Background

I have a Masters Degree in Astrophysics from the University of Edinburgh, where I studied for 6 years. My favorite areas of science are planetary formation and computer simulation, although I covered a range of projects and subjects during my time at university. Since graduating, I have been working on a small number number of science projects in my spare time, including Dark Matter studies (see Post-Masters Proposal) and simulators.

On this webpage, you can find the reports I made for all my major projects during my time at university, and my subsequent work. Don't worry if you're not a physicist, or even a scientist! I am told I have a very nice writing style that makes it very easy to follow, even when discussing complicated subjects. The title and abstract for each project is presented along with a button to download the full project report.

If you have any questions regarding these reports, or the science behind them, I am more than happy to answer. Please use the contact link at the bottom of this page!

Poster

Galaxy Shapes & Dark Matter Mapping -  2014 (Year 6)

This project aimed to perform the inaugural run of Im3shape, a galaxy shape measurement program, on real data. Nine frames of the CFHTLenS data were analysed and the results are quantified by comparing them to the results of Lensfit for the same data. Assuming the Lensfit results are true (see §4.3), multiplicative biases of 1.06004 and 1.07077 for ellipticity components 1 and 2, respectively, and additive biases of 0.00511374 and 0.00863333, respectively, were found.  It is evident from a comparison of the E and B-mode maps, however, that the significance of the Im3shape results (E-mode) are of comparable order to the B-mode map, indicating high systematic errors and rendering the Im3shape results insignificant. The possible reasons for this outcome are discussed in the report.

Understanding High Inclination and Retrograde Planets - 2013 (Year 5)

The existence of planets outwith our own solar system has been theorised for many years, and have been confirmed for over two decades [1], however the exact mechanism behind their formation has so far eluded astronomers. One of the most popular theories is the ‘Nebular’ Theory, which states that planets form from the accretion disk of protostars. However in this paper we will show that evidence from observing the Rossiter-McLaughlin effect on transiting planets suggests that the Nebular Theory is not the complete mechanism behind planetary formation. We go on to discuss the Kozai mechanism and other gravitational and tidal interactions that could cause such planetary migrations.

The Hunt For Killer Asteroids - 2013 (Year 5)

In this project, I construct a program in Visual C++ to read an asteroid ephemeris generated by the NASA JPL Horizons Ephemeris generator and compare the ephemeris points of the asteroid to the plate centres of given libraries to see if there is any chance of obtaining an image of the asteroid, possibly before it was even discovered. This is called a precovery image. If an image of an asteroid is obtained, its position will be checked against the expected position from the ephemeris, and if they do not agree, the exact difference between the actual and expected positions will be determined and attempts made to refine the orbit. Fifty-six asteroids were evaluated: a mixture of interesting objects, new discoveries and asteroids predicted to have close encounters with the Earth in the future. Only 4 asteroids were successfully imaged, and a further 7 were possibly detected, although the imaging is uncertain. All the imaged asteroids (both successful and doubtful detections) were found to agree very well with their expected positions, and no further analysis was needed. Other asteroids could not be imaged, for various reasons (detailed in Appendix B).

Computational Astrophysics Project - Direct N-Body Methods - 2013 (Year 5)

Having completed a series of 4 assignments covering several methods used in computational astrophysics, we now move on to an extended 3-week project. In this project we will further evaluate the implementation of Direct N-Body method simulators, using NBody 6, a more complicated simulator than we discussed in assignment 3. We simulated a serious of cluster at different densities with full implementation of a galactic tide, stellar evolution and an initial mass function. We then discuss how the cluster lifetime varies with the density parameter, RBar. We go on to evaluate how the total computational time of the simulation varies with RBar.

Computational Astrophysics Assignments - 2013 (Year 5)

Assignment 1 - Smoothed Particle Hydrodynamics

Assignment 2 - Grid Based Hydrodynamics

Assignment 3 - Direct N-Body Simulations

Assignment 4 - Particle Mesh Methods

Astrophysics Laboratory - Spectroscopy - 2013 (Year 4)

In this set of experiments, we first aimed to get used to the workings of our apparatus by using a prism in our spectrometer. In this stage we calculated the refractive index of the prism by finding the angle of minimum deviation, and then we focused the collimator using Schuster’s method. Since the refractive index varies with wavelength, the refractive index at a given wavelength is calculated to be nλ = -(2x10-5)λ + 1.6961. In focusing the collimator, we determined that the best focus of the collimator across all of the lines, to be a value of 5.1485. We then replaced the prism with a reflection grating and after evaluating the spectra of a known bulb, namely Helium, we used our results to determine the elements in 3 unknown bulbs. We determined the bulbs to be comprised of Oxygen, Neon and Mercury. In the final experiment, we produced a set of transmission curves resulting from applying various filters to a continuum light source. These curves are shown in the “Calibrating Colour Filters” section.

Astrophysics Laboratory - Computing - 2012 (Year 4)

These experiments were a set of independent experiments, performing common astronomical tasks. The first experiment was to find the absolute magnitude of a standard star using CCD photometry. We used this result to analyse the magnitudes of a cluster of galaxies. We used a plot of colour against magnitude to determine which galaxies belonged to the cluster, and which galaxies are just unrelated foreground galaxies. From this plot, we found there was a relationship between the colour and magnitude, known as the red sequence. This was found to be (𝑣 − 𝑖) = −0.0941𝑚𝑖 + 3.7883. The second experiment was to compute the redshift of a quasar. This was done by analysing a known spectrum to wavelength calibrate the spectrum from the quasar. We then compared the spectra to a set of known values to determine the shift in wavelength of the observed lines compared to what they should be. From this, we computed to the redshift to be 𝑧 = 0.3806(2). Our final experiment was to use astrometry to compute the orbital radius of an asteroid from a photographic plate of the sky. Using some assumptions, we determined this value to be 𝑎 = 2.18(15)𝐴𝑈.

The Physics of High Momentum Impacts Into The Earth - 2011 (Year 3)

On 8th of November, 2011, an asteroid – 2005 YU55 - will pass within the orbital range of the Moon (1). At around 400 metres across, this asteroid would cause substantial damage if it were to impact into the Earth and could create a crater up to 5km in diameter (2). Thankfully, its trajectory is well determined, and it is more than likely to pass without issue. However, the physics of a collision of such a body, or bolide, is of great interest. How can we tell how a bolide will behave during decent through the atmosphere, and ultimately its impact into the surface? While the exact, numerical solutions to the outcomes of massive impacts are very complex and require a detailed knowledge of the impactor and specific area of impact(3), a paper by J. Gratton and C. Perazzo (4), shows the use of estimates and assumptions, to build a good working model of an impact of a considerably sized bolide. This allows for decent projections to be made, by knowing only very basic characteristics of the bolide – which can be easily determined from observations.