ASTE Wiki

Demo [CI](3P1-3P0) map of a star forming region RCW38 †

Last update
  • 2021-03-08 copyed from the ASTE Web site on Google.
Table of contents

Data archive

Data information

TargetRCW38
Observation date2016/11/26
ReceiverBand8
SpectrometerMAC
ModeOTF mapping
Frequency492.160656 GHz*
Bandwidth512 MHz (Wide Band mode)
Channel spacing0.5 MHz
Velocity resolution0.3 km/s
Beam size (FWHM)17 arcsec
Mapping size6 arcmin x 8 arcmin
Total mapping time~ 6 hrs
Tsys800 - 1400 K
PWV~ 0.5 mm
Opacity (220 GHz)0.02 - 0.07

CASA data reduction

Data reduction

  1. Baseline subtraction
    $ default(sdbaseline)
    $ sdbaseline(
        infile='R38otfX.RCW_38.20161126043008.4.ms',
        datacolumn='float_data',
        spw='0:350~470;560~650,1:350~470;560~650',             # 350-470 ch and 560-650 ch correspond to -46.44~-9.93 km/s and 17.45~44.84 km/s, respectively.
        blfunc='poly', order=1,                                # fit function to subtract baselines
        outfile='R38otfX.RCW_38.20161126043008.4.A1A2.bl.ms',
        overwrite=True)
  2. Scaling to convert Ta* to Tmb
    1. Making table for scaling
      $ default(gencal)
      $ gencal(
          vis='R38otfX.RCW_38.20161126043008.4.A1A2.bl.ms',
          caltable=‘R38otfX.RCW_38.20161126043008.4.A1A2.bl.mb.tbl',
          caltype='amp',
          parameter=[sqrt(0.45)])  # Main beam efficiency of 45 % is used. 
                                   # See the ASTE home page (https://alma.mtk.nao.ac.jp/aste/instruments/telescope.html).
    2. Applying the scaling table
      $ default(applycal)
      $ applycal(
          vis=‘R38otfX.RCW_38.20161126043008.4.A1A2.bl.ms',
          gaintable=['R38otfX.RCW_38.20161126043008.4.A1A2.bl.mb.tbl'],
          calwt=[False])
  3. Imaging
    $ default(sdimaging)
    $ sdimaging(
        infiles='R38otfX.RCW_38.20161126043008.4.A1A2.bl.ms',
                'R38otfX.RCW_38.20161126065817.4.A1A2.bl.ms',
                'R38otfX.RCW_38.20161126091618.4.A1A2.bl.ms'],
        outfile='R38otfX.RCW_38.20161126.4.A1A2.bl.int',
        intent='*ON_SOURCE*',
        gridfunction='GJINC',
        cell=['6arcsec','6arcsec'],
        mode='velocity', nchan=167, start='-49.7km/s',width='0.6km/s',
        overwrite=True,
        imsize=[60,80],
        phasecenter='J2000 08:59:05.78 -047.31.00.020')
    • We made two imaging data (Xscan and Yscan)
  4. Removing scanning effect (Basket-weave)
    $ default(sdfixscan)
    $ sdfixscan(
        infiles=['R38otfX.RCW_38.20161126.4.A1A2.bl.int',
                 'R38otfY.RCW_38.20161126.4.A1A2.bl.int'],
        direction=[0,90],
        maskwidth=[5.0,3.0],
        outfile='R38otfXY.RCW_38.20161126.4.A1A2.bl.int',
        overwrite=True)
  5. Making Fits file
    $ default(exportfits)
    $ exportfits(
        imagename='R38otfXY.RCW_38.20161126.4.A1A2.bl.int',
        fitsimage='RCW_38.20161126.4.CI.casa.fits',
        velocity=True,dropstokes=True)

Sample images

Acknowledgement and references in publications

Acknowledgement

References


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