Research

Simulations: fitted Sersic index, n, versus intrinsic bulge-to-total luminosity ratio.

Extensive simulations show that Sersic index tracks intrinsic bulge-to-total ratio, but even n = 4 fits can host a significant disk component. Black points are inactive galaxies, blue are AGN host galaxies. (Simmons & Urry 2008)

It has become clear over the last decade or so that black holes co-evolve with the galaxies that surround them, but the details of this co-evolution have yet to be elucidated.

My primary research focus is on the connection between the growth of supermassive black holes and their host galaxies. I make extensive use of Hubble Space Telescope data, assessing correlations between host galaxy morphology and AGN activity as well as the role a growing black hole plays in regulating star formation in its host galaxy.

My thesis papers include a set of over 50,000 AGN+host galaxy simulations assessing the limits of two-dimensional image decomposition and the accuracy of recovered morphological parameters such as galaxy size, light profile, and AGN-to-host luminosity ratio.

Two example AGN+host galaxies observed with HST and separated into galaxy and central nuclear source, with SEDs.

Using HST to separate nucleus from host galaxy in multiple bands allows for fitting of the AGN SED separately from the host. (Simmons et al. 2011)

Recently, I found that moderate-luminosity z ~ 1 growing black holes are typically in a slow-growth phase, and that many of these black holes are hosted in galaxies with strong disk components, implying the black holes are not fed by major mergers.

Use the links above/below to learn more about my research, see my list of publications, download my CV, and find out what I do in my spare time.