Supermassive Black Hole Growth During The Peak Of Cosmic Star Formation
- Author(s): Ross, Nathaniel Robert
- Advisor(s): Malkan, Matthew A
- et al.
Massive galaxies in the nearby universe all show evidence of a central Supermassive
Black Hole. The black holes are seen to grow over time by accretion of gas
from their host galaxy, a phenomenon referred to as an Active Galactic Nucleus.
This process is believed to be fundamental to the observed correlations between
black hole mass and properties of the host galaxies. We have a more limited and
biased understanding of the growth of supermassive black holes in more ‘typical’
galaxies at z ∼ 1 − 2. In this work, we search for Active Galactic Nuclei in a
population of star-forming galaxies spanning a mass range of M∗ ∼ 10^7−10^12 M⊙
at 0.62 < z < 2.39, during the peak of cosmic star formation and massive black
hole growth. Our data are drawn from the WFC3 Infrared Spectroscopic Parallels
(WISP) survey, for which we designed and implemented a suite of data analysis
routines for discovering and measuring star-forming galaxies and active galactic
nuclei. We find a sample of 50 active galactic nuclei, identified by their strong,
rest-frame optical, emission-line ratios. We find that growing supermassive black
holes in low-mass galaxies at z > 1 either make up a greater fraction of their
galaxies’ masses than those in massive galaxies, or perhaps emit a greater fraction
of their energy in [O III].