Hubble Fellow @ MIT
Speaking at 2013 Hubble Fellows Symposium at STScI (Mar, 5, 2013)
Recently published ApJ letter presenting HST imaging of the Phoenix Cluster here! (Feb 2013)
mcdonald "at" space.mit.edu
![]() Composite image of the filamentary complex in Abell 1795. (Yellow: Red continuum, old stellar populations; Red: MMTF Hα, warm ionized gas; Blue: HST far-UV, young stellar populations). This complex multiphase system is most likely the result of runaway cooling in the hot, intracluster plasma. |
My current research is focused on understanding heating and cooling processes in the cores of galaxy clusters. By necessity, this work requires use of a wide variety of data, including X-ray, UV, optical, IR, sub-mm, and radio observations. In collaboration with the South Pole Telescope (SPT) team, I am trying to understand the evolution of a sample of massive, SZ-selected galaxy clusters. This nearly redshift independent sample is proving to be invaluable for studying the evolution of the hot, intracluster medium.
For my PhD thesis, I used the Maryland-Magellan Tunable Filter to examine heating and cooling processes in galaxy groups and clusters, primarily by looking for extended Hα emission. The exquisite resolution (DIQ ~ 0.5") of these data allows us to resolve structure which was previously unknown, such as the intertwined filaments in Abell 1795 (left). By combining the emission-line data with existing Chandra and GALEX observations, as well as new HST observations in the far-UV, we shed new light on these mysterious structures. For our results, see my publications. |
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The "Markarian Chain" in the Virgo Cluster |
For my MSc. thesis,
I conducted a near-IR (H-band) survey of the Virgo cluster with
Stephane Courteau (Queen's University) and Brent Tully (University of
Hawaii). We obtained optical and H-band photometry for a complete sample
of 293 Virgo cluster galaxies which we used to perform a detailed
analysis on the structural properties of these galaxies via bulge-disk
decompositions.
The exciting results of this extensive study have been accepted for publication in MNRAS. |
See my latest publications and conference proceedings here.