Resolving BAL Quasar Outflows: Outflow Cloud Properties Using Voigt Profile Fitting of Si IV and C IV Absorption Lines

Broad Absorption Line (BAL) quasars, a special class of Active Galactic Nuclei, make up about 10–20% of the quasar population and show broad blueshifted absorption features in lines such as C IV and Si IV. While these features provide direct evidence of outflows, their large widths and blending make them difficult to study in detail. A small fraction of BAL quasars show resolved Si IV absorption with distinct narrow components, offering a unique opportunity to probe the internal structure of outflowing gas. In this work, BAL quasars were selected from the DR16Q catalog, and an automated method was developed to identify sources with resolved Si IV absorption. Using the VoigtFit package, multiple Voigt components were fitted simultaneously to the Si IV and C IV absorption lines, yielding column density, Doppler parameter, and velocity offset for individual components. Unlike most previous work that examines global BAL variability, this analysis focuses on variability at the level of individual absorption components. This component-level approach enables a more detailed characterization of BAL outflows, revealing how column density, optical depth, and kinematics vary within a single outflow system, and provides direct inputs for photoionization modeling of individual kinematic components. When applied to multi-epoch data or other ions, the method tracks variability through changes in ionization, column density, or covering fraction, providing new insights into BAL outflows.