The CARMA script writer produces a template observing script. In nearly all cases, the principal investigator will need to further edit the script for their observations, particular the correlator configuration and the tuning parameters.The required inputs for the script writer are:
A number of parameters can be specified to mosaics, passband, pointing, and flux calibration. If you are making a mosaic, then the mosaic parameters must be modified to enter at minimum the mosaic pointing offsets.
- Source name (up to 8 characters)
- Right ascension (hh:mm:ss.s, J2000)
- Declination (dd:mm:ss.s, J2000)
- Project code (assigned when proposal was submitted; e.g. c0010)
- obsblock for this track (e.g. 3B_HLTau)
- Contact information in case there are any questions regarding the observing script
Once the template script has been generated, it should be saved to an ascii text file and edited as necessary. The name of observing script should be projectCode_obsblock.obs (e.g. c0010_3B_230hltau.obs).
More detailed instructions on how to edit the script and where to send the scripts can be found on the script FAQ page.
Names of the contact person in case any questions arise regarding the script.
Email addresses for the contact person. In addition, an observing log will be set to each email address. Multiple email addresses should be separated by spaces or commas.
Examples:
pi@astro.univ.edu
pi@astro.univ.edu,coI@astro2.univ.com
Assigned project code for this track. The project code can consist only of alphanumeric characters (a-z, 0-9).
Example: c0012
Name of the obsblock for this observing script. The obsblock names will be sent to you by Nikolaus Volgenau. The obsblock can consist only of alphanumeric characters (a-z, 0-9).
Example: 1B_230hltau
Name of the source catalog containing the coordinates of the source. The catalog name can be an existing catalog, or the name of a new catalog you intend to create. The catalog must follow the CARMA catalog format, and should be sent along with the observing script. If the sources are in the standard CARMA system catalog, enter None.It is suggested that the source catalog be named projectCode.cat, where projectCode is the project code assigned when your proposal was submitted.
Example:
c0012.cat
Observing band (1cm, 3mm, or 1mm) for this project.
The observing semester in which the track will be run.
The source name(s) as it will appear in the catalog. Multiple source names should be separated by commas. Each source may contain at most up to 8 characters long. The source name cannot contain spaces, * symbols, or other unusual characters. HLTau,DLTau,0430-014
Right ascension in the format hours:minutes:seconds in epoch and equinox J2000. If there are multiple sources, then enter the right ascension for only once source. Example: 06:10:01.0
Declination in the format degrees:minutes:seconds in epoch and equinox J2000.
If there are multiple sources, then enter the declination for only once source. Example: +18:10:00
Velocity of the sources in km/s.
Indicates if a source will be mosaicked or not. If True, then the Mosaic Parameters section must be completed.If you have listed multiple science targets, then you should list True/False for each target. For example, if you wanted to mosaic NGC1333 and observe a test calibrator 0312+313 with only a single position, then you should specify the following: science target(s): NGC1333,0312+313
mosaic: True, False
If you know which phase calibrator you want to use, you can enter the name. Otherwise, a bright source near your object will be selected for you. There are several tools available to help you select phases calibrators. A calibrator list is available, as well as the Xplore graphical interface. See the section Integration time - phase calibrator for guidance on how bright the quasar should be for gain calibration. As a rough guide, you usually want a source brighter than 1 Jansky.
The minimum acceptable flux density in Janskys for the phase calibrator. As a rule of thumb, the phase calibrator should be brighter than 1 Jy within 20 degrees of the source. Sources with flux density as low as 0.5 Jy have been successfully as calibrators in good weather conditions.The calibrator flux density should be matched appropriately to the calibrator integration time. See the script FAQ page for further guidance on selecting calibrators and setting the integration time.
Total integration time per pointing on the source for each phase calibrator-source cycle.If you are observing a mosaic, then the integration time specified is per pointing in the mosaic. For example, if you are observing NGC1333 with a 15 point mosaic, and the test calibrator 0312+313 at a single position. You want to observe each position in the mosaic for 1 minute, and then the test calibrator for 3 minutes. You will then specify the following: science target(s): NGC1333,0312+313
mosaic: True, False
integration time - science target: 1, 3The source integration time determines how frequently the phase calibrator is observed. In general, the phase calibrator should be observed more frequently for longer baselines. A source integration time of 15 minutes is appropriate for C-array. See BIMA memo #70 for a discussion of the optimum time between phase calibrators.
Total integration time for each observation of the phase calibrator. The number of records will be given by the integration time divided by the record length.See the Script Writer FAQ for guidance on the required the integration time for your pass band source.
Rest frequency for the observations in GHz.
The I.F. (intermediate frequency) for the rest frequency in GHz. The valid range is between 1 and 9 GHz.
Sideband for the rest frequency. (USB for upper sideband, or LSB for lower sideband).
Enter the correlator configuration for the observations. This normally consists of 8 lines of the form:configband(1, BW500, 95.0),where in this example, 1 is the band number, BW500 is the desired bandwidth, and 95 (GHz) is the center rest frequency of the correlator band.Note:
An example tuning and correlator configuration for continuum observations is as follows:
- There should be a configband statement for all 8 correlator bands.
- The available bandwidths are BW500, BW250, BW125, BW62, BW31, BW8, and BW2.
- BW125 and BW250 are not currently available for bands 1, 2, and 3.
- A more complete desscription of the correlator bands is available at http://cedarflat.mmarray.org/observing/doc/instrument_desc.html.
- None of the correlator bands should overlap an IF frequency of 5.0 GHz.
tuning = { 'restfreq' : 95, # [GHz] Line rest frequency 'sideband' : USB, # Sideband for first LO (LSB or USB) 'IFfreq' : 3, # [GHz] IF frequency } configband(1,BW500,tuning['restfreq']-1.0) # IF = 2.0 GHz configband(2,BW500,tuning['restfreq']-0.5) # IF = 2.5 GHz configband(3,BW500,tuning['restfreq']) # IF = 3.0 GHz configband(4,BW500,tuning['restfreq']+0.5) # IF = 3.5 GHz configband(5,BW500,tuning['restfreq']+1.0 # IF = 4.0 GHz configband(6,BW500,tuning['restfreq']+1.5) # IF = 4.5 GHz configband(7,BW500,tuning['restfreq']+2.5) # IF = 5.5 GHz configband(8,BW500,tuning['restfreq']+3.0 # IF = 6.0 GHz
Name of the ascii file that contains the pointing offsets. A more detailed description can be found in the FAQ page.
Instead of providing a file, you can list the mosaic offsets directly. A more detailed description can be found in the FAQ page.
The units for the mosaic offsets. A more detailed description can be found in the FAQ page.
Number of mosaic positions to observe between phase calibrator observations. A more detailed description can be found in the FAQ page.
Indicates if a passband calibrator should be observed. In general, this should be True, unless the phase calibrator is bright enough to serve as a passband calibrator.
Total integration time in minutes on the passband source. The number of records will be given by the integration time divided by the sampling time. See the Script Writer FAQ for guidance on the required the integration time for your pass band source.
The minimum flux density in Janskys for the passband calibrator.
Comma-separated list of preferred passband calibrators, if any.
Indicates how frequently in hours to perform radio pointing at night.
Indicates how frequently in hours to perform radio pointing during the day.
Indicates how frequently in hours to perform optical pointing.
The minimum flux density in Janskys for the pointing source.
See the Script Writer FAQ page for more information on recommended radio pointing procedures.
The maximum allowed distance between the pointing source and the target.
Comma-separated list of the preferred pointing sources.
If true and running a 1mm track, the receivers will be tuned to 100 GHz for radio pointing.
If True, then attempt to observe one of the primary flux calibrators (a planet of MWC 349).
If True, then attempt to observe one of the secondary flux calibrators if a primary calibrator is not available OR you request to observe both primary and secondary calibrators. A more detailed description can be found in the FAQ page.
If True, then attempt to observe both primary and secondary flux calibrators. A more detailed description can be found in the FAQ page.
Total integration time in minutes on the flux calibrator source.
List of preferred primary flux calibrators in priority order.
List of preferred secondary flux calibrators in priority order.
Indicate which primary flux calibrators would be acceptable for your program.Last updated: June 28, 2010 by John Carpenter