Constraining the Properties of the Multiphase Absorption System at z = 0.93 towards PG1206+459
Open Access
Author:
Rosenwasser, Benjamin Edward
Area of Honors:
Astronomy and Astrophysics
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Jane Camilla Charlton, Thesis Supervisor Jane Camilla Charlton, Thesis Honors Advisor Steinn Sigurdsson, Faculty Reader
Keywords:
galaxy evolution circumgalactic medium quasar absorption line spectroscopy
Abstract:
The results of photoionization and collisional ionization modeling are presented of the strong MgII absorption system at redshift z ≈ 0.93 towards the quasar PG1206+459. A combination of spectra from Keck/HIRES, HST/FOS, HST/STIS, and the recent observations of OVI from HST/COS are used in the analysis. This system has been extensively studied over the last two decades (Churchill & Charlton 1999; Ding et al. 2003; Tripp et al. 2011), and updated constraints using the recent data are presented. Numerous absorption components are spread over a range of ~1500 km/s, and multiple ionization phases are required to account for the detected transitions, which include MgI, MgII, FeII, SiII, SiIII, SiIV, CII, CIII, CIV, SIII, SIV, SV, SVI, NIII, NIV, NV, OIII, OIV, OV, OVI, and NeVIII. Considering the new constraints, the question of the physical nature of the absorption system is revisited, which in the past has been interpreted as arising in a group of galaxies or a post-starburst outflow from a single galaxy.
