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hd97048 radial extension

PostPosted: Tue Jun 30, 2020 4:06 pm
by bnorfolk
Hi,

I'm getting some significant radial emission on the reduction of hd97048 (cucha) from the 30 aug 2014 track contrary to what was published in van der Plas 2017. Here's my reduction steps:

1. No seemon values flagged

2. BPcal 1253-055
- blflag on spread between 18h06m – 18h20m 33/35 GHz
- flagged ant 6 on 33ghz
- MFcal int=0.1
- 5.698Jy measured

3. Gpcopy
- bpcal sol onto phasecal
- bpcal sol onto fluxcal

4. Fluxcal 1934-638
- flagged deviating amp vs time
- MFcal int=0.1 options=nopassol

5. Phasecal 1622-253
- Flagged ant 5 35ghz
- flagged all obs from -03:00:00 to 05:30:00 given deviation
- I flux 3.262
- MFcal int=0.1 options=nopassol

6. GPboot
- time(05:30:00,06:00:00)

Now in this reduction I've carried out significant flagging in an attempt to remove the radial emission with no success. Also, I understand I've significantly flagged most of the phase cal, I did this to try and remove the radial emission - obviously this didn't work. Previous reductions with less flagging on the phase cal produced the same results.

As I reduce my obs I scan the BPcal, fluxcal, and phasecal chan vs amp, time vs amp, and time vs phase plots. But they all seem to be within reasonable values. I've attached all relevant figures in a zip folder.

Any advice would be greatly appreciated.

Cheers,
Brodie

Re: hd97048 radial extension

PostPosted: Tue Jun 30, 2020 7:01 pm
by Mark.Wieringa
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. Their peak flux value is a bit higher as well, which would come with better calibration. Their image is cropped almost to the point where the partial ring that shows up in your version would be invisible. You could try cleaning you image a bit further, but you may need to improve the calibration first. That said, your calibration plots look fine to me and there are no obvious phase error patterns in the image - but this can be hard to tell with more extended sources.

Cheers,

Mark

Re: hd97048 radial extension

PostPosted: Wed Jul 01, 2020 2:16 pm
by bnorfolk
Thanks for the reply Mark.