Deceleration of CIV and SiIV broad absorption lines in X-ray bright quasar SDSS-J092345+512710

TL;DR

This study reports a synchronized deceleration of CIV and SiIV broad absorption lines in a high-ionization, X-ray bright quasar, indicating dynamic changes in the quasar's disk wind over several years.

Contribution

First observation of synchronized deceleration in multiple BALs in an X-ray bright quasar, suggesting evolving disk wind parameters without continuum variability.

Findings

Deceleration rates of -1.62 and -1.14 cm/s^2 for CIV and SiIV BALs.

No acceleration observed in the red component.

Variability likely due to changes in disk wind parameters.

Abstract

We report a synchronized kinematic shift of CIV and SiIV broad absorption lines (BAL) in a high-ionization, radio-loud, and X-ray bright quasar SDSS-J092345+512710 (at $z_{em} \sim 2.1627$). This quasar shows two broad absorption components (blue component at $v \sim 14,000\ km\ s^{-1}$, and red component at $v \sim 4,000\ km\ s^{-1}$ with respect to the quasars systemic redshift). The absorption profiles of CIV and SiIV BAL of the blue component show decrease in outflow velocity with an average deceleration rate of $-1.62_{-0.05}^{+0.04}\ cm\ s^{-2}$ and $-1.14^{+0.21}_{-0.22}\ cm\ s^{-2}$ over a rest-frame time-span of 4.15 yr. We do not see any acceleration-like signature in the red component. This is consistent with dramatic variabilities usually seen at high velocities. During our monitoring period the quasar has shown no strong continuum variability. We suggest the observed variability could be related to the time dependent changes in disk wind parameters like launching radius, initial flow velocity or mass outflow rate.