EVN User Experiment Pipeline Feedback


Pipeline feedback for experiment EP044. If you have any comments on this experiment please email the address below.
A detailed description of the pipeline output is available.

Last updated: Mon May 24 15:04:22 CEST 2004 biggs@jive.nl

General Comments. ( Brief data summary and scan listing )
This is an EVN-only imaging experiment at 1.3cm (single polarisation - LCP, 4 IFs). Particpating stations were Ef, Jb (Mk2), Mc, Nt, On, Mh, Cm, Ur and Sh. Mc and Ur could not be correlated due to frequency setup problems. The reference antenna for calibration was Ef and that for plotting Jb. The EVN reliability indicator was ERI=0.40 (Ef=0.92, Jb=1.00, Mc=0.00, Nt=1.00, On=1.00, Mh=0.5, Cm=0.5, Ur=0.00, Sh=1.00). ERI gives you an estimate of the ratio of observed/good visibilities to the expected number. ERI* is the same, but excludes data lost due to circumstances out of the EVN's control e.g. bad weather (ERI*=0.40).

Plots of the autocorrelations .
Comments.
Sh and Cm miss a couple of these scans.
Mc: IFs 2 and 3 have no data.
Cm: IFs 3 and 4 have no data whilst IF2 has had most of the upper channels flagged (microwave link in both cases).

Plots of the uncalibrated amplitude and phase against time .
Comments.
Last scan appears to be very noisy.
Mh: one scan in IF2 has survived. This should be closely checked for the presence of real signal.

Plots of the uncalibrated amplitude and phase against frequency channel .
Comments.
None.

The uncalibrated amplitude and phase of the crosshand correlations against frequency channel (not available) .
Comments.
n/a.

TSYS against time .
Comments.
Mh: Tsys show a bimodality for the first half of the experiment.

Telescope sensitivities from the a priori TSYS and Gain curves (the square of this number gives the antenna noise (SEFD) in Jy - the smaller the better).
Comments.
Gains for most of the telescopes are calibrated accurate to about 20% (according to the EVN Status Table). Jb, Cm and Sh though appear to have greater sensitivites than expected, but a factor of 4 in the case of Sh!

Fringe-fit phase solutions (including Parallactic Angle correction).
Comments.
Phases wrap very quickly to all antennas.
Ef: variation reflects parallactic angle.
Note that no solutions have been found to Cm in IF2 and to the small amount of data that remained in IF2 of Mh.

Fringe-fit delay solutions .
Comments.
None.

Fringe-fit rate solutions .
Comments.
None.

Telescope bandpasses .
Comments.
None.

Calibrated amplitude and phase against time (a priori amplitude calibration and fringe-fit solutions applied).
Comments.
None.

Calibrated amplitude and phase against frequency channel .
Comments.
None.

Naturally weighted dirty map produced before self-cal of:
1849+670 .
J0102+58 .
J0136+47 .
Comments.
None.

Uniformly weighted dirty map produced before self-cal of:
1849+670 .
J0102+58 .
J0136+47 .
Comments.
None.

Phase corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
1849+670.
J0102+58.
J0136+47.
Comments.
None.

Amplitude corrections applied to a priori calibrated and fringe-fitted data by self-calibration.
1849+670: postscript , or text file .
J0102+58: postscript , or text file .
J0136+47: postscript , or text file .
Comments.
Solutions are noisy and not, in general, consistent between sources. Some corrections do seem to be made that agree with the differences seen between the gain values (above) and the EVN status table. Amplitude correction factors for Sh, however, are not ~4.0. This antenna is probably not well constrained in the fit although the Status Table might be in error. Solutions for On though are consistently below unity though, as expected.

Telescope sensitivities (the total AMP gain applied during both a priori and self calibration; the square of this number gives the antenna noise (SEFD) in Jy).
Comments.
Sensitivities of Jb and Cm do seem to agree better now with the EVN status table.

Residual closure phase (visibility closure phase with model closure phase subtracted) for:
1849+670 .
J0102+58 .
J0136+47 .
Comments.
None.

Calibrated visibilities and the source model of:
1849+670 .
J0102+58 .
J0136+47 .
Comments.
None.

Calibrated visibilities against u,v distance for:
1849+670. postscript , or png (smaller)
J0102+58. postscript , or png (smaller)
J0136+47. postscript , or png (smaller)
Comments.
None.

u,v coverage for:
1849+670. postscript , or png (smaller)
J0102+58. postscript , or png (smaller)
J0136+47. postscript , or png (smaller)
Comments.
None.

Crude map of 1849+670 from the pipeline .
Crude map of J0102+58 from the pipeline .
Crude map of J0136+47 from the pipeline .
Comments.
Source is detected at the centre of each map. (You can zoom into the plot in Ghostview where about 5 contours can be seen for each source.)