It's not rocket science…

(but it's close)

I am an astrophysicist interested in galaxies (and the rest of the Universe). My work is mainly numerical/theoretical (as opposed to observational/experimental). That is, I develop computer programs that simulate the physics of the Universe, and use these programs to interpret and predict real observations.

I'm particularly interested in the early Universe, how galaxies formed, and which physical properties governed the galaxies at that time. Why? Because galaxies are the magnificent and beautiful building blocks of our Universe. Understanding these guys helps us understand the cosmos around us and our place in it.

Specifically, I use hydro-dynamically simulated model galaxies, conducting radiative transfer of their emitted light out through the interstellar and intergalactic medium in order to calculate how they would actually look if observed from Earth.

In essence, by comparing real and synthetic observations, we can learn about the physics of the real ones, e.g. their masses, star formation, gas kinematics, temperatures, dust contents, etc. More generally, I would like to contribute to expanding our horizon, in one way or another.

Peter Laursen

Postdoctoral fellow at the Institute of Theoretical Astrophysics, University of Oslo.

Affiliated with the Cosmic Dawn Center, University of Copenhagen.


A carousel of my most recent activities.

Astronomical observations

Pretty images I took while observing in Chile, La Palma, and other places.

Selected Publications

As described in the research section, most of my work has been devoted to Lyman α radiative transfer in galaxies and the intergalactic medium.

See full list of publications

Intergalactic transmission and its impact on the Lyα line

  • Assessing how the circum- and intergalactic gas affects the Lyα spectral line.
  • Awarded Sweden's most cited astrophysical paper 2011.
  • Laursen et al. 2011, ApJ, 728, 52

    On the (non-)enhancement of the Lyα equivalent width by a multiphase interstellar medium

  • A systematic study of whether or not a clumpy interstellar medium can boost the Lyα-to-continuum ratio significantly, as has been previously assumed.
  • It can't.
  • Laursen et al. 2013, ApJ, 766, 124

    Chasing Lyman α-emitting galaxies at z = 8.8

  • Predictions of the expected detectability and physical properties of the most distant galaxies.
  • Analytical evaluation of the amount of cooling radiation from forming galaxies.
  • A mathematical tool for adding numbers with asymmetrical uncertainties.
  • Laursen et al. 2019, arXiv:1806.07392

    For non-astronomers (also for astronomers really)

    • Are you a non-astronomer and want to read a bit about astronomy? See my encyclopedia for non-astronomers.
    • Or do you have a question about astrophysics? Ask it at my Q&A column.
    • Maybe you're coder and just want to hack away? Check out the codes I've published on my GitHub repository.
    • So you are an astronomer or some other sort of researcher, and don't want to make the same stupid mistakes as I did? Have a look in my notes on everything from galaxies, to extinction laws, to Python cheat sheets, to LaTeX tips, and what not.
    • Not interested in astronomy at all? No offense taken — why not just sit back then and listen to my band Ampel.
    • No way! You like both music and astronomy? Will you marry me? While you think about it, listen to my astrosong playlist (or check out my other Spotify playlists).
    • Ha ha listen so when I said "Will you marry me?" I was only kidding because I'm married to this hot mama.
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    A galaxy

    A simulated galaxy, maybe, but a galaxy nontheless.