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Peter Craig

Dr. Peter Craig's Research Interests

First off, here is a link to my publication list, hosted as a Nasa ADS Library page

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Galactic Dynamics

Most of my Ph.D. research was focused on Galactic dynamics, with a particular focus on measuring the potential of the Milky Way (MW). Our aim was generally to find novel approaches to measuring the potential, usually trying to use new forms of information that haven't been adapted for this previously. These checks often entail some caveats and uncertainties, but have the benefit of being independent of typical measurement techniques. In some cases, these methodologies have considerable potential for improving our Galactic mass estimates in the future, as new data sets become available.

One project to do this used hydrodynamical simulations of the Magellanic Stream (MS), the formation of which is sensitive to the assumed Galactic potential. Varying the assumed potential properties in our simulations produces different properties of the derived stream, especially the length. After producing a series of simulations with different masses for the MW, a straightforward linear relationship appears between the MW mass and the length of the simulated stream. Based on real observations of the stream, we can estimate the true stream length, and use that as an estimator of the MW mass. While there remains considerable uncertainty in the result here, it is a novel method that produces a very reasonable estimate for the MW mass, consistent with several other mass estimators. A video of one of these simulations is shown below, displaying the two Magellanic clouds falling into the gravitational potential of the MW, and interacting with diffuse gas surrounding the MW.

If you're interested in more details, feel free to check out the paper here.

Strongly Lensed Supernovae

Below is a figure showing difference imaging based detection of a solar system body. This source was discovered during our survey searching for supernovae in strongly lensed galaxies. The top row of images show our difference images, and the original data frames are on the bottom row. These are three consecutive 5 minute exposures, and we see the object move from one frame to the next.

Images of SSB discovered during Supernova search