Cyber Meetings FY2022 for
CASA tutorial | wSMA
 

Time -

  • Time: March 29, 2022 at 10 am to 11 am EDT

Cyber link -

Agenda -

  • Introduction -
    • Beth:
    • 1. Primary goal -
      • My goal with my SMA data is to be able to output the final spectrum for my science targets.
    • 2. Issues -
      • I think we are close to being able to do that in CASA, so I was hoping you could show me how to do that.
      • The other issue is that I was running the script you gave me in early December last night, and it worked for 2 of the sources, but for the other 2 sources, it didn't work correctly. As far as I know, the script you gave me in January did seem to work for all 4 sources.
    • Email communication on March 21, 2022
JHZ:
  • 2. Demo (continue from 2021-12-15) -
    • share screen
    • login to RTDC9
    • goto /reduction/jzhao/SMA2CASA_TESTING/Users/BethSargent/im_inspec/
    • start casa (5.8)
      • run IRAS17439imInspec.py (done on 2021-12-15)
      • module 0: a summary of tasks
      • module 1: convert FITS to CASA
      • module 2: inspect image header
      • module 3: viewer and inspect image cube
      • module 4: viewer and inspect a specific image plane (chan 100)
      • module 5: make statistics
          • Online demo -
        • FITS: J154546COcube2.fits
          • cp IRAS17439imInspec.py J154546COcube2imInspec.py
          • edit line 46, replacing IRAS17439 with J154546COcube2
        • run J154546COcube2imInspec.py


        • FITS: SCHB_145COcube.fits
          • cp IRAS17439imInspec.py SCHB_145COcubeimInspec.py
          • edit line 46, replacing IRAS17439 with SCHB_145COcube
        • run SCHB_145COcubeimInspec.py

          • Get the python scripts -
        • Click here for wget instruction

          • Demo to get a spectrum from an image cube -
        • start CASA (5.8)
            • Assuming the relevant FITS imagecube has been imported to CASA - 
              CASA <4>: run J154546COcube2imInspec.py 
You are in casapy.
Excute current task                   0
Import FITS image                     1
Check the image header                2
View the image cube                   3
View the channel image 100            4
Make statistics on channel image 100  5
Which step do you take?                
> 3
move cursor to the top tab of CASA Viewer, click the icon: View, 
and then move to the icon Animators and click it
          • Pause at the channel 126 or at -735.627 km/s
          • Choose an emission area (See Fig. 1)
          • Click the spectrum icon, and then a spectral plot pops up (see Fig. 2)


















          Fig. 1: Channel 126 image of the cube J154546COcube2.tt0. The ellipse outlines the line emission area at this channel.

























          Fig. 2: The spectrum extracted from the cube J154546COcube2.tt0 for the elliptical area outlined in Fig. 1. The vertical lightblue line corresponds to the spectral feature seen in Fig. 1.