WMAP extragalactic point sources as potential Space VLBI calibrators
  The point source list of the Wilkinson Microwave Anisotropy Probe (WMAP) is a
uniform, all-sky catalogue of bright sources with flux density measurements at
high (up to 94 GHz) radio frequencies. We investigated the five-year WMAP list
to compile a new catalogue of bright and compact extragalactic radio sources to
be potentially studied with Very Long Baseline Interferometry at millimeter
wavelengths (mm-VLBI) and Space VLBI (SVLBI). After comparing the WMAP data
with the existing mm-VLBI catalogues, we sorted out the yet unexplored sources.
Using the 41, 61 and 94 GHz WMAP flux densities, we calculated the spectral
indices. By collecting optical identifications, lower-frequency radio flux
densities and VLBI images from the literature, we created a list of objects
which have not been investigated with VLBI at 86 GHz before. With total flux
density at least 1 Jy and declination above -40 degree, we found 37 suitable
new targets. It is a nearly 25% addition to the known mm-VLBI sources. Such
objects are also potentially useful as phase-reference calibrators for the
future Japanese SVLBI mission ASTRO-G at its highest observing frequency (43
GHz). The phase-referencing capability of ASTRO-G would allow long integrations
and hence better sensitivity for observing faint target sources close to
suitable phase calibrators in the sky.
