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?
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.
Bayesian X-ray Analysis tutorial
Bayesian X-ray Analysis (BXA) is a package to robustly estimate parameter uncertainties, perform Bayesian model selection and so much more. Follow the link for a tutorial on how to use many different aspects of BXA, and click here for the accompanying video tutorials.
Prague AGN seminar series (October — December 2021)
Click here to see the details for the autumn 2021 Prague AGN seminar series, including links to recordings where available.
X-ray Spectral Fitting 2022
The XSF22 winter school was dedicated to learning how to use the Bayesian X-ray Analysis software platform. Click the link for more information or for access to the school materials.
For a full CV, please get in touch with me directly.
Summary
Peter Boorman
Research Interests: Obscured accretion of supermassive black holes, Monte Carlo radiative transfer modelling, Big data analysis and machine learning methods
- 1216 E. California Blvd., Pasadena, CA 91107
- boorman[at]caltech[dot]edu
Education
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
2019
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.
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.
MoleGazer
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.