More Sensitive Ground Telescopes

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More Sensitive Ground Telescopes

If a lower data rate were used, the number of detectable sources could be increased substantially by using a large ground telescope as an anchor. For instance, the Green Bank Telescope (GBT) is expected to have an SEFD of tex2html_wrap_inline356 Jy, compared to the value of 4200 Jy assumed for a VLBA telescope. Use of the GBT thus would reduce the detection threshold by a factor of tex2html_wrap_inline458. In the Southern Hemisphere and near the equator, the more sensitive phased Millimeter Array could be used. Table 4 illustrates the potential number of sources that could be detected, given a telescope with GBT sensitivity in the Northern and Southern Hemispheres. Since the telescopes mentioned here will not be dedicated to VLBI, they probably will not be available for a large fraction of their time with ARISE. Instead, they would more likely be used for occasional highly rated observations of weak sources at 86 GHz.

Table 4. Detectable 86-GHz Sources using GBT Baseline
Assumed tex2html_wrap_inline460 K
Data Rate (Gbit sectex2html_wrap_inline346) Detection Threshold Number
8 26 mJy > 1000
4 37 mJy > 1000
2 52 mJy > 500
1 74 mJy > 300


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