Variability in Quasar Broad Absorption Line Outflows

TL;DR

This study monitors quasar broad absorption line variability over weeks to years to understand the structure and evolution of high-velocity outflows that influence galaxy development.

Contribution

It presents a long-term monitoring program of BAL variability, providing new insights into the physical properties of quasar outflows.

Findings

BALs show significant variability over different time scales.

Variability patterns differ between CIV and SiIV lines.

Results improve understanding of quasar outflow dynamics.

Abstract

Broad absorption lines (BALs) in quasar spectra identify high velocity outflows that likely exist in all quasars and could play a major role in feedback to galaxy evolution. Studying the variability in these BALs can help us understand the structure, evolution, and basic physical properties of these outflows. We are conducting a BAL monitoring program, which so far includes 163 spectra of 24 luminous quasars, covering time-scales from \sim 1 week to 8 years in the quasar rest-frame. We investigate changes in both the CIV {\lambda}1550 and SiIV {\lambda}1400 BALs, and we report here on some of the results from this program.