Stockholm Observatory has a research group specializing in observational
and theoretical high energy astrophysics with emphasis on radiation
processes in high energy plasmas and their applications when
interpreting broad band observations
of active galactic nuclei, X-ray binaries, pulsars, and 
-ray bursts.
Observations are both space-based (GRANAT, ASCA,
CGRO, XTE) and ground-based (NOT, ESO).
Archival data are also used. The observatory participates in the experimental
team for the Spectrum Röntgen-Gamma (SRG) satellite and is
Co-Investigator for the Joint European X-ray Monitor (JEM-X) on
INTEGRAL.
Unique modelling tools based on Compton scattering/radiation transfer
codes
in the X-rays have been developed and included in the XSPEC software
package. The tools are used to model X/ -spectra of AGN and
X-ray binaries.
For AM Her objects, the quasi-periodic oscillations are studied in order to
deduce the physical properties of the accretion column above the white dwarf.
For pulsars, the electron acceleration and the subsequent generation of
coherent radiation, as well as the geometry of the
emission cone(s) are studied. The average statistical properties of more
than 1000 -ray bursts are studied and simulated with a pulse avalanche
model in order to identify the underlying physical processes.