DISCnet Students Profiles
Aswin P Vijayan - 2017 Entry
University of Sussex
Simulations at the epoch of reionisation
I did my bachelors at the National Institute of Technology, Calicut (NITC), India in Engineering Physics which focuses more on applied physics like semiconductor technologies, thin films, nanotechnology. I then did a Masters at the Universteit Leiden, The Netherlands in Astronomy and Cosmology, where I became interested in structure formation in the early Universe, which I am currently engaged with for my PhD. I use large datasets from simulations, trying to correlate various properties of galaxies to determine if they are physically motivated. I hope that simulations will be able to predict some observational properties of galaxies and not usually the other way around. For this I frequently make use of python modules like numpy, pandas, h5py, scipy and matplotlib for plotting. And I believe the data analysis
skills that are to be used here are transferable to industrial applications if at certain point I wish to move outside of academia. This is also one of the main reasons for applying for a DISCnet CDT, since here you get a chance to test out the skills that you have been using for pure science outside of it.
What is your research?
Reionisation is the last phase transition in the Universe, where it underwent a transition from a neutral to an ionised state. This was caused by the formation of early galaxies,believed to host Population III stars, which hopefully would be detected by the upcoming JWST observation runs. Now the properties of these galaxies define the subsequent population of galaxies formed in the Universe, thus a proper study of this phase is important. In order to understand the physics that goes on at these scales and interpret observational data, the group that I am part of at the University of Sussex, hope to utilise both cosmological simulations as well as Semi-Analytical models (SAMs, which are much faster to run) of galaxy formation to study this epoch. First we plan to tackle the properties of dust at high redshift using SAMs and determine if a self-consistent dust model should be implemented in cosmological simulations or is it effective enough to implement one in post processing. We also plan to make use of some EAGLE (Evolution and Assembly of GaLaxies and their Environments) spin off projects to do zoom-in simulations of certain select density regions.
Metal surface density of a tidally interacting galaxy (Mstar ~ 10^(10)Msol) at z = 4.72 from one of the cluster EAGLE zoom in runs. Created using pynbody.
What have you done in the first 6 months?
I have been working on the latest version of the L-Galaxies SAMs, with an already implemented dust model. The model produces more amount of dust seen at the present epoch, and I am analysing the cause of that as well as trying to obtain an empirical relation between the amount of dust and metals in galaxies. I have also run zoom in simulations at high redshifts of the galaxy clusters which were selected as part of the Cluster-EAGLE (C-EAGLE/Hydrangea project). We hope to derive some meaningful results of the high redshift Universe from this.