Program: Using ALMA to probe active regions in Sun like stars
PI:  G. Hussain
Time: 60 hrs

2. One short paragraph with science goal(s)

Using the polarization capabilities of ALMA, we will measure the magnetic fields in flaring coronal loops. These measurements will provide key information about the sizes of stellar coronae and their geometries.  These observations will constrain 3D coronal models.  We request observations of six nearby active stars over 10 hour timeperiods to follow the evolution of flares.

3. Number of sources 
   
Six nearby active stars

4. Coordinates:

4.1. Rough RA and DEC  unknown

4.2. Moving target: no 

4.3. Time critical: yes (?)

4.4. Scheduling constraints: none


5. Spatial scales:

5.1. Angular resolution (arcsec): 0.1''

5.2. Range of spatial scales/FOV (arcsec):  10''


5.3. Required pointing accuracy: (arcsec)  N/A


6. Observational setup

6.1. Single dish total power data: no

     Observing modes for single dish total power: 


6.2. Stand-alone ACA: no

6.3. Cross-correlation of 7m ACA and 12m baseline-ALMA antennas: 
     no

6.4. Subarrays of 12m baseline-ALMA antennas: no


7. Frequencies:

7.1. Receiver band: Band 3, 4, 5

7.2. Lines and Frequencies (GHz): 
100,150, 190

7.3. Spectral resolution (km/s): N/A

7.4. Bandwidth or spectral coverage (km/s or GHz):   8 GHz


8. Continuum flux density: ?

8.1. Typical value (Jy): ?

     (take average value of set of objects)
     (optional: provide range of fluxes for set of objects)

8.2. Required continuum rms (Jy or K): 0.1 mJy

assuming the full 8 GHz bandwidth:

at 100 GHz, to get the required rms, it would take 27 seconds on source
at 150 GHz, to get the required rms, it would take 46 seconds on source
at 190 GHz, to get the required rms, it would take 22005 seconds on source
(since there are only 5 antennas with band 5 receivers)

8.3. Dynamic range within image:  ?


8.4. Calibration requirements: absolute      ( 1-3% / 5% / 10% / n/a )
                               repeatability ( 1-3% / 5% / 10% / n/a )
                               relative      ( 1-3% / 5% / 10% / n/a )


9. Line intensity:  NA

9.1. Typical value (K or Jy):

     (take average value of set of objects)
     (optional: provide range of values for set of objects)

9.2. Required rms per channel (K or Jy):

9.3. Spectral dynamic range:

9.4. Calibration requirements: absolute      ( 1-3% / 5% / 10% / n/a )
                               repeatability ( 1-3% / 5% / 10% / n/a )
                               relative      ( 1-3% / 5% / 10% / n/a )


10. Polarization:yes

10.1. Required Stokes parameters:  ?

10.2. Total polarized flux density (Jy):

10.3. Required polarization rms and/or dynamic range:

10.4. Polarization fidelity:

10.5. Required calibration accuracy:


11. Integration time for each observing mode/receiver setting (hr):

10 hours per source (6 sources)
at 100 GHz, the sample rate could be as high as a minute?
at 150 GHz, the sample rate could be as high as 90 seconds?
(do they have to have the same time resolution? because then the 
rms noises would be different)

12. Total integration time for program (hr): 60 hr 


13. Comments on observing strategy : (optional)

    (e.g. line surveys, Target of Opportunity, Sun, ...):