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Welcome to the Northernmost astrophysics group in the
world.
We are at the 65th parallel.
The astrophysics group studies
accretion-powered high energy sources such as neutron stars and black
holes as well as gamma-ray bursts. Our strength is the combination of
observational and theoretical
research. We are actively involved in the analysis of the data on
accreting black holes,
ultraluminous X-ray sources and accreting millisecond pulsars obtained
with the X-ray and gamma-ray
observatories RXTE, XMM-Newton, INTEGRAL and Fermi. We also develop
theoretical models for boundary layers
around neutron stars and super-Eddington accretion disks around black
holes. We have pioneered
theoretical modelling of the light curves from rapidly rotating neutron
stars and have developed
state-of-the-art computer code for modelling the radiative processes in
relativistic plasmas.
We work on the analysis of the Fermi/LAT data from blazars, which
are supermassive blackholes with relativistic jets pointing towards us and emitting most of the energy in the GeV range. We have found that
their spectra have significant breaks in the GeV range that are well
described by the absorption of the gamma-rays due to the
photon-photon pair production on He II Lyman recombination continuum and
lines. This has resolved a long-standing question of gamma-ray production
and proved that gamma-rays are produced within the broad-band
line region.
We have also proposed a novel
particle acceleration
mechanism--"photon breeding"-- that operates in relativistic jets emanating
from active galactic nuclei.
Here you can find an introduction to the
high energy astrophysics in
English and in Finnish.
Finnish Graduate
School in
Astronomy and Space Physics
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[Faculty
of Sciences] > [Dept.
of Physical Sciences] > [Astronomy] > [Astrophysics]
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