EVN image sensitivity

Assuming a total data rate of 128 Mbits/sec (or a bandwidth of 64 MHz and 1-bit data sampling) and a total on-source observing time of 8 hours, the 1-sigma RMS thermal noise level (in microJanskys/beam) expected in maps produced by a typical EVN array is listed below:

(*) At 18 cm "EVN Array" == Eb, Jb-1, Cm, Wb, Mc, Nt, On-85, Tr, Sh, Ur
(*) At 6 cm "EVN Array" == Eb, Jb-2, Cm, Wb, Mc, Nt, On-85, Tr, Sh, Ur
(*) At 5 cm "EVN Array" == Eb, Jb-2, Mc, On-85, Tr, Hh
(*) At 3.6cm "EVN Array" == Eb, Mc, Nt, On-60, Sh, Ur, Yb
(*) At 1.3cm "EVN Array" == Eb, Jb-2, Cm, Mc, Nt, On-60, Mh, Sh, Ur

The numbers above have been calculated using the EVN Calculator.

Note that for very bright sources, with peak fluxes > 0.2 Jy, the effects of intrumental polarisation begin to dominate over thermal noise (at 18 and 6cm). In these cases, the thermal noise can only be reached by solving for the instrumental polarisation parameters first, the so called "D-terms". Bright sources will also be dynamic range limited.

Spectral-line experiments often use much smaller observing bandwidths since the lines are narrow and high spectral resolution is often required. In this case, the values listed in the table above must be multiplied by the square-root of the ratio of the bandwidths.