Observe File: SiO spectral line (thermal) and continuum

Here are observations of thermal SiO in W75N, as well as 43 GHz continuum of the same source. Fast switching is applied.

Observing strategy:
  • Start with a tipping scan to determine zenith opacity
  • Go to the flux calibrator 3C286 and do an X-band pointing scan
  • Observe 3C286 at Q-band in continuum mode
  • Observe 3C286 at Q-band in spectral line mode
  • Observe spectral line part:
    1. Go to a strong source close to the bandpass calibrator and do an X-band pointing
    2. Go to the bandpass calibrator 2012+464 and observe (spectral line mode)
    3. 2012+464 is also used as phase calibrator, make a fast switching scan of 40 minutes switching between the source W75N and 2012+464. Cycle time 140 sec (85 on target/55 on calibrator)
  • Repeat those steps 7 times. By repeating shorter scans we can update the pointing and allow for Doppler corrections to be made (which is only done at the beginning of each card)
  • Observe continuum part:
    1. Go to a strong source close to the bandpass calibrator and do an X-band pointing
    2. Observe 2012+464 (phase calibrator)
    3. Make a fast switching scan of 40 minutes switching between the source W75N and 2012+464. Cycle time 140 sec (85 on target/55 on calibrator)
  • Repeat those steps 4 times.
  • Do a pointing scan on another flux calibrator (3C48).
  • Observe 3C48 in continuum mode
  • Observe 3C48 in spectral line mode

This is the resulting observe file. Parts of the file are marked in color, with explanations below. These are things you need to look for in your observe file, to make sure the schedule is correct.

/.DSTST  2160                                                                   
//* *** 
//* *** NRAO VLA Observe Program,  Version U4.0.5, 1999.01.06
//* *** 
//* *** Observation day 58,371 at 15 00 00 LST, 2000.04.24 00:59:49 MST.
//* *** 
//* *** Observer
//* *** Debra Shepherd                                       Phone
//* *** NRAO/AOC                                    Office: 835-7398       
//* ***                                 During observation: 835-7398 
//* ***                         
//* *** 
//* *** E-Mail address
//* *** dshepher@nrao.edu                                           
//* *** 
//* *** Observing mode(s): line and continuum 
//* *** 
//* *** Special Instructions
//* *** Observe file for Q-band antennas only in subarray 1.        
//* *** SiO line  observations will run between 15:00 and 22:15 LST
//* *** Continuum observations will run between 22:15 and 02:00 LST
//* *** 
//* ***  Date Prepared: 2000.04.14 09:44:27 MST.
//* *** 
QTIPD         15 19 30 21 20 00.0000 +60 00 00.000C    QQ TE    0000            
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
1331+305      15 25 03 13 31 08.2882 +30 30 32.960C    XX IAA   0000   5.23     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
1331+305      15 35 02 13 31 08.2882 +30 30 32.960C    QQ   A   0000T  1.49     
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
1331+305      15 45 24 13 31 08.2882 +30 30 32.960C    QQ   A   2222T  1.49     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          205.961539                              
2007+404      15 52 00 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      15 57 38 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          16 43 15 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      16 46 22 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      16 52 00 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          17 37 38 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      17 40 47 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      17 46 32 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          18 32 05 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      18 35 15 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      18 41 06 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          19 26 48 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      19 29 57 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      19 35 48 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          20 21 47 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      20 25 42 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      20 31 37 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          21 17 34 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      21 20 59 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      21 26 50 20 12 05.6373 +46 28 55.787C    QQ   B   2222T  1.50     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000                              
W75N          22 12 29 20 38 36.5000 +42 37 33.500C    QQ       2222T           
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISVTL            10.000              10.000    43423.760000   43423.760000   
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      22 15 37 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      22 16 50 20 12 05.6373 +46 28 55.787C    QQ   B   0000T  1.50     
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
W75N          23 02 37 20 38 36.5000 +42 37 33.500C    QQ       0000T           
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      23 05 44 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      23 06 53 20 12 05.6373 +46 28 55.787C    QQ   B   0000T  1.50     
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
W75N          23 52 33 20 38 36.5000 +42 37 33.500C    QQ       0000T           
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      23 55 43 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      23 56 48 20 12 05.6373 +46 28 55.787C    QQ   B   0000T  1.50     
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
W75N          00 42 29 20 38 36.5000 +42 37 33.500C    QQ       0000T           
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
2007+404      00 45 42 20 07 44.9448 +40 29 48.604C    XX IAA   0000   2.85     
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
2012+464      00 46 45 20 12 05.6373 +46 28 55.787C    QQ   B   0000T  1.50     
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
W75N          01 31 26 20 38 36.5000 +42 37 33.500C    QQ       0000T           
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
//OF   NOD SKY         20 12 05.6373 +46 28 55.787              85  55          
0137+331      01 38 47 01 37 41.2995 +33 09 35.134C    XX IAA   0000   3.25     
//AN                                                                  ADL       
//DS            10                                                              
//LO     13.4   13.4      3940      3890                                        
//FISF              100.000000          200.000000                              
0137+331      01 49 13 01 37 41.2995 +33 09 35.134C    QQ   A   0000T  0.64     
//DS            10                                                              
//LO     51.6   13.0      3690      3740              0000                      
//FISF              100.000000          200.000000                              
0137+331      01 59 35 01 37 41.2995 +33 09 35.134C    QQ   A   2222T  0.64     
//DS 1A          3   0   000                                                    
//LO     51.9   13.0      3510      3510              0000                      
//FISF              110.430000          210.430000
21 20 00.0000 For a tipping scan this is the azimuth (in degrees) at which the tip should be performed. The important thing here is to avoid shadowing in the compact C and D configurations.
+20 00 00.000 The Dec determines whether the tip is done from low to high elevation, or from high to low elevation. Close to 23 degrees means from low to high elevations, while nearer to 55 degrees means the pass goes from high to low elevations.
TE This defines a tipping scan (set by specifying "Tipping scan" in the OBSERVE Source Page).
XX XX defines the observing frequency. Since this is a pointing scan, it should be in X-band.
IA This defines a referenced pointing scan with IF A (set by specifying "Det. ref. point." in the OBSERVE Source Page).
10 The integration time in seconds. Make sure this is 10 for your pointing scan.
T This T shows that you are applying the pointing corrections to the observing scan (set by specifying "Referenced Pointing" in the OBSERVE Source Page).
2222 Defines the bandwidth code for the 4 IFs, here 12.5 MHz
1A Defines the correlator mode; 1A means single IF spectral processing on IF A.
//OF NOD SKY Fast switching is determined by this 'off-set' card in 'NOD SKY' mode
20 38 36.5000 +42 37 33.500 RA and Dec of the first source in the fast switching cycle (here the target source). Note that in spectral line mode you want to have the first source in the cycle to be your target, since OBSERVE will Doppler track on the first source in this card.
20 12 05.6373 +46 28 55.787 RA and Dec of the second source in the fast switching cycle (here the calibrator)
85 55 The amount of time spent on the first and second source in the fast switching cycle (85 sec and 55 sec respectively). Move time is included.
VTL Important for spectral line: the //FI card defines the Fluke synthesizer frequencies. V stands for velocities according to the radio convention and that you define a rest frequency in addition to velocity of the source; T stands for center frequency reference and finally L for an LSR rest frame. If you are observing extragalactic targets you probably want to have "ZTB" instead of "VTL", where Z stands for optical velocity convention (and that you define a rest frequency in addition to velocity of the source), T as above and B for a barycentric rest frame.
10.000 Fluke A and B velocities in km/s - the velocity of your target.
43423.760000 43423.760000 Fluke A and B line rest frequencies in MHz - the line rest frequencies.
Modified on Friday, 26-Sep-2008 12:09:06 MDT by Ylva Pihlström