A variable P舁v broad absorption line and quasar outflow energetics

Abstract

Broad absorption lines (BALs) in quasar spectra identify high velocity outflows that might exist in all quasars and could play a major role in feedback to galaxy evolution. The viability of BAL outflows as a feedback mechanism depends on their kinetic energies, as derived from the outflow velocities, column densities, and distances from the central quasar. We estimate these quantities for the quasar, Q1413+1143 (redshift z e = 2.56), aided by the first detection of P v λ1118, 1128 BAL variability in a quasar. In particular, P v absorption at velocities where the C iv trough does not reach zero intensity implies that the C iv BAL is saturated and the absorber only partially covers the background continuum source (with characteristic size <0.01 pc). With the assumption of solar abundances, we estimate that the total column density in the BAL outflow is log N H 22.3 cm −2 . Variability in the P v and saturated C iv BALs strongly disfavors changes in the ionization as the cause of the BAL variability, but supports models with high-column density BAL clouds moving across our lines of sight. The observed variability time of 1.6 yr in the quasar rest frame indicates crossing speeds >750 km s −1 and a radial distance from the central black hole of 3.5 pc, if the crossing speeds are Keplerian. The total outflow mass is ∼4100 M ⊙ , the kinetic energy ∼4 × 10 54 erg, and the ratio of the outflow kinetic energy luminosity to the quasar bolometric luminosity is ∼0.02 (at the minimum column density and maximum distance), which might be sufficient for important feedback to the quasar's host galaxy.

Evidence for two spatially separated UV continuum emitting regions in the Cloverleaf broad absorption line quasar

“…One explaining the variability as caused by rapid crossing of an absorbing cloud, and one as a rapid change of ionization in the ionized material (e.g., Lundgren et al 2007;Filiz Ak et al 2012;Capellupo et al 2013;Wildy & Goad 2015;Grier et al 2015). Recently, Capellupo et al (2014) carried out a detailed study of the variability of the A1-A2 absorbers in H1413+117.…”

Evidence for Photoionization-Driven Broad Absorption Line Variability

“…In contrast, Wildy et al (2014) claimed that BAL variations were not correlated with continuum variations, casting doubt on this interpretation. In addition, Capellupo et al (2014) found variable P V absorption lines associated with non-black C IV absorption lines, which they interpreted as ionized gas moving across the continuum source. There is also an argument that the ionizing continuum may vary in a different way from the observed UV continuum due to changes in a presumed high ionization shielding gas (Filiz Ak et al 2012).…”

Far-infrared emission in luminous quasars accompanied by nuclear outflows

“…The numbers are small, but it does indicate that BALQSOs are at least as likely to be FIR-luminous as nonBALQSOs, and possibly even more likely, in contrast to the result from Cao Orjales et al (2012). In special circumstances, the distance to the absorbing material, and thus the mass of the material and energy of the outflow, can be estimated, and it is found that the energy contained within the outflow is sufficient to have an effect on galaxy scales (Moe et al 2009, Capellupo, Hamann, & Barlow 2014. The outflows with distance estimates put the absorbing material at kiloparsec-scale distances, far beyond the immediate black hole neighbourhood, consistent with the radial extent found within simulations.…”

“…Similar outflows can also be observed in X-rays (Reeves, O'Brien, & Ward 2003, Reeves et al 2009). The energy injected, and ultimately the effect on the BALQSO host galaxy, is difficult to determine, except under special circumstances (Moe et al 2009, Dunn et al 2010, Capellupo, Hamann, & Barlow 2014.…”