Are you interested in our research topics and would consider an independent fellowship in our group? We are very happy to support suitable candidates for Marie Sklodowska-Curie Fellowships , Newton Fellowships or other independent fellowship schemes. Please get in touch via email to discuss options.
The Extragalactic Dusty Astrophysics group offer opportunities to get involved into our research in the course of a PhD project. Projects may focus on observational and/or theoretical aspects of active galactic nuclei or cosmology. Please check out the Astrogroup's Postgraduate opportunities website. This will include the group's projects as well as other projects by staff members of the astrogroup. Example project offered this year:
Snap-chatting with the universe
Astronomy is undergoing a revolution. New surveys are regularly scanning the sky and create movies rather than static images of the sky. This allows us to capture how stars explode or how black holes accrete mass over time with for large samples of objects.
In Southampton, we are leading VEILS and VOILETTE, infrared and optical time-domain surveys with goals that range from discovering and characterising distant supernovae to mapping the variations in the growth process of supermassive black holes in the centre of galaxies. These variations will be used to reveal the physics at play that lead to the most energetic radiation output in the universe. In addition, we can measure time lags between variations in the optical and infrared and constrain the equation-of-state of the elusive dark energy that fills about 70% of the universe.
As a student on this project, you will take a leading role in the VOILETTE survey. You will be working on the discovery of new transient objects and the identification, classification, and interpretation of variable supermassive black holes. This will involve a large range of skills from data reduction of a large stream of data, machine learning techniques to identify variable sources, to developing physical models to interpret the data. You will be part of an international team with partners across Europe, the Americas, and Asia.
More information on VEILS can be found here.
Zooming into the hearts of active galactic nuclei
How do black holes grow and how do they influence their host galaxies in the process? All big galaxies in the universe host a supermassive black hole with millions to billions of solar masses in their centre. We know now that these black holes are fed by accretion of mass from their surrounding and that the growth is tightly connected to the evolution of the host galaxy. However, the exact mechanisms are not fully understood, in part because the mass accretion takes place on very small spatial scales. The resolution power to see these processes is equivalent to resolving the distance to the nearest stars of our sun in galaxies tens of millions of light years away. Since few years, this resolution power is available in the infrared (IR) by making use of the Very Large Telescope Interferometer (VLTI) at Paranal in Chile, where up to four 8m-class telescopes are combined to provide the resolution power of a 130m telescope. Such observations revealed how dusty gas is distributed around the black hole and led to the discovery of a new dusty wind structure that is responsible for the bulk of the IR emission.
A new instrument, MATISSE, is currently being commissioned at the VLTI, which will enable us to reconstruct first real images of the accreting dust and gas. With this instrument, we will get a first panchromatic view of the accretion and outflow of hot and cold gas. In the course of the PhD project, you will be amongst the first to use this instrument for scientific exploitation. You will be trained on interferometry data reduction and modelling, including further development on radiative transfer models.
Dust storms from supermassive black holes
Actively growing supermassive black holes are the most energetic objects in the universe. It has recently become clear that our standard picture of this growth process is incomplete: While it was considered that the bulk of the dusty gas around the supermassive black hole is distributed in a disk-like configuration, observations at the highest angular resolution in the infrared showed that significant mass is associated with a dusty wind streaming away from the black hole environment. This adds to the known outflows of highly ionised gas that are a common feature in these active galactic nuclei. However, dust is associated with high densities, meaning that these dusty winds may well carry the bulk of the mass in these outflows, providing a long-sought link between black hole growth and powerful feedback into the galaxy.
No current physical model is able to explain the dusty wind features. A favoured mechanism for launching such a wind is optical and ultraviolet radiation pressure from the accretion disk onto the dusty gas, as well as infrared radiation pressure from the dusty gas itself. These processes are not considered in models yet in a self-consistent way since they connect global with local emitting processes, which is very computationally expensive and needs advanced simulation techniques. In the course of the proposed PhD project, you will contribute to a large, ERC-funded effort with the goal of developing a new model for 3-dimensional radiative hydrodynamical simulations of dust and gas around actively growing supermassive black holes. The project will train you in high-performance computing, radiative transfer, hydrodynamics, and statistical interpretation.
We also support PhD projects in collaboration with ESO, Europe's flagship optical observatory. These studentship will allow spending time in both Southampton and one of ESO's locations in either Germany or Chile. Application deadlines via the ESO recruitment portal are on 15 May and 15 November of each year. If you are interested in this opportunity, please contact Dr Sebastian Hoenig via email at least one month ahead of the respective deadline. Note that you will have to apply to both the University of Southampton and ESO in this case, and support from the university will be a prerequisite for a succesful application to ESO.