Research Overview

One of my main research goals is to understand the physical mechanism by which all supermassive black holes at the centers of galaxies grow, as well as to investigate the interplay between black hole growth, in the form of Active Galactic Nuclei, and the properties of their host galaxies. In particular, I study how the first black holes in the Universe grew from their initial seeds; how known relations between black holes and their galaxies become established; are black holes hidden from our view by the same material that makes them grow? If so, how did this fuel arrive at the black hole, and what is its geometric configuration - does this affect the rate at which the black hole grows? What was the trigger for the growth of the black hole; and are growing black holes preferentially hosted in particular galaxy types?

In 2010, I received my PhD from the University of Durham under the supervision of Prof. David Alexander on a Census of AGN Activity in the nearby Universe. In 2010-14, I was at the Harvard-Smithsonian Center for Astrophysics as a Smithsonian Post-doctoral Fellow. During this time, I also took up the role as a Senior Teaching Fellow at Harvard University, teaching AM207: Stochastic Optimization for two years (2013-2014). In 2014, I moved to the Department of Astrophysical Sciences at Princeton University where I am now a permanent Research Astronomer.

My research makes use of cutting-edge multi-wavelength survey data from a variety of ground-based and space-based telescopes, including the James Webb Space Telescope and Subaru Hyper Suprime-Cam instrument. I'm an active member of the UNCOVER survey, the HSC-Strategic Survey Program, the Prime Focus Spectrograph Survey, the MASSIVE collaboration, as well as various X-ray survey teams.

My immediate research includes:

  • UNCOVERing the first black holes in the Universe
  • Identifying the AGN to host-galaxy connection — what causes an AGN to grow within a particular galaxy?
  • The identification of the most heavily obscured and Compton-thick AGNs near and far
  • The demography of AGN host galaxies in deep and wide-field surveys
  • Connections between parent dark matter halos, galaxy properties, and the rapid growth of super-massive black holes.
  • Understanding the nature of optically unidentified AGNs within dust/gas rich late-type galaxies within the local Universe.
  • The relation between multi-wavelength high-ionization emission features and the intrinsic properties of AGN

Census of AGN Activity I:
Optically-elusive AGN


Census of AGN Activity II:
Growth of nearby Black Holes


Mid-IR Compton-thick AGN:
AGN space density at z=0.1


X-ray sources in the DEEP2 fields


Si-absorption in CTAGN:
Host galaxy extinction


AGN-Galaxy Connection:
Evolution of AGN host galaxies


Departmental and Teaching Activities

In the Astrophysical Sciences department at Princeton University, I chair the department's observing program using the Magellan Baade/Clay and WIYN telescopes, I mentor several of our graduate students for their semester projects and PhD theses, and I am the former director of the Undergraduate Summer Research Program (USRP). Our USRP welcomes promising young undergraduates to conduct cutting-edge research alongside members of our department. During the summer months, the students are also taught fundamental and essential skills that are readily used by astronomers and other scientists during their time as researchers.

During the 2012 and 2013 academic years, I was a Senior Teaching Fellow at Harvard University for the course "AM207: Advanced Computional science: Stochastic Optimization Methods". My specific areas of expertise revolve around teaching sections on scripted coding in the MATLAB and Python environments; Bayesian inference and prior definitions; Optimization methods using simulated annealing and genetic algorithms; MC EM algorithms. I use many of these statistical techniques and analysis methodologies throughout my research. Furthermore, I graded and held office hours for AM207 on a weekly basis in the Spring Academic semester.