SUGGESTIONS ON PROPOSING FOR VSOP OBSERVATIONS

Many new proposals for HALCA will be associated with previous VSOP and other VLBI observations, since we anticipate the continued monitoring of many of the brightest radio sources. Results from these previous observations will be important in determining the scientific merit of additional VSOP observations. Please include references to all previous VSOP and other VLBI observing codes. The list of all successful AO1 and AO2 VSOP observations and those scheduled through the middle of 2000 are given below. Please use this list to determine the best continuation of VSOP monitoring observations as well as proposing for other sources.

Your proposal may also be associated with concurrent VLBI proposals. For example, you may be proposing for ground VLBI observations at 15 GHz to complement VSOP observations at 5 GHz. Please indicate such connections clearly in your proposal since refereeing of these ground and VSOP proposals should be made in a coordinated way. All such complementary ground-only observations must be proposed independently to the appropriate ground array, even if it is intimately related to a VSOP proposal. As an example, if you propose for a source at 5 GHz using HALCA, but also wish to observe at 15 GHz with a ground array (even during the VSOP observation period), a separate proposal must be submitted to that ground array.

Although we anticipate that most proposals will be for active galaxies, proposals for the OH line (all four lines), pulsars and the brighter radio stellar objects are invited.

The specification of the ground resources for your experiment is not necessary, but can be included especially for non-standard experiments. It is important to specify the need for big ground telescopes if the correlated flux density with the HALCA observations is expected to be less than (or measured in previous experiments) about 0.1 Jy, or if the science goals of the observation require the additional sensitivity. The available time on these large telescopes is limited and must be used judiciously.

You should concentrate on proposing for sources which are in those regions of sky which can be observed during the January to May 2000 period. For some areas good (u,v) coverage may not occur again for another year, or even two years. Proposals for all regions of the sky will be accepted and reviewed. However, proposers should keep in mind that proposals that are not scheduled within a year may have to be reproposed.

The regions of sky which should be proposed for this deadline are given below:

         AREAS OF THE SKY WHICH CAN BE BEST OBSERVED
           WITH HALCA BETWEEN JANUARY TO MAY 2000

        Declination Range      Right Ascension Range
                (degrees)      (hours)

                65 to  90      09 to 15
                45 to  65      07 to 17
                 5 to  45      05 to 17
                -5 to   5      05 to 15
               -15 to  -5      03 to 15
               -25 to -15      03 to 13
               -35 to -25      03 to 09
               -90 to -35      03 to 11

Inclusion of (u,v) coverage plots is not needed for your VSOP proposal. The observations will be scheduled with the best (u,v) (generally highest resolution with reasonable two-dimensional coverage), consistent with the scientific rating and the allotment of resources. However, recommendations of specific observing times, (u,v) coverages, and ground resources will be used if possible. The proposer should give some consideration of the changing (u,v) coverage and source observation availability when asking for source monitoring observations.

Use the plots of monthly (u,v) coverage available from the VSOP WWW site. For more detailed analysis please use the latest version of one of the simulation software packages. However, for most proposals the tables of (u,v) coverage may be sufficient for planning of your observation.