Absorption in multiphase circumgalactic medium Virtual Observatory Resource

Authors
  1. Liang C.J.
  2. Chen H.-W.
  3. Published by
    CDS
Abstract

This paper presents an absorption-line study of the multiphase circumgalactic medium (CGM) based on observations of Ly{alpha}, CII, CIV, SiII, SiIII, and SiIV absorption transitions in the vicinities of 195 galaxies at redshift z<0.176. The galaxy sample is established based on a cross-comparison between public galaxy and quasi-stellar object (QSO) survey data and is characterized by a median redshift of <z>=0.041, a median projected distance of <d>=362kpc to the sightline of the background QSO, and a median stellar mass of log(M_star_/M_{sun}_)=9.7+/-1.1. Comparing the absorber features identified in the QSO spectra with known galaxy properties has led to strong constraints for the CGM absorption properties at z<~0.176. First, abundant hydrogen gas is observed out to d~500kpc, well beyond the dark matter halo radius R_h_ of individual galaxies, with a mean covering fraction of ~60 percent. In contrast, no heavy elements are detected at d>~0.7R_h_ from either low-mass dwarfs or high-mass galaxies. The lack of detected heavy elements in low- and high-ionization states suggests that either there exists a chemical enrichment edge at d~0.7R_h_ or gaseous clumps giving rise to the observed absorption lines cannot survive at these large distances. Considering all galaxies at d>R_h_ leads to a strict upper limit for the covering fraction of heavy elements of ~3% (at a 95% confidence level) over d=(1-9)R_h_. At d<R_h_, differential covering fraction between low- and high-ionization gas is observed, suggesting that the CGM becomes progressively more ionized from d<0.3R_h_ to larger distances. Comparing CGM absorption observations at low and high redshifts shows that at a fixed fraction of R_h_ the CGM exhibits stronger mean absorption at z=2.2 than at z~0, and that the distinction is most pronounced in low-ionization species traced by CII and SiII absorption lines. We discuss possible pseudo-evolution of the CGM as a result of misrepresentation of halo radius, and present a brief discussion on the implications of these findings.

Keywords
  1. quasars
  2. galaxies
  3. line-intensities
Bibliographic source Bibcode
2014MNRAS.445.2061L
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/445/2061
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/445/2061
Document Object Identifer DOI
doi:10.26093/cds/vizier.74452061

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/445/2061
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/445/2061
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/445/2061
IVOA Table Access TAP
http://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/445/2061/galaxies?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/445/2061/galaxies?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/445/2061/galaxies?
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/445/2061/table2?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/445/2061/table2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/445/2061/table2?

History

2015-10-09T15:49:03Z
Resource record created
2015-10-09T15:49:03Z
Created
2024-08-14T20:18:17Z
Updated

Contact

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CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr