The quasar monitoring with the Metsähovi antenna reached its 20 year
mark during the year 2000. Observations of the main list with some 85
sources were continued through the year, though the sampling at 37 GHz
suffered from the problems with that specific receiver. During the
year 2000 about 2750 individual quasar observations were done. About
half of those were done in an automated mode. The observers in order
of number of observations were: H. Teräsranta, J. Virtanen,
P. Koivisto, T. Niemelä, J. Hänninen, J. Torppa, M. Koskimies,
M. Tornikoski, S. Wiren and A. Lähteenmäki and their share from
the total observations ranged from over 30
to under 0.2. The
observers come from University of Turku (6), Helsinki University of
Technology (3) and Helsinki University (1). In Figure 17 is shown the flux density of the Seyfert Galaxy 3C 120 from
1981 to the end of 2000 at 37 GHz as observed at Metsähovi.
The first phase of the search for new flat spectrum sources was
completed and the source list was updated. From the year 2001 the
source list consists of sources with a flux higher than 0.5 Jy at 22
GHz on average, spectral index higher or equal to 
between 4.8 and
22 GHz, source declination between 0 and +75 degrees and distance from
the galactic plane more than 20 degrees. Some additional sources,
mostly Northern gamma-ray detected sources are still in the source
list, even they don't satisfy all those 4 items mentioned above. The
new sample should be observed with a monthly sampling for all sources
at both 22 and 37 GHz. The main objective for the new sample is to
study the duty cycle of the sources which are most probably detected
by the next generation gamma-ray observatories AGILE and GLAST. As
all the gamma-ray detected AGN have also flat spectrum up to
millimeter frequencies, this sample with additions from the gamma-ray
observatories detections, would hold in it the strongest foreground
source s for the cosmic background explorer PLANCK. The successful
running of this monitoring project would require most of the observing
time of the Metsähovi radio telescope during the next years.
Co-operation with several research groups continued also during this year.
