Artist’s impression of an Active Galactic Nucleus
Credit: ESA/NASA, the AVO project and Paolo Padovani
At the heart of pretty much every galaxy, including the Milky Way, there is a supermassive black hole (SMBH). Most of these SMBHs are inactive in the present-day Universe. However, in the past, they were active, meaning they were accreting huge quantities of matter. This process is thought to be critical in galaxy evolution, as it explains the co-evolution of galaxies and their central black holes, and provides a mechanism to quench star formation in galaxies.
Galaxies hosting such active black holes are called AGN — active galactic nuclei. They can be found in large surveys looking for the signatures of black hole accretion in the light we detect from the galaxies: X-ray emission from hot gas being accreted into the SMBH, mid-infrared emission from a dusty torus surrounding the accretion disk, and radio emission from jets coming out of the black hole.
In this project, the student will exploit the newly-released COSMOS2025 catalogue of galaxies, which includes Hubble, James Webb, and Spitzer space telescope data, to find distant AGN. By cross-matching with additional X-ray, infrared and radio catalogues, the student will characterize the multi-wavelength emission from these galaxies. The first goal is to obtain a sample of AGN identified through various means, and a control sample of non-AGN star-forming galaxies. The second goal is to model the spectral energy distributions of these galaxies using the MAGPHYS+AGN code to answer the following questions:
- What is the overlap between different AGN selection criteria?
- What can their spectral energy distributions tell us something about the dusty torus surrounding the black hole?
| Student attributes | |
| Academic background | Astronomy/Physics |
| Computing skills | Basic skills (e.g. python) beneficial |
| Training requirement | None |
| Project timeline | |
| Week 1 | Inductions and project introduction |
| Week 2 | Initial presentation |
| Week 3 | Download and manipulate the catalogue |
| Week 4 | Obtain AGN sample and control sample |
| Week 5 | Install and run MAGPHYS |
| Week 6 | Plot and analyse results |
| Week 7 | Discuss results |
| Week 8 | Prepare final presentation and report |
| Week 9 | Final presentation |
| Week 10 | Final report |