Welcome to Lars Frogner, PhD student at RoCS

"By the time I was in upper secondary school I knew exactly how I wanted to proceed in the following years"

Lars Frogner (left) and his astrophotography equipment set up in the backyard a moonlit evening (right). A DSLR camera is busy imaging a nebula though the telescope. Credits: Lars Frogner

Since his early teenage years Lars' interest in astronomy has kept growing. 

– I soon got myself a telescope and started taking pictures through it (something I still do regularly, by the way). 

After a short (summer) break from his graduation, Lars began his doctoral studies in August 2018.

I worked on a numerical model for the transport and deposition of energy via accelerated electrons associated with nanoflares. In my PhD, the electron transport code from my master’s will be developed further and I'll explore its results in more detail.

Magnetic reconnection: still a mystery

It has long been known that the outer layers of the solar atmosphere are very hot, and the possible sources of this heating and their relative importance are still debated. One important source of heat is the release of magnetic energy when separate magnetic loops are forced together. Among other things, this leads to the acceleration of charged particles to extremely high speeds.

The overall topic of my PhD is to better understand how these particles behave and how they influence the solar atmosphere.

Advanced computer simulations

Rate of heating of the plasma due to the electron beams in a simulation box, averaged over all depths. Credits: Lars Frogner

Bifrost, the 3D magnetohydrodynamic (MHD) code which researchers at RoCS use to simulate the solar atmosphere, does not include all the physics required to study these events in detail.

– What is your approach?

 I will work mainly with modelling, in particular with extending the Bifrost code to handle accelerated particles.

I will also look more into the modelling of other processes that are important for understanding accelerated particles, especially magnetic reconnection. Ultimately the aim is to compare the results with existing observations.

Living in Oslo, the "big city"

– As soon as I moved to Oslo I liked it right away. In addition, Oslo is just a 90 minute train ride away from my home city of Hamar, so the choice of studying at UiO was quite easy.

After over five years at the University of Oslo, Lars starts to feel like at home here. 

– What's your experience at ITA so far?

ITA is the best and the only place to study astronomy in Norway. After I began my PhD, I’ve gotten to know my colleagues here a lot better. This is made a lot easier by the open and relaxed community we have at the institute, which I very much appreciate.

– Your expectations?

– With ITA being known for producing high quality research, and in particular with RoCS being a Centre of Excellence, I do think we newcomers have some high standards to live up to. My expectation is that the centre and institute will continue to facilitate this by providing helpful guidance and good working conditions.


Published Jan. 9, 2019 11:39 AM - Last modified Jan. 9, 2019 11:39 AM