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Column density profiles of multiphase gaseous haloes

Liang, Cameron J. ; Kravtsov, Andrey V. and Agertz, Oscar LU (2016) In Monthly Notices of the Royal Astronomical Society 458(2). p.1164-1187
Abstract

We analyse circumgalactic medium (CGM) in a suite of high-resolution cosmological re-simulations of a Milky Way size galaxy and show that CGM properties are quite sensitive to details of star formation-feedback loop modelling. The simulation that produces a realistic late-type galaxy, fails to reproduce existing observations of the CGM. In contrast, simulation that does not produce a realistic galaxy has the predicted CGM in better agreement with observations. This illustrates that properties of galaxies and properties of their CGM provide strong complementary constraints on the processes governing galaxy formation. Our simulations predict that column density profiles of ions are well described by an exponential function of projected... (More)

We analyse circumgalactic medium (CGM) in a suite of high-resolution cosmological re-simulations of a Milky Way size galaxy and show that CGM properties are quite sensitive to details of star formation-feedback loop modelling. The simulation that produces a realistic late-type galaxy, fails to reproduce existing observations of the CGM. In contrast, simulation that does not produce a realistic galaxy has the predicted CGM in better agreement with observations. This illustrates that properties of galaxies and properties of their CGM provide strong complementary constraints on the processes governing galaxy formation. Our simulations predict that column density profiles of ions are well described by an exponential function of projected distance d: N ∝r e-d/hs
. Simulations thus indicate that the sharp drop in absorber detections at larger distances in observations does not correspond to a 'boundary' of an ion, but reflects the underlying steep exponential column density profile. Furthermore, we find that ionization energy of ions is tightly correlated with the scaleheight hs: hs ∝ Eion
0.74. At z ≈ 0, warm gas traced by low-ionization species (e.g. Mg ii and C iv) has hs ≈ 0.03 - 0.07Rvir, while higher ionization species (O vi and Ne viii) have hs ≈ 0.32 - 0.45Rvir. Finally, the scaleheights of ions in our simulations evolve slower than the virial radius for z ≤ 2, but similarly to the halo scale radius, rs. Thus, we suggest that the column density profiles of galaxies at different redshifts should be scaled by rs rather than the halo virial radius.

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author
; and
publishing date
type
Contribution to journal
publication status
published
keywords
Cosmology: Theory, Galaxies: Evolution, Galaxies: Formation, Galaxies: Haloes
in
Monthly Notices of the Royal Astronomical Society
volume
458
issue
2
pages
24 pages
publisher
Oxford University Press
external identifiers
  • scopus:84963859658
ISSN
0035-8711
DOI
10.1093/mnras/stw375
language
English
LU publication?
no
id
1ee53886-43d9-41d3-8eae-82e29a163abd
date added to LUP
2019-02-07 11:15:01
date last changed
2022-03-02 19:55:40
@article{1ee53886-43d9-41d3-8eae-82e29a163abd,
  abstract     = {{<p>We analyse circumgalactic medium (CGM) in a suite of high-resolution cosmological re-simulations of a Milky Way size galaxy and show that CGM properties are quite sensitive to details of star formation-feedback loop modelling. The simulation that produces a realistic late-type galaxy, fails to reproduce existing observations of the CGM. In contrast, simulation that does not produce a realistic galaxy has the predicted CGM in better agreement with observations. This illustrates that properties of galaxies and properties of their CGM provide strong complementary constraints on the processes governing galaxy formation. Our simulations predict that column density profiles of ions are well described by an exponential function of projected distance d: N ∝r e<sup>-d/h<sub>s</sub><br>
                            </sup>. Simulations thus indicate that the sharp drop in absorber detections at larger distances in observations does not correspond to a 'boundary' of an ion, but reflects the underlying steep exponential column density profile. Furthermore, we find that ionization energy of ions is tightly correlated with the scaleheight h<sub>s</sub>: h<sub>s</sub> ∝ E<sub>ion</sub><br>
                            <sup>0.74</sup>. At z ≈ 0, warm gas traced by low-ionization species (e.g. Mg ii and C iv) has h<sub>s</sub> ≈ 0.03 - 0.07R<sub>vir</sub>, while higher ionization species (O vi and Ne viii) have h<sub>s</sub> ≈ 0.32 - 0.45R<sub>vir</sub>. Finally, the scaleheights of ions in our simulations evolve slower than the virial radius for z ≤ 2, but similarly to the halo scale radius, r<sub>s</sub>. Thus, we suggest that the column density profiles of galaxies at different redshifts should be scaled by r<sub>s</sub> rather than the halo virial radius.</p>}},
  author       = {{Liang, Cameron J. and Kravtsov, Andrey V. and Agertz, Oscar}},
  issn         = {{0035-8711}},
  keywords     = {{Cosmology: Theory; Galaxies: Evolution; Galaxies: Formation; Galaxies: Haloes}},
  language     = {{eng}},
  month        = {{03}},
  number       = {{2}},
  pages        = {{1164--1187}},
  publisher    = {{Oxford University Press}},
  series       = {{Monthly Notices of the Royal Astronomical Society}},
  title        = {{Column density profiles of multiphase gaseous haloes}},
  url          = {{http://dx.doi.org/10.1093/mnras/stw375}},
  doi          = {{10.1093/mnras/stw375}},
  volume       = {{458}},
  year         = {{2016}},
}