Ca II and Na i quasar absorption-line systems in an emission-selected sample of SDSS DR7 galaxy/quasar projections. I. Sample selection

  • Cherinka B
  • Schulte-Ladbeck R
  • 11


    Mendeley users who have this article in their library.
  • 3


    Citations of this article.


The aim of this project is to identify low-redshift host galaxies of quasar absorption-line systems by selecting galaxies that are seen in projection onto quasar sightlines. To this end, we use the Seventh Data Release of the Sloan Digital Sky Survey to construct a parent sample of 97,489 galaxy/quasar projections at impact parameters of up to 100 kpc to the foreground galaxy. We then search the quasar spectra for absorption-line systems of Ca II and Na I within ±500 km s–1 of the galaxy's velocity. This yields 92 Ca II and 16 Na I absorption systems. We find that most of the Ca II and Na I systems are sightlines through the Galactic disk, through high-velocity cloud complexes in our halo, or Virgo Cluster sightlines. Placing constraints on the absorption line rest equivalent width significance (>=3.0σ), the local standard of rest velocity along the sightline (>=345 km s–1), and the ratio of the impact parameter to the galaxy optical radius (

Author-supplied keywords

  • catalogs
  • galaxies: general
  • quasars: absorption lines
  • quasars: individual (Ca ii, Nai)

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • B. Cherinka

  • R. E. Schulte-Ladbeck

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free