Research

Centaurus A, my favourite galaxy ❤️ (Credit: ESO)

Do Black Holes Kill Galaxies?

We think that all massive galaxies have supermassive black holes in their centres. Most of the time, they don't have much effect on the wider galaxy, but in around 10% of cases, the black hole is able to suck gas into an 'accretion disc' which generates a huge amount of energy. This energy can be released back into the galaxy through huge outflows, like the two jets seen in Centaurus A (left). My research is on how these outflows interact with the galaxy and whether they can shut down star formation, killing the galaxy.

Cosmological Simulations

Cosmological simulations (such as IllustrisTNG, EAGLE and SIMBA) require feedback from black holes in order to reproduce many observed quantities, such as galaxy stellar mass functions. However, on a population-scale, observations seem to find that AGN live in gas-rich and star-forming galaxies. This has led some observers to question whether AGN is effective. In this study, we analysed these cosmological simulations using the same techniques observers use, and found that the simulations also predicted AGN to live in gas-rich and star-forming galaxies (see Figure). This is despite them employing effective feedback models. This shows that the lack of population-level evidence for feedback cannot be used to disprove the effect of AGN on galaxy quenching. For more details, you can check out the paper here: (Ward+22).

AGN in Clumpy DisCs (ACDC)

My current project is building my own idealised galaxy simulations to understand how AGN winds interact with the substructure of the interstellar medium (ISM) to launch large, multi-phase outflows. I use the AREPO hydrodynamic code combined with the BOLA wind model (Costa+20). We are finding very interesting results regarding how the outflow interacts with the clumpy structure of the ISM, creating small fragments of cold gas that then get entrained in the outflow. We're planning on publishing our first paper on these simulations soon, so stay tuned!

Observational Collaborations

Throughout my computational research, I've tried to stay in close collaboration with observational groups to improve our mutual understanding of the science we're studying. I'm a member of several international collaborations and am co-author and co-PI on several exciting papers and accepted observing proposals:

The Quasar Feedback Survey (QFeedS) is a multi-wavelength survey of nearby quasars, with a wealth of optical IFS, radio and X-ray data on their targets.
SUPER is a survey of quasars at a redshift of z~2. I'm co-I on two accepted JWST proposals, looking at H2 roto-vibrational lines and PAH emission.
LUDO is a proposed LOFAR2.0 large survey looking to survey the Euclid Deep Field North at an angular resolution of 0.3 arcsec at very low frequencies (150 MHz).

Simulated Radio Emission

During my masters at Durham University, I worked with Dr Leah Morabito and Prof Dave Alexander to simulate a population of radio galaxies and make mock LOFAR images of them. This was to test the limits of a technique using a combination of the 5 arcsec and 0.3 arcsec beam sizes of LOFAR to separate AGN emission from star formation (Morabito+22).