2024/02/16 by Weimin Yi, Patrick B. Hall, Yi, Weimin +12
Computer Science · Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Computational Physics and Python Applications #FOS: Physical sciences #Radio Astronomy Observations and Technology #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.2402.10444
openalex publication_date 2024/02/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present an observational study of wind acceleration based on four low-ionization broad absorption line (LoBAL) quasars (J0136, J1238, J1259, J1344). J0136 and J1344 (group-1) are radio quiet and show large BAL-velocity shifts as opposed to stable line-locking associated absorption lines (AALs). Notably, J1344 displays a linear relation between BAL-velocity shift and time interval over three consecutive epochs, characteristic of compelling evidence for BAL acceleration. J1238 and J1259 (group 2) exhibit small BAL-velocity shifts along with steep-spectrum, weak radio emission at 3.0 and 1.4 GHz. All four quasars have spectral energy distributions (SEDs) with a peak at λ\rm rest ∼10~μm, suggesting a link between the BAL acceleration and hot dust emission. The group-2 quasars are redder than group-1 quasars and have a steeper rise at 1<λ\rm rest <3~μm in their SEDs. All but J1238 exhibit a steep rise followed by a plateau-like time evolution in BAL-velocity shift. Our investigations, combined with previous studies of BAL acceleration, indicate that (1) the BAL-ISM coupling process is one of the major avenues for the origin of quasar reddening and patchy obscuration, (2) AAL outflows are ubiquitous and likely signify large-scale remnants of BAL winds coupled to interstellar medium (ISM), and (3) wind deceleration that is closely linked to the BAL-ISM coupling process may produce weak radio emission in otherwise radio-quiet quasars.