Region selection in cgdisp

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Region selection in cgdisp

Postby bnorfolk » Wed Jun 19, 2019 5:38 pm

Hi again,

Quick question, more of a confirmation. I'm zooming in to my region of interest in cgdisp using the box method, I'm looking at a protoplanetary disk so it's very small. The region documentation on miriad says for the arcsec option "the coordinates are in arcseconds, relative to the reference pixel". Does this mean that my region (where the size is defined by my box input) will be centred on the reference pixel, where this reference pixel is (in RA and DEC) what I pointed the telescope at during the observations?

Cheers,
bnorfolk
 
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Re: Region selection in cgdisp

Postby ste616 » Fri Jun 21, 2019 10:08 am

Hi Brodie,

No, it just means you specify offsets with regards to the reference pixel.

So, region=arcsec,box(-10,-10,10,10) will be a box 20 arcseconds on a side, centred on the centre of your field. But region=arcsec,box(10,10,30,30) will be the same box centred 20 arcseconds away from the field centre in each of the RA and Dec directions.
cheers
Jamie Stevens
ATCA Senior System Scientist
ste616
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Re: Region selection in cgdisp

Postby bnorfolk » Fri Jun 21, 2019 10:50 am

Makes sense, thanks

And the centre of field is the RA and DEC the telescope was pointed at?
bnorfolk
 
Posts: 31
Joined: Fri May 17, 2019 3:56 pm

Re: Region selection in cgdisp

Postby ste616 » Fri Jun 21, 2019 11:51 am

Yes.
cheers
Jamie Stevens
ATCA Senior System Scientist
ste616
Site Admin
 
Posts: 211
Joined: Thu Feb 04, 2010 3:27 pm
Location: Paul Wild Observatory Narrabri NSW


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