You can always write me at 
if there's anything you want to know more about.
Most of my research is ultimately about finding out as much as possible about the Universe,
in particular about the galaxies, which are gigantic assemblages of billions of stars,
roughly the same amount of gas, a little dust, og then probably some unknown so-called dark matter.
Lyman α radiative transfer:
My main expertise and interest lies in the field of Lyman α radiative transfer (RT).
When galaxies form, they are expected to emit massive amounts of Lyα photons
which, if interpreted correctly, may reveal much about how the galaxies formed, and
which physical conditions governed them.
During my Ph.D. I developed a numerical code
("
MoCaLaTA")
that simulates the Lyα RT in the
interstellar medium, enabling us to predict and interpret various properties of the
appearance and the spectra — and hence of the nature — of young galaxies.
• Ph.D. research
• Lyα radiation
• Radiative transfer
Reionization of the Universe:
A different code, also developed during my Ph.D., calculates the RT in the intergalactic medium (IGM).
Besides revealing how the spectrum from Lyα emitting galaxies is altered by the surrounding IGM, we could also
use it to constrain the time at which the Universe was reionized by the hard UV radiation escaping
the first galaxies, the so-called
Epoch of Reionization.
• IGMtransfer (the code)
• Epoch of Reionization
Cosmic dust:
A very important ingredient in Lyα RT is dust. Since Lyα scatters millions of times
on neutral hydrogen before escaping a galaxy, its path length will be tremendously increased,
and thus even a tiny amount of dust mixed within the gas may be able to absorb a significant
fraction of the photons, and even reshape the spectrum. To this end I implemented a model of dust in
MoCaLaTA.
• Dust
Gamma-ray bursts:
Gamma-ray bursts (GRBs) are violent explosions marking the death of a massive star
(or two compact objects such as neutron stars or black holes). To learn about the nature
of the surrounding environments of such objects, I have modified
MoCaLaTA
to simulate the RT of X- and gamma-rays, enabling us to put constraints on the metallicity
of the gas in which GRBs are born.
• Gamma-ray burst
Lyα emission from damped Lyα absorbers:
Damped Lyα absorbers are huge clouds of neutral hydrogen, discovered
as broad absorption lines in quasar spectra (or other bright objects),
thought to be the progenitors of present-day's galaxies. If so, in principle they
should also be observable in
emission, in particular in Lyα emission,
due to star formation. However, this has been seen only a few times, so any new detection
is still interesting. Thus, we continuously carry out observations targeting metal-rich
DLAs from the SDSS, using the
X-shooter
at the
VLT, Chile..
• Damped Lyα absorbers