Instructions for GBT12A-114: Constraining Stellar and Galactic Chemical Evolution with 3-Helium Abundances (Bania, Balser, & Rood)

Observing (X-band)

  1. Set the scan number to 1.
  2. Note the current LST.
  3. Run the scheduling block that matches the LST hour. There are 24 scheduling blocks: LST_0hr, LST_1hr, LST_2hr, ..., LST_22hr, LST23hr. Run the scheduling block that matches the LST hour. For example if the LST time is 12:05:00, 12:25:00, 12:35:00, 12:45:00, etc. then run the scheduling block called LST_12hr. That is, do not round up to the nearest hour.
  4. Repeat steps 2-3. If the scheduling block finishes before the end of the scheduled time then just start another one based on the LST time. In some cases the same source will be observed again. If the scheduled time ends before the scheduling block finishes then just abort (preferably after an OffOn pair has completed).
  5. If this project is run as a backup please notify Tom Bania (PI) and Dana Balser by email. We do not need to be contacted for approval. The email is only to inform us that our project has been run.

Quality Control

Each scheduling block consists of a peak/focus on a calibrator, and then total power position switching (OffOn) on a target source with the Spectrometer. Most scheduling blocks will run for 2 hours (1 peak/focus plus 8 OffOn pairs). There are a few scheduling blocks that will run for only 1 hour (1 peak/focus plus 4 OffOn pairs).

  1. Check the pointing/focus results. If the pointing is bad then just abort and re-run the scheduling block.
  2. Check the Spectrometer bandpass. We are tunned to 8 spectral windows at 2 polarizations. Make sure we have a reasonable bandpass in all spectra. For example, below is a screen shot of Astrid for our last run. All but one bandpass near 8900 MHz looks "normal"; that is, there is gain over the approximately 50 MHz bandwidth. Sometimes, as in the example below, there is only a problem with one bandpass. When this happens keep observing but please report the problem in your log and we will investigate. We do have some redundancy in our Spectrometer configuration so such data will still be useful.


-- DanaBalser - 2012-02-28
Topic revision: r1 - 2012-02-28, DanaBalser
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