research group 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 previously by an Alfred P. Sloan Research Fellowship. 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 our 2010 workshop in Durham on What Drives the Growth of Black Holes?, see our review article (Alexander & Hickox 2012) 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.
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.