Biennial Report 2003-2004 - Merlin

4
EVN data processor. The EVN has been at the
forefront of VLBI developments, transforming its
capabilities with new technologies. The EVN was
the first astronomy VLBI network to adopt the
new disk-based Mk5 recording system, developed
at Haystack Observatory. This capability, together
with the large radio telescopes at Effelsberg, Jodrell
Bank and Westerbork, make the EVN the
instrument of choice for high sensitivity VLBI. The
VLBI capabilities of the EVN are listed in Table 2.
Biennial Report 2003-2004
MERLIN/VLBI National Facility
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Table 1: Capabilities of MERLIN. Notes: (a) Five MERLIN antennas were equipped with new C-band receivers by the end of 2004. (b) The Lovell Telescope can be used instead
of, or as well as, the Mk2 telescope at Jodrell Bank at the lower frequencies. (c) Subject to a maximum dynamic range. This depends on source structure, declination and
u-v coverage, but is typically 10,000:1 (peak:RMS) for full track observations at the higher declinations. (d) Adverse weather conditions can significantly degrade the
performance, especially at the highest frequencies. (e) Inclusion of the Lovell Telescope reduces the RMS noise to ~ 35 μJy/beam.
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g t
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c m
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8
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/
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c
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3 10 19
E E V
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s i
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)
84 52 12 10 300 1000
Table 2: Capabilities of the EVN. Note that the EVN also observes at 30 cm, 3.6/13 cm and 7 mm but the National Facility telescopes are not equipped at these wavelengths.
The sensitivity estimates are from the EVN User Guide and assume 8 hours on source with 1 Gbit/second data rate (equivalent to 16 x 16 MHz with 2 bit sampling). The
92 cm and 49 cm values are based on these but scaled using estimates of the system performance and available bandwidth at these wavelengths.
Figure 2: The EVN Correlator is operated by the Joint
Institute for VLBI in Europe (JIVE), which is hosted by
ASTRON in Dwingeloo, the Netherlands.
6 b