Astro Research Showcase

Dr George Dransfield

• On the hunt for warm giant planets
  The field of exoplanets recently hit a new milestone: discovery of the 6000th exoplanet. But despite this huge (and growing) sample size, detection of new planets still has a crucial role to play in our field. In this talk I will describe my current discovery projects, where I target temperate gas giants orbiting hosts of different spectral flavours.

Dr Sara Maleubre Molinero

• The impact of galaxy bias on cross-correlation tomography
  We present a tomographic reconstruction method that uses cross-correlations between galaxies and other large scale structure tracers to recover the cosmic mean of key physical quantities, such as halo bias–weighted electron pressure and star-formation density. Using the FLAMINGO simulations, we demonstrate that these measurements can be made robustly and interpreted within the halo model, independent of the clustering properties of the galaxy sample.

Niamh O'Sullivan

• Tackling Supergranulation in Earth-Twin Surveys using the HARPS-N Solar Data
  In recent years supergranulation has emerged as one of the biggest challenges for the detection of Earth-twins in radial velocity (RV) planet searches. Supergranulation introduces RV variations on timescales of 1-2 days with amplitudes of 0.5-1 m/s, considerably larger than the expected 10 cm/s signal from Earth-like planets. I will present new work focused on mitigating the impact of supergranulation using Gaussian Processes in the time domain. I will apply this new method to HARPS-N solar data sets, and show how this method has led to the discovery of a ‘supergranulation cycle’, in phase with the activity cycle of the Sun. I will also discuss observational strategies that can be employed to characterise supergranulation in other stars, a critical step in the search for Earth-twins.