a selection of projects I’ve worked on

Finding new open clusters with Gaia

Open clusters are key structures in the Milky Way, typically formed of tens to hundreds of stars. Their constituent stars formed at the same time and from the same material, making them into useful objects to study. I’m using cluster-detection algorithms and statistics to probe Gaia’s data of the Milky Way for new open clusters.

Galaxy redshifts with machine learning

Ever-larger photometric galaxy catalogues require sophisticated techniques to derive redshifts efficiently and robustly. In my Master’s project, I used a mixture density network (a type of neural network) to derive accurate redshifts for galaxies in the CANDELS GOODS-South field. I showed that machine learning could be viable for galaxy redshift determination, although more training data would be necessary to improve the results of the method.

De-reddening Cepheid variables with Gaia

Cepheid variable stars are the bottom rung on the cosmic distance ladder. Accurately measuring their characteristics is essential to derive robust cosmological parameters, but this is greatly complicated by stellar extinction. I used Gaia parallaxes and a Bayesian inference framework in Python to independently and precisely derive Leavitt law (period-luminosity relation) parameters, along with extinctions to each individual star.