Low Ionization Gas in Galaxies: Keck HIRES Spectra of Ten QSO Absorption Systems with Ca II and Na I Lines

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

We have obtained Keck HIRES spectra of ten z < 0.1 quasar absorption systems that show Ca II λ λ 3934,3968 and/or Na I λ λ 5890,5896 absorption. The sample includes several well known QSO--galaxy pairs, and is almost complete for z < 0.1 quasar absorption systems with detected Ca II and/or Na I. These high resolution ( ~ 7 km s-1 FWHM) observations are useful for measuring the column densities and velocity widths in the multi--component absorbers. The number of velocity components varies from one in the least complex absorber to about 13 in the most complex absorber. Five of the ten systems show components with N(Na I) / N(Ca II) > 1.0, a ``high'' ratio typically interpreted, in our Galaxy, to be the result of depletion of Ca onto dust grains. These quasar absorbers also show a tendency for the narrower components to coincide with high values of N(Na I) / N(Ca II) which is also the observed tendency in the Galaxy. Several of these absorbers are probably damped Lyα (DLA) systems based on strong H I 21 cm absorption and/or H I 21 cm emission maps of the absorbing galaxies that show a high average H I column (N(H I) >= 2.0 x 1020 cm-2) at the quasar line of sight. These data are indirect evidence for dust in low z DLA systems and suggest that the dust content varies widely from component to component. Galaxies with normal morphologies and galaxies with disturbed morphologies both contribute absorbers in this sample. Gas that is ``disk--like,'' based on a high N(Na I) / N(Ca II) ratio, can be present in tidally distorted structures as well as galaxy disks.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Low Ionization Gas in Galaxies: Keck HIRES Spectra of Ten QSO Absorption Systems with Ca II and Na I Lines does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Low Ionization Gas in Galaxies: Keck HIRES Spectra of Ten QSO Absorption Systems with Ca II and Na I Lines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low Ionization Gas in Galaxies: Keck HIRES Spectra of Ten QSO Absorption Systems with Ca II and Na I Lines will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1722303

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.