THE SLOAN DIGITAL SKY SURVEY REVERBERATION MAPPING PROJECT: RAPID C (IV) BROAD ABSORPTION LINE VARIABILITY

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GRIER C. J., Hall P. B., Brandt W. N., Trump J. R., SHEN Y., VIVEK M., ...More

ASTROPHYSICAL JOURNAL, vol.806, no.1, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 806 Issue: 1
  • Publication Date: 2015
  • Doi Number: 10.1088/0004-637x/806/1/111
  • Journal Name: ASTROPHYSICAL JOURNAL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: galaxies: active, galaxies: kinematics and dynamics, galaxies: nuclei, quasars: absorption lines, ACTIVE GALACTIC NUCLEI, X-RAY VARIABILITY, AGN FEEDBACK, BLACK-HOLES, ATOMIC DATABASE, DISK WINDS, MILKY-WAY, QUASARS, EMISSION, OUTFLOWS
  • Erciyes University Affiliated: Yes

Abstract

We report the discovery of rapid variations of a high-velocity C iv broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4σ) variability in the equivalent width (EW) of the broad (∼4000 km s-1 wide) C iv trough on rest-frame timescales as short as 1.20 days (∼29 hr), the shortest broad absorption line variability timescale yet reported. The EW varied by ∼10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability places a lower limit on the density of the absorbing gas of ne ? 3.9 × 105cm-3. The broad absorption line variability characteristics of this quasar are consistent with those observed in previous studies of quasars, indicating that such short-term variability may in fact be common and thus can be used to learn about outflow characteristics and contributions to quasar/host-galaxy feedback scenarios.

We report the discovery of rapid variations of a high-velocity C (IV) broad absorption line trough in the quasar SDSS J141007.74+541203.3. This object was intensively observed in 2014 as a part of the Sloan Digital Sky Survey Reverberation Mapping Project, during which 32 epochs of spectroscopy were obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We observe significant (>4 sigma) variability in the equivalent width (EW) of the broad (similar to 4000 km s(-1) wide) C (IV) trough on rest-frame timescales as short as 1.20 days (similar to 29 hr), the shortest broad absorption line variability timescale yet reported. The EW varied by similar to 10% on these short timescales, and by about a factor of two over the duration of the campaign. We evaluate several potential causes of the variability, concluding that the most likely cause is a rapid response to changes in the incident ionizing continuum. If the outflow is at a radius where the recombination rate is higher than the ionization rate, the timescale of variability places a lower limit on the density of the absorbing gas of n(e) greater than or similar to 3.9 x 105 cm(-3). The broad absorption line variability characteristics of this quasar are consistent with those observed in previous studies of quasars, indicating that such short-term variability may in fact be common and thus can be used to learn about outflow characteristics and contributions to quasar/host-galaxy feedback scenarios.