Strong MgII absorber blazars Virtual Observatory Resource

Authors
  1. Mishra S.
  2. Chand H.
  3. Gopal-Krishna
  4. Joshi R.
  5. Shchekinov Y.A.,Fatkhullin T.A.
  6. Published by
    CDS
Abstract

It is widely believed that the cool gas clouds traced by MgII absorption, within a velocity offset of 5000km/s relative to the background quasar are mostly associated with the quasar itself, whereas the absorbers seen at larger velocity offsets towards us are intervening absorber systems and hence their existence is completely independent of the background quasar. Recent evidence by Bergeron et al. (2011A&A...525A..61P, hereinafter BBM) has seriously questioned this paradigm, by showing that the number density of intervening MgII absorbers towards the 45 blazars in their sample is nearly two times the expectation based on the MgII absorption systems seen towards normal quasars (QSOs). Given its serious implications, it becomes important to revisit this finding, by enlarging the blazar sample and subjecting it to an independent analysis. Here, we first report the outcome of our re-analysis of the available spectroscopic data for the BBM sample itself. Our analysis of the BBM sample reproduces their claimed factor of 2 excess of dN/dz along blazar sightlines, vis-a-vis normal QSOs. We have also assembled an approximately three times larger sample of blazars, albeit with moderately sensitive optical spectra. Using this sample together with the BBM sample, our analysis shows that the dN/dz of the MgII absorbers statistically matches that known for normal QSO sightlines. Further, the analysis indicates that associated absorbers might be contributing significantly to the estimated dN/dz up to offset speeds {DELTA}v~0.2c relative to the blazar.

Keywords
  1. active-galactic-nuclei
  2. bl-lacertae-objects
  3. quasars
  4. redshifted
  5. line-intensities
Bibliographic source Bibcode
2018MNRAS.473.5154M
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/473/5154
IVOA Identifier IVOID
ivo://CDS.VizieR/J/MNRAS/473/5154

Access

Web browser access HTML
http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/473/5154
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/473/5154
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/473/5154
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/473/5154/table2?
https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/473/5154/table2?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/473/5154/table2?

History

2021-02-10T15:43:01Z
Resource record created
2021-02-10T15:43:01Z
Created
2021-10-05T13:12:36Z
Updated

Contact

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