The Galaxy group at Stockholm Observatory focuses on the physics of spiral galaxies including the Milky Way, especially the structure and dynamics of barred systems, nuclear activity including the Galactic Centre, and dark matter. Detailed studies are performed using the ESO telescopes, NOT and HST in the optical and infrared, and the VLA, AT and SEST in the radio regime.
The local burst of star formation in our Galaxy, giving rise to the phenomenon called Gould's Belt, is studied by means of observations by the Hipparcos satellite. Using recently published data, analyses of the kinematics of the Gould Belt stars are being made in terms of two models. (i) An inclined rotating selfgravitating and expanding system. (ii) A stellar density wave. From the observational data the parameters entering these two models are derived.
The Galactic Nucleus, at a distance of about 8 kpc and hidden behind 30
magnitudes of visual extinction by cool interstellar dust along the line of
sight, cannot be studied at visible, ultraviolet or soft X-ray wavelengths.
The radio and millimeter wave region research at Stockholm Observatory
concentrates on the distribution and kinematics of Galactic Centre
molecular cloud structures and their physical and chemical properties, as
well as their interactions with the radio continuum components, from the
inner parsec out to about a hundred parsecs from the Galactic Nucleus. In
August, the group had another observing session on SEST during which the
mapping of the immediate environment of Sgr A in the 
C
O
line was completed. The recalibration and map production of the four 18-cm
OH line observations, made with the VLA, were also completed.
Another project is aimed at mapping the molecular gas in the barred, grand-design, face-on, spiral galaxy M83 with the SEST. This galaxy is relatively nearby (3.7 Mpc), which makes it possible to do a detailed study of the kinematics of the gas, and correlate the distribution of the molecular gas with other tracers of stellar activity.
A major study of the effects of metallicity and far-ultraviolet radiation on the physical/chemical properties of the molecular gas in the Magellanic Clouds were completed this year. Among the results should be mentioned the abundance deficits, relative to the Galaxy, of all molecules by, on the average, a factor of ten in the LMC, and an additional factor of five in the SMC.