The ATCA Forum

Hi Mark, I've tried to flag the shadowed data and the second 1934 scan as you suggested, but it seems that there are still ~3 "wild" points in 1934's uvplt: 1934-638_uvplt.png And 0023-263 doesn't look good either: 0023-263_uvplt.png While I don't know what's going on, I wonder if I can fl...

Hi Mark, I've been thinking about the uvplt of the two calibrators. Even in the uvplt of the raw visibilities before any flagging/calibration, I still couldn't see any region on the real-imag plane which might become disks/ellipses afterwards. The data just look similar to the uvplt that I've shown,...

Hi Mark, I've gone through all the flagging & calibrations and the imaging clean process, and the cleaned map looks like below. Although the map looks not too noisy, only few number of sources are detected (using sfind task, 11 sources are detected), compared to previous 5 GHz map in which 61 so...

Hi Mark, The dirty map looks better after I excluded the shortest baseline, supposedly ant(1)(2). However, uvplt of both 1934-638 and 0023-263 still show an "arc", similar to those I showed, after I did more flagging and shorten interval=3 (was 5). I am wondering what might be the appropri...

Hi Mark, It seems that I used the wrong calibrators. I'm trying on G018 now, another source which had fewer problems in the 5GHz data, so presumably I should use 0023-263 as the phase calibrator and 1934-638 as still the bandpass calibrator? I did flagging and calibration again following the link we...

Hi Mark, Thanks for the suggestions. When I tried uvaver on the source data, only a "header" and a "history" files were present in the output, but no any calibration file or visdata... What are the suggestive ways to make plots and check the calibration? Thinking of blflag and uv...

Hi, I am trying to reduce the raw data of one of our sources at 9GHZ (See https://atcaforum.atnf.csiro.au/viewtopic.php?f=21&t=270). Following instructions from the ATCA data analysis webpage, I used "pgflag" to do the flagging on this source. However, it seems to take forever in this ...

Hi Mark, Thanks for the suggestion, It turns out that it's the "rmsbox" which I set it too large... But if I set rmsbox the default value (20 pixels), it works for one of our sources (G345) but not for the other (G018). For G018, miriad returns an error message "### Fatal Error: No co...

Hi, I am trying to produce a noise map with one of our 5.5GHz continuum observations. There is a sfind.rms image produced after the miriad task sfind to detect sources, but that map just has a constant value over the whole image (for all rmsbox values I tried: 50, 1000, 5000, 10000, 23494); also, th...

Hi Mark, It turns out to be a further improvement (attached). But I still couldn't figure out that there's still some difference. Is it only the scaling is different? Or the weighting scheme is different? (I'm using robust=0 throughout all imaging; robust=0.5 is a bit noisier.) Or the selfcal clip i...