Dr Natasha Maddox

Biography

I completed my undergraduate MSci degree in physics at the University of Victoria, and my PhD in astronomy at the University of Cambridge. The topic of my PhD thesis was near-infrared selection of luminous quasars, where I created a photometric redshift code to efficiently select quasar candidates for spectroscopic follow-up.

I have held research positions in Germany, the Netherlands, and South Africa. Through this experience, I have developed extensive international collaborations, and have worked on topics ranging from fast radio bursts to high redshift quasars, using data from nearly every wavelength.

Research interests

My research now primarily focuses on multi-wavelength observations of galaxies, with particular focus on adding data at radio wavelengths. By adding information about the neutral hydrogen to the census of galaxy components, we have a better understanding of the past and the future of galaxies. I am a member of several MeerKAT Large Survey Programmes, I co-chair the HI working group of the MeerKAT Large Programme MIGHTEE, and I am an active member of the HI and Cosmology SKA Science Working Groups. Working with MeerKAT helps us prepare for the Square Kilometre Array Observatory, which begins operations in the coming years.

Next generation radio astronomy

We use radio telescopes to investigate the formation and evolution of galaxies, giving us a view into processes not visible at other wavelengths. We are observing both the neutral hydrogen, as the raw material for star formation, and the radio continuum emission from star formation and active galactic nuclei, using state of the art radio interferometers, including the South African telescope MeerKAT, and in the future, the Square Kilometre Array.

The most abundant element in the Universe, hydrogen is the raw material from which stars form. Neutral hydrogen only emits at radio wavelengths, so the only way to observe this fundamental material in emission is with radio telescopes. The emission from hydrogen is very weak, much fainter than the optical emission from stars, so large radio telescopes are needed to detect the signal. Observing the hydrogen reservoirs of galaxies not only tells us about their past star formation history, but also their future star formation potential. It is also very sensitive to disturbances, so gives clues about a galaxy's surroundings, and interactions with other galaxies.

The global astronomy community is collaborating on building the next large radio telescope interferometer, called the Square Kilometre Array Observatory (SKAO). With one telescope located across southern Africa, and another in Western Australia, these facilities represent the next generation of radio telescopes, enabling observations and discoveries not possible with existing instruments. The operational headquarters are located in Jodrell Bank, near Manchester, so the UK is a core partner in the SKAO project. By using existing telescopes for our research, such as MeerKAT, we will build expertise in advance of the start of SKAO operations in the coming decade, and be ready for the science the SKAO will enable.

Current researchers and PhD students

Former researchers and PhD students at Bristol

• Dr Hattie Stewart (PhD, 2019 - 2024. Now a postdoc in Dr Wakeford's group and moving on to Oxford University as a Schmidt AI fellow)