Hi, i'm Peter.



My name is Peter Boorman, and I'm a postdoc in the NuSTAR group at Caltech in Pasadena, California.

I have a broad range of research interests that mainly revolve around the process of accretion onto compact objects. I dedicate a lot of my time to the growth of supermassive black holes billions of times more massive than our Sun. These black holes reside at the centres of every large galaxy, and I want to know how they grew to the extreme masses we see today.


Key science questions

See the projects below for more information about how I'm trying to solve these questions.

  • How many supermassive black holes are actively accreting at different cosmic epochs?
  • Are supermassive black holes scaled-up versions of smaller black holes?
  • Do supermassive black holes grow by eating material from other galaxies, or themselves?
  • How similar are the environments close to accreting supermassive black holes?

My research

Obscured accretion & NuLANDS

Most mass is accreted onto supermassive black holes behind thick veils of obscuring matter, making it difficult to construct a census of supermassive black hole activity. The NuSTAR Local AGN NH Distribution Survey (NuLANDS) is dedicated to finding out how many galaxies in our local cosmic neighbourhood host actively accreting supermassive black holes, on average. Click here to see a poster all about NuLANDS that I presented at the 2021 EAS meeting.

Black hole spins

Astrophysical black holes are described by two main parameters, mass and spin. Though many black hole masses have been estimated in a variety of different ways, comparatively fewer black hole spins have been measured to date. We are investigating ways with current and future instrumentation to construct a census of supermassive black hole spin.

X-raying Green Peas

Green Pea galaxies are compact starburst dwarf galaxies, analogous to the earliest galaxies that reionised the Universe. The light detected from Green Pea galaxies was thought to be powered by star formation, yet X-ray detectors have found some to be "over-luminous" in X-rays to what is expected from purely star formation. What could be powering such extreme X-ray emission in these sources?

AGN accretion states

Stellar mass accreting black holes are known to go through cyclic outbursts described by changes in luminosity and spectral hardness, aka accretion states. We are investigating whether or not supermassive black holes exhibit similar accretion states, and what analogies can be made with accreting stellar mass black holes.


Peter Boorman

Research Interests: Obscured accretion of supermassive black holes, Monte Carlo radiative transfer modelling, Big data analysis and machine learning methods


PhD in astrophysics

2015 - 2019

Department of Physics & Astronomy, University of Southampton, Southampton, UK

Thesis title: The Obscured Accretion and Growth of Supermassive Black Holes
Awarded the Springer Thesis prize - link here.

Integrated Masters in Physics

2011 - 2015

Department of Physics & Astronomy, University of Southampton, Southampton, UK

Dissertation title: Gravitons in Geneva
Finished top of the year with first class honours - link here.

Professional Experience

Postdoctoral researcher

2022 - present

California Institute of Technology, Pasadena, US

    Working on obscured AGN, AGN selection techniques & accretion states. Using X-ray spectroscopy, optical spectroscopy and multiwavelength photometry.

Postdoctoral researcher

2019 - 2022

Astronomical Institute of the Czech Academy of Sciences, Praha, Czechia

    Working on obscured AGN, AGN selection techniques & accretion states. Using X-ray spectroscopy, optical spectroscopy and multiwavelength photometry.

MoleGazer data analyst


University of Southampton, Southampton, UK

    Funded from STFC Impact Acceleration Accounts to analyse the temporal evolution of naevi into melanoma in medical images using astronomical photometric techniques and machine learning algorithms. Click here to learn more.



A (continually-updated) compilation of plots from my research — .

Springer Thesis award

My PhD thesis (entitled The Accretion and Obscured Growth of Supermassive Black Holes) was awarded a Springer Thesis prize. See more info here.

Introductory X-ray textbook published

Our textbook; Tutorial Guide to X-ray and Gamma-ray Astronomy, is now published and available from Springer at the link above.

Publish & Flourish: Lindau Sciathon 2020 article submitted

In 48 hours, our international team created a series of recommendations to nourish a mutually respectful publishing process with researchers in the Lindau Sciathon.


Using artifical intelligence with astrophysical transient detection techniques, MoleGazer aims to track the evolution of moles and aid the early diagnosis of melanoma. Click the link to find out more!

NASA press release

We used NASA's NuSTAR telescope to study a nearby heavily obscured accreting supermassive black hole (Boorman et al., 2016; ApJ-833-245). See more from: NASA, the Guardian, the Independent, University of Southampton.





Peter Boorman