Mark Pearce

Brief bio

(More details in my curriculum vitae and publications list)

As professor of physics with specialisation in astroparticle physics, I develop instrumentation and methods which enable the study of the cosmic radiation from space platforms. My current research interest is X-ray polarimetry - a new observation method allowing celestial sources to be studied in a systematically different way to contemporary approaches based on imaging, timing and spectroscopy.

From September 2025, I am Head of the Particle Physics, Astrophysics, and Medical Imaging Division at the KTH Physics Department.

Between January 2020 - July 2024, I was Deputy Dean of the School of Engineering Sciences at KTH, and, 2012-2019, I was Head of the KTH Physics Department.

In 2020, I was elected to the Royal Swedish Academy of Sciences.

From 2026, I am Director of the KTH Space Centre.

Current research

Since ~2004, I have been leading the development of novel instrumentation at KTH to study the emission of linearly polarised hard X-rays (~10-100 keV) from compact celestial sources, such as black holes, neutron stars and gamma-ray bursts. The first phase of the work was completed in 2016 with the development of a unique telescope for observations of the Crab - a pulsar and associated wind nebula in the constellation of Taurus, 6500 light years from Earth, and Cygnus X-1, a black hole binary system. Observations were conducted from a stabilised balloon-borne platform operated in the stratosphere. The mission, known as PoGO+, flew in summer 2016 from Esrange, as described in this film.

In order to achieve at least an order of magnitude improvement in signal-to-background ratio compared to PoGO+, we are now part of the XL-Calibur Collaboration. An X-ray mirror to focuses X-rays over 12 m onto a compact polarimeter, which is housed inside an anticoincidence system (designed and built at KTH). XL-Calibur was launched from the Esrange Space Centre in northern Sweden in summer 2022 and 2024, improving the precision of Crab and Cyg X-1 measurements. We are now preparing to conduct a flight from McMurdo base on Antarctica for the study of high-energy sources on the southern sky.

In 2024, I joined the COMCUBE-S Collaboration, which aims to establish a swarm of about 30 16U-CubeSats in low-earth equatorial orbit. Each satellite is equipped with an X-ray polarimeter and a X-/gamma-ray spectrometer (which is developed in my group). We are currently performing Phase A studies under the European Space Agency and hope to launch a two-satellite demonstration mission in a few years time.

Last but not least, I am exploring a new type pf refractive X-ray optics, with a much shorter focal length than is currently possible. The optics is manufactured using two-photon polymerisation. The concept is described here, and the manufacturing process is outlined here.

Previous research

Between 1999 and 2016, I worked on cosmic-ray physics (PAMELA mission) with a focus on using antiparticles as a probe of potential primary sources such as dark matter particle annihilations. In the distant past (1996-2001), I developed radiation tolerant opto-electronic read-out solutions for the ATLAS experiment at CERN. My Ph.D. Thesis (University of Birmingham, 1996) concerned studies of b-quark hadrons using data from the OPAL experiment at the CERN LEP accelerator.