Multi-epoch observations of extremely high-velocity emergent broad absorption

ROGERSON J. A., HALL P. B., HIDALGO P. R., PIRKOLA P., BRANDT W. N., Ak N.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, vol.457, no.1, pp.405-420, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 457 Issue: 1
  • Publication Date: 2016
  • Doi Number: 10.1093/mnras/stv3010
  • Journal Name: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.405-420
  • Keywords: accretion, accretion discs, quasars: absorption lines, quasars: emission lines, quasars: general, quasars: individual: SDSS J0230+0059
  • Erciyes University Affiliated: Yes

Abstract

We present the discovery of the highest velocity C IV broad absorption line to date in the z = 2.47 quasar SDSS J023011.28+005913.6, hereafter J0230. In comparing the public DR7 and DR9 spectra of J0230, we discovered an emerging broad absorption trough outflowing at similar to 60 000 km s(-1), which we refer to as trough A. In pursuing follow up observations of trough A, we discovered a second emergent CIV broad absorption trough outflowing at similar to 40 000 km s(-1), namely trough B. In total, we collected seven spectral epochs of J0230 that demonstrate emergent and rapidly (similar to 10 d in the rest-frame) varying broad absorption. We investigate two possible scenarios that could cause these rapid changes: bulk motion and ionization variability. Given our multi-epoch data, we were able to rule out some simple models of bulk motion, but have proposed two more realistic models to explain the variability of both troughs. Trough A is likely an augmented 'crossing disc' scenario with the absorber moving at 10 000 < nu(km s(-1)) < 18 000. Trough B can be explained by a flow-tube feature travelling across the emitting region at 8000 < nu(km s(-1)) < 56 000. If ionization variability is the cause for the changes observed, trough A's absorber has n(e) >= 724 cm(-3) and is at r(equal) >= 2.00 kpc, or is at r < 2.00 kpc with no constraint on the density; trough B's absorber either has n(e) >= 1540 cm(-3) and is at r(equal) >= 1.37 kpc, or is at r < 1.37 kpc with no constraint on the density.

 

We present the discovery of the highest velocity C IV broad absorption line to date in the z = 2.47 quasar SDSS J023011.28+005913.6, hereafter J0230. In comparing the public DR7 and DR9 spectra of J0230, we discovered an emerging broad absorption trough outflowing at similar to 60 000 km s(-1), which we refer to as trough A. In pursuing follow up observations of trough A, we discovered a second emergent CIV broad absorption trough outflowing at similar to 40 000 km s(-1), namely trough B. In total, we collected seven spectral epochs of J0230 that demonstrate emergent and rapidly (similar to 10 d in the rest-frame) varying broad absorption. We investigate two possible scenarios that could cause these rapid changes: bulk motion and ionization variability. Given our multi-epoch data, we were able to rule out some simple models of bulk motion, but have proposed two more realistic models to explain the variability of both troughs. Trough A is likely an augmented 'crossing disc' scenario with the absorber moving at 10 000 < nu(km s(-1)) < 18 000. Trough B can be explained by a flow-tube feature travelling across the emitting region at 8000 < nu(km s(-1)) < 56 000. If ionization variability is the cause for the changes observed, trough A's absorber has n(e) >= 724 cm(-3) and is at r(equal) >= 2.00 kpc, or is at r < 2.00 kpc with no constraint on the density; trough B's absorber either has n(e) >= 1540 cm(-3) and is at r(equal) >= 1.37 kpc, or is at r < 1.37 kpc with no constraint on the density.