About me


I am a computational astrophysicist studying high-energy astrophysical phenomena around neutron stars and black holes. For my research, I use both theoretical “pen-and-paper work” and large-scale supercomputer simulations.

I am also the Principal Investigator of the European Research Council (ERC) funded research project ILLUMINATOR. The project aims to unravel how neutron stars generate their observed electromagnetic radiation.

I am an Associate Professor of Astrophysics at University of Helsinki and Associate Research Scientist at Columbia Astrophysics Laboratory. Previously, I was a joint Flatiron Research Fellow in Center for Computational Astrophysics, Flatiron Institute and a Postdoctoral Researcher in Columbia University (2020-2023; New York, USA). Before coming to New York, I was a Nordita Fellow in Nordic Institute for Theoretical Physics (2018-2020; Stockholm, Sweden).

You can read more about my research here and on our group page.

In Finnish/Suomeksi:

Olen suomalainen astrofysiikan apulaisprofessori Helsingin yliopistossa. Tutkin pääasiassa suurenergia-astrofysiikan ääri-ilmiöitä, kuten neutronitähtien purkauksia, pulsarien säteilyä, mustien aukkojen kertymäkiekkoja, sekä kosmisia radiopurskeita.


Recent posts

CGS units

List of CGS units and constants used in especially in astrophysics

Alfven Wave Turbulence

PRL on how Alfven-wave turbulence can heat astrophysical plasmas around black holes and neutron stars.

Radiative turbulent flares

We performed new radiative kinetic simulations of reconnection-mediated turbulent flares - these flares are a new way to energize plasmas around neutron star...

Spreading layers around neutron stars

When an accretion disk around a neutron star touches the star, it can form a so-called spreading layer. In a work led by P. Abolmasov, we designed a new 2D s...

Quark-matter cores in neutron stars

Our new EOS analysis published in Nature Physics indicates that neutrons stars actually have two distinct phases of matter inside: normal hadronic and a siza...

Introduction to Julia

My teaching material for an introductory course on the new high-level, high-performance programming language called Julia is freely available here.

Arcmancer: general purpose ray tracer

In the project led by Pauli Pihajoki, we took ray tracing and numerical differential geometry to the next level. Images of black holes, disks, neutron stars?...

Helium composition in 4U 1820-303

In the work led by Valery Suleimanov, we applied the direct cooling tail method to constrain the atmosphere composition of a neutron star in 1820. Our result...

Direct cooling tail method

Here we derived some corrections to our existing cooling tail method. This new method is then applied to a previously measured neutron star, identifying abou...

Heavy metal neutron star atmospheres

What happens to the observed spectrum of neutrons stars when the atmosphere is full of heavy metals from the nuclear burning? On this article, published in A...