research and opportunities
I am an observational astrophysicist, with interests in active galactic nuclei, galaxy evolution, large-scale structure of the Universe, the cosmic X-ray background, and X-ray binary stars. My work uses data from the Chandra, XMM-Newton, Hubble, Spitzer, Herschel, and WISE space telescopes as well as ground-based optical, infrared, and radio observations.
I joined the Department of Physics and Astronomy at Dartmouth College as an Assistant Professor in December 2011. My research is generously funded by the NSF, NASA, and an Alfred P. Sloan Research Fellowship, and for 2014-15 I will be the Dartmouth Class of 1962 Faculty Fellow. My full CV is here. I am looking for interested and motivated students to take part in an exciting research program.
Current research group members:
black holes, dark matter halos, and the
evolution of galaxies
Much of our research focuses on the interplay between the growth of galaxies, their parent dark matter halos, and the central supermassive black holes. A remarkable success in astrophysics in the past decade has been the emergence of a physical framework for how galaxies form and evolve over the history of the Universe. Our work explores some interesting and perhaps unexpected elements of this picture: how the gravitational potential of the dark matter halos that surround galaxies, as well as the energy released by growing supermassive black holes at their centers, can profoundly influence the physical state of interstellar gas and the formation of stars. We are just starting to explore these processes in detail with observations, thanks to powerful new telescopes and multiwavelength surveys.
For an extensive review of black hole and galaxy evolution research motivated by the workshop in Durham on What Drives the Growth of Black Holes?, see our review article (Alexander & Hickox 2012) to appear in New Astronomy Reviews.
For a brief overview of this field geared toward a more general audience, see Supermassive Black Holes and the Growth of Galaxies, which appeared in the UK magazine The Astronomer in March/April 2011.
Click here for more details on the research program and links to publications.
AGN vs. Star Formation: The Fate of the Gas in Galaxies
My group co-organized an international
workshop on the relationship between AGN activity and star
formation in galaxies. The workshop was held in Durham, United
Kingdom from 28 July to 1 August 2014. Information on the workshop
is available at the workshop website. The
workshop was a collaboration between Dartmouth and Durham University as part of the Matariki Network of
Black Hole Feedback 2012
In summer 2012 we hosted an international
workshop on AGN titled "Black Hole Feedback 2012: What is the role
of AGN in the evolution of galaxies?", along with colleagues at
Durham as part of the Matariki Network. The workshop was held at
Dartmouth from 30 July to 3 August 2012. Information on the
workshop, including talk videos and slides, is available at the workshop
CDFS stacked rest-frame spectra
As part of a Chandra archive data analysis program (SP8-9001), we have extracted rest-frame X-ray spectra for all sources with robust spectroscopic redshifts in the 4 Ms Chandra Deep Field South. For publicly available cleaned event files and spectra click here.