The ATCA Forum

Hi Joe,

sorry for the late reply, somehow I didn't get notified.
I've just installed a new version of miriad that fixes the problem (at least for me).

Cheers,

Mark

Hi Brodie, All these options used to work ok, although I've never made the kind of plot you have. Some possible causes of difference are * calibration: you need to apply this to the data before exporting to fits or importing with importmiriad; * weighting - default weights are integration time, you ...

Hi Brodie, if you have poor uv coverage, using channelised data will help fill the uv plane using multi frequency synthesis. If you average first, you loose this extra coverage. The poor SNR might just be due to higher sidelobes in the averaged data. The actual theoretical noise level should be the ...

Hi Brodie, Unfortunately I don't have much to offer here. There was an attempt to get the Miriad opacity code into CASA 5 years ago, but it doesn't look like it is easily accessible from the user level. The atcafiller tool has an opacities function, but I'm not sure how to get the corresponding Tsky...

Hi Brodie, I think this question might be a bit beyond what we can answer. The article states that radial structures were noticed in the Aug 31 track, which had poor phase stability, so if you are getting some of these effects in the data for the 30th, it may be a similar issue, i.e., phase errors. ...

Hi Yihan, The fwhm specified in invert is a taper applied to the data, it does not directly specify the resulting beam size, as this depends on the details of the configuration and observing time. It is unusual for the beam to be smaller than the fwhm specified for the taper, it is usually a bit lar...

Hi Tim,

thanks for reporting this.
I must admit I don't quite understand what the code is trying to do here, but I slapped on a patch and now it exits when there is no unflagged data left.
Let me know if you notice any other issues.
The update should go out tomorrow night.

Cheers,

Mark

Hi Yihan, The task psrfix can be used to correct for dispersion or a wrong period, however you do need to know and enter the correct values - it doesn't figure them out for you. Maybe https://www.atnf.csiro.au/research/pulsar/psrcat/ can be of use here. I'm afraid you've reached the limit of my know...

Hi Yihan, interesting question! I'm no expert on pulsar processing, but the stripes seem to indicate that you may have used a slightly wrong pulse period for the pulsar binning. This would cause the pulse to shift through the phase binned images with time and only show up for a short time in each im...

Hi Rami,

I think the best way is to compare different sources.
Circular polarisation is rare, so if all sources have a small but similar percentage V it is likely to be leakage, but if one source stands out it is probably real.

Cheers,

Mark