CEA News, March 2021
CEA PhD student awarded STEM for Britain Medal
Vicky Fawcett, a PhD candidate at the Centre for Extragalactic Astronomy, has been awarded Silver at the STEM for Britain competition, receiving a medal and a £750 prize for her work showing that red quasars prefer small scale radio emission and are most likely red due to dust.
Spectrum of a blue quasar compared to a red quasar; the red spectrum is
consistent with dust reddening [5]. Inset shows the Oxygen lines for a single
red quasar; the broad green lines indicate the presence of winds.
STEM for BRITAIN is an annual poster competition, usually held in the House of Commons, that aims to help politicians understand more about the strong engineering and scientific research undertaken in the UK. There are categories for Physics, Chemistry, Biology, Engineering and Mathematics, each of which had 10 finalists and 3 winners from a pool of approximately 200 researchers across the UK. Each finalist presented their poster to a judging panel on Thursday, March 4th, and the winners were announced on Monday, March 8th.
Vicky presented her research into quasar physics and how they may link in galaxy evolution. She showed that while most quasars appear very blue, there are some that show much redder colours. These “red quasars” could be an important link in galaxy evolution and so understanding their properties is very important. A group at Durham have found fundamental differences in the radio properties of red quasars that support this scenario. In Fawcett et al. 2020, high resolution radio data was used to further explore these differences; finding that red quasars show an enhancement in compact radio emission and are not driven by star-formation. In her latest work she uses ultraviolet-to-near-infrared quasar spectra to find that the red colours are caused by dust and there are no significant differences in the black hole properties of red quasars, indicating the differences they find in the radio properties may be driven by outflows; an important component of galaxy formation. These results add weight to the emerging picture of red quasars being fundamentally different objects to blue quasars, and potentially represent an important phase in galaxy evolution.