Acceleration of a C <scp>iv</scp> broad absorption line in Quasar SDSS J140006.88+412142.5

ABSTRACT We undertake a comprehensive analysis of the absorption lines in the quasar J140006.88+412142.5, employing spectroscopic data spanning three epochs from the SDSS DR16. These spectral observations unveil the presence of two extensive absorption systems (designated as systems A and B) in both C iv and Si iv, each system composed of multiple sub-components (systems A1, A2, A3, B1, and B2) exhibiting unique characteristics. Our results highlight significant variations in the equivalent widths across all broad absorption lines (BALs), which are most convincingly attributed to variations in ionization states resulting from fluctuations in the continuum. Furthermore, our analysis suggests that system A is in a state of higher ionization compared to system B. A second pivotal discovery of this study is the velocity shift observed in the C iv BAL of system A1. This shift can plausibly be ascribed to an actual acceleration of the outflow material, driven by the enhance of radiation pressure from the background light source.