OnsalaSpace Observatory, the Swedish National Facility for Radio Astronomy, provides scientists with equipment to study the Earth and the rest of the Universe. The observatory operates two radio telescopes in Onsala, 45 km south of Gothenburg, and takes part in several international projects. Examples of activities:
The 20 and 25 m telescopes in Onsala: Studies of the birth and death of stars, and of molecules in the Milky Way and other galaxies.
LOFAR station: The Swedish station in the international radio telescope LOFAR is located at the observatory.
VLBI: Telescopes in different countries are linked together for better resolution.
The 25.6 m diameter, polar mount decimeter-wave telescope in Onsala is equipped with receivers for frequencies up to 7 GHz. It is used for astronomical VLBI observations. It is also operated as a single dish for studies of molecular clouds in the Galaxy. The telescope was built in 1963.
20-metre telescope
The 20 m diameter millimetre wave telescope in Onsala is equipped with receivers for frequencies up to 116 GHz. It is used for observations of millimetre wave emission from molecules in comets, circumstellar envelopes, and the interstellar medium in the Galaxy and in extragalactic objects. The telescope is enclosed in a radome of diameter 30 m. It is also used for astronomical VLBI observations of star forming regions, radio stars, and active galactic nuclei, and for geodetic VLBI observations to study e.g. crustal dynamics and polar motion. The telescope was built in 1975-76 and upgraded in 1992. It is also used, as part of the European and worldwide networks, for astronomical Very Long Baseline Interferometry observations of star forming regions, radio stars, and active galactic nuclei, and for geodetic VLBI observations to study e.g. crustal dynamics and polar motion.
Receivers
The telescope is equipped with the following receivers:
Frequency range
Receiver temperature
Receiver type
Polarization
2.2–2.4 GHz
60 K
HEMT amplifier
Single
8.2–8.4 GHz
80 K
HEMT amplifier
Dual
18.0–26.0 GHz
30 K
HEMT amplifier
Dual
26.0–36.0 GHz
50 K
HEMT amplifier
Single
36.0–49.8 GHz
50 K
HEMT amplifier
Dual
85–116 GHz
80–130 K
SIS mixer
Single
LOFAR station
The Swedish station in the international radio telescope LOFAR is located at Onsala Space Observatory. It was completed in 2011.
Nordic ALMA node
The Onsala Space Observatory currently hosts the Nordic ALMA node, which is part of the European ALMA regional centre. The Nordic ALMA node provides face-to-face support for any astronomer that wants to use the ALMA telescope and primarily supports the Nordic scientific community.
