About the project
Quasars are among the brightest lights in our Universe and powered by accretion onto supermassive black holes. With the advent of very large, highly multiplexed wide-field spectroscopic surveys, we are entering a golden age for studies of quasar demographics where the rest-frame ultraviolet and optical spectra can be used to characterise the accretion and outflow properties in large statistical samples extending out to the highest redshifts when the first galaxies were forming.
The largest sample of spectroscopically confirmed quasars to date comes from the Sloan Digital Sky Survey (SDSS), which has provided us almost a million quasar spectra out to redshifts of 6. On account of the bright flux limit and optical wavelength coverage of SDSS however, it is not sensitive to both more distant and obscured quasars. In the former case the optical light is attenuated by dust around the quasar or in the quasar host galaxy while in the latter case it is redshifted into the infrared region of the electromagnetic spectrum.
As part of this PhD project the student will have proprietary access to two new, state-of-the-art spectroscopic survey datasets from the 4MOST spectrograph on the ESO VISTA telescope and the MOONS spectrograph on the Very Large Telescope, which are due to begin observations in 2024-2025. Our team in Southampton is leading observations of high-redshift and dusty, red quasars with these new facilities, which will open new parameter space for quasar discovery and characterisation. 4MOST can probe an order of magnitude deeper than SDSS and MOONS extends into the near infra-red wavelengths where the effects of dust attenuation are much less marked. As a result, they offer an unprecedented opportunity to extend the census of known quasars into the distant and obscured Universe. How many such quasars are out there? Are their properties such as black hole mass, strength of outflows, host galaxy characteristics - similar to, or different from the well-established optically selected population from SDSS? The PhD will be observationally driven and motivated by the new findings with the 4MOST and MOONS proprietary data to which you will have access.
You will be part of a vibrant and growing research team at Southampton including PhD students and postdoctoral researchers exploiting the latest multi-wavelength surveys and datasets to understand the high-redshift Universe. The project will give you an opportunity to join the 4MOST and/or VLT-MOONS Guaranteed Time Observation consortia and to work with scientists in the UK, Europe, USA and Chile.
