Comprehensive Connection among the Quasars with Different Types of Outflow Absorption Lines

Abstract

It is commonly accepted that outflows from the central regions of quasars play a substantial role in regulating the global properties of the host galaxy. These outflows are typically detected through blueshifted absorption lines. However, the question remains whether outflows observed with different absorption line types indeed reflect the same environmental or evolutionary stage of the host galaxy. In this study, we use the Sloan Digital Sky Survey quasar catalog and employ the flux ratio of [O II ] and [Ne V] emission lines as indicators to compare star formation rates (SFRs) within host galaxies of quasars exhibiting various outflow absorption line types: low-ionization broad absorption line (LoBAL), low-ionization Mini-BAL (LoMini-BAL), low-ionization narrow absorption line (LoNAL), high-ionization broad absorption line (HiBAL), high-ionization Mini-BAL (HiMini-BAL), and high-ionization narrow absorption line (HiNAL). Our findings indicate that the SFR of LoMini-BAL quasars is comparable to that of LoNAL quasars, somewhat less than that of LoBAL quasars, but markedly greater than that of HiBAL quasars. Furthermore, the SFR of HiMini-BAL quasars mirrors that of HiNAL or Non-abs (no associated absorption lines) quasars, but is significantly higher than that of HiBAL quasars. If we consider that differing absorption line types are indicative of the quasar evolution stage, our results propose an inclusive evolution sequence: LoBALs evolve into LoMini-BALs/LoNALs, then progress to HiBALs, and ultimately morph into HiMini-BALs/HiNALs/Non-abs. Concomitantly, the SFR within the host galaxies of quasars appears to decline noticeably nearing the LoNAL phase’s end and rejuvenates before the HiMini-BAL phase.

Keywords

• Quasar absorption line spectroscopy
• Active galaxies