PhD 3-month project
Globular clusters are fossil relics from vigorous episodes of star formation in their host systems. By studying these objects we can obtain important insights into the formation and growth of galaxies. Even within a single system, globular clusters exhibit a wide variety of different structures, ranging from extremely compact, concentrated objects to clusters which are very extended and diffuse. The structure of a globular cluster is strongly linked to both internal dynamical processes (such as two-body relaxation and mass segregation) and the influence of external forces (such as galactic tides). As such, by studying the structural properties of globular clusters in a given system, we can start to learn more about the status of their internal dynamics as well as the evolutionary history of the host.
In this 3-month project, the student will develop a code to measure the structural properties of globular clusters in the outer halo of M31 (Andromeda), the nearest large spiral galaxy to our own. Most of these globular clusters are newly discovered objects which have been uncovered as part of the Pan-Andromeda Archaeological Survey (PAndAS), which is a CFHT Large Program that has obtained survey imaging of the M31 halo, along with its satellite galaxies M33, NGC 147, and NGC 185. A wide variety of different cluster structures are evident, and it is of great interest to compare the properties of the outer halo ensemble to clusters in the inner regions of M31, as well as in the Milky Way and Local Group dwarf galaxies. Because PAndAS is a ground-based survey, and M31 globular clusters are relatively distant objects, when measuring their structures it is vital to account for the blurring effects of the earth's atmosphere. It will be possible to calibrate measurements from the student's code against observations of a few clusters taken with the Hubble Space Telescope, which suffers from no atmospheric blur.
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