An Application of Cloud-by-Cloud, Multiphase, Bayesian Modeling on System C towards Quasar PG1206+459
Open Access
Author:
You, Shengdi
Area of Honors:
Astronomy and Astrophysics
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Jane Camilla Charlton, Thesis Supervisor William Nielsen Brandt, Thesis Honors Advisor
Keywords:
quasars galaxies absorption lines
Abstract:
We apply a novel cloud-by-cloud, multiphase, Bayesian sampling method on absorption lines towards quasar PG1206+459. This method increases the efficiency at which different parameters can be tested, allowing for systems to be explored much faster compared to prior works. Previous studies of quasar PG1206+459 have designated three separate subsystems: A, B, and C. This study will focus on subsystem C. The entire system spans a velocity range from ~ -700 km/s to 900 km/s, whereas subsystem C covers the ~ 600 km/s to 900 km/s range. We present a detailed analysis of this subsystem, finding that the absorption is best explained using five clouds constrained on three transitions: MgII, CIII, and OVI, each corresponding to a separate phase (low, intermediate, and high). In the future, we will apply this method to the remaining two subsystems and provide a complete overview of the PG1206+459 system.
