80) and∼40(20) per centto column densities above the sub-DLA(DLA) lower limits. The distribution ofbfor sub-DLAs and DLAs overlap atz∼2−3, but evolves so that sub-DLAs on average are locatedat twice largerbbyz∼0.5. A weak correlation suggests that sub-DLA covering fractionsincrease with stellar mass more rapidly than those of DLA. This can explain why sub-DLAsare preferentially selected in more massive galaxies in the low-zUniverse. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Astrophysics - Astrophysics of Galaxies
in
Monthly Notices of the Royal Astronomical Society
pages
3645 pages
publisher
Oxford University Press
ISSN
0035-8711
DOI
10.1093/mnras/stz1479
language
Unknown
LU publication?
yes
id
6ff5ea72-4db1-48c4-ba69-cc08a5f09319
date added to LUP
2019-05-21 15:16:19
date last changed
2020-01-14 11:40:05
@article{6ff5ea72-4db1-48c4-ba69-cc08a5f09319,
  abstract     = {We use cosmological hydrodynamic zoom simulations to study the neutral gas distributionin and around galaxies that gives rise to high column density HILyαabsorption (dampedLyαsystems (DLAs) and sub-DLAs) in background quasar spectra. Such simulations oftensacrifice  numerical  resolution  for  volume  that  affects  the  lower  density  galaxy  halo  gas,and simulations have difficulties reproducing the span of projected separations (b) betweenabsorbing clouds and their hosts. Our simulations produce (sub-)DLAs over the entire probedparameter space (b50 kpc and metallicity−4[M/H]0.5) at all redshifts (z∼0.4−3.0),enclosing spectroscopically confirmed absorber-galaxy pairs. Recovering (sub-)DLAs atb20−30  kpc  from  a  massive  host  galaxy  requires  high  numerical  resolution  and  efficientfeedback, and we show that these lines-of-sight are associated with dwarf satellites in the mainhalo, stripped metal-rich gas, and outflows. HIdisc- and halo gas significantly contributesto (sub-)DLAs around galaxies. At large redshifts the halo plays an increasingly importantrole, while at 0.4&lt;z&lt;1 the disc and halo contribute with∼60(80) and∼40(20) per centto column densities above the sub-DLA(DLA) lower limits. The distribution ofbfor sub-DLAs and DLAs overlap atz∼2−3, but evolves so that sub-DLAs on average are locatedat twice largerbbyz∼0.5. A weak correlation suggests that sub-DLA covering fractionsincrease with stellar mass more rapidly than those of DLA. This can explain why sub-DLAsare preferentially selected in more massive galaxies in the low-zUniverse.},
  author       = {Pehlivan Rhodin, Nils Henrik and Agertz, Oscar and Christensen, Lise and Renaud, Florent and Uldall Fynbo, Johan Peter},
  issn         = {0035-8711},
  language     = {und},
  month        = {05},
  pages        = {3634--3634},
  publisher    = {Oxford University Press},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {The nature of damped HI absorbers probed by cosmological simulations: satellite accretion and outflows},
  url          = {http://dx.doi.org/10.1093/mnras/stz1479},
  doi          = {10.1093/mnras/stz1479},
  year         = {2019},
}