Title  Magnetic field geometry in protostellar envelopes
Pi     J. Richer
Time   112 hrs


 1. Name: Magnetic field geometry in protostellar envelopes

    Authors: J Richer

 2. Science goal: Make images of linearly polarised dust emission in the
    envelopes of protostars to constrain role of magnetic fields in
    star formation. 

3. Number of sources: 4

4. Coordinates: 

  4.1. 2 sources in Oph      (RA=16:30, DEC=-24)
       2 sources in Taurus (RA=03,  DEC=+30)

  4.2. Moving target: no

  4.3. Time critical: no

5.  Spatial scales:

  5.1. Angular resolution: 1.0"
       
  5.2. Range of spatial scales/FOV: 20 arcsec

  5.3. Single dish: yes
 
  5.4. ACA: yes

  5.5. Subarrays: no
 
6. Frequencies:

  6.1. Receiver band: Band 7

  6.2. Line: Not important but most likely HCO+ 4-3 at 357GHz

  6.3. Spectral resolution (km/s): 0.1 km/s
  
  6.4. Spectral coverage (km/s or GHz): 20 km/s    


7. Continuum flux density:

  7.1. Typical value: 10 mK

  7.2. Continuum peak value: 

  7.3. Required continuum rms: 130 micro K

  7.4. Dynamic range in image:


8. Line intensity:

  8.1. Typical value: N/A

  8.2. Required rms per channel: N/A
  
  8.3. Spectral dynamic range: N/A

9. Polarization: yes - critical

10. Integration time per setting: 4 sources x 7 pointings per source
    x 240 minutes per pointing

    In 4 hours one reaches 130 micro Kelvin of brightness sensitivity.
    In the inner parts (<1000 AU) of the envelope one expects emission
    at the level of about tens of mK and stronger (using a simple 1/r^2
    isothermal envelope model). Thus one can detect few % polarisation
    at the several sigma level, which is just about good enough.  This
    is very model dependent of course. 

11. Total integration time for program: 112 hr

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Review Munetake Momose: OK.
--------------------------------------------------
Review v2.0:
 
yso_2 = 2.2.2

1. Name: Magnetic field geometry in protostellar envelopes

    Authors: J Richer

Unchanged w.r.t. DRSP 1.1. Obvious project and calibration will be
hell. Are the cross-correlation between the 7m and 12m antennas also
useful, or would they only add to calibration-hell?