[daip] [!5480]: aips - CVEL AIPS 2

[Carolina Rodriguez]

Carolina Rodriguez updated #5480
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              Status: Open (was: Closed)

CVEL AIPS 2
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           Ticket ID: 5480
                 URL: https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/5480
           Full Name: Carolina Rodriguez
               Email: ca.rodriguez at crya.unam.mx
             Creator: User
          Department: AIPS Data Processing
       Staff (Owner): Eric Greisen
                Type: Issue
              Status: Open
            Priority: Default
      Template Group: Default
             Created: 11 September 2014 04:45 PM
             Updated: 12 September 2014 04:46 PM



Don't worry about the SPLIT print out!! I made a mistake I copied the wrong log I'm sure I did follow the steps correctly.

I'm still missing something to understand CVEL. For example:

I'm looking for maser emission in a source whose LSR velocity is -17 km/s.
The observations were planned for August 29. The IF was centered on (channel 64 of a total of 128) the methanol maser emission (rest frequency=44069.430 MHz). In a ideal case, if the observations had been made that day in the exact
hour of the planning I find the line in the channel 64 because to this corresponds the sky frequency related to the rest frequency and the velocity mentioned above.

The case was not the ideal and the observations were made 2 days later, so the line is not longer in channel 64 because the observed frequency (equal to sky frequency) is diferrent than August 26. The rest frequency, the velocity of the source, the range of sky frequencies all of it had not been changed. The channel 64 is still having the sky frequency related to August 29 that's why the line is no longer here because it was observed in August 26, so it corresponds to another sky frequency.

Am I correct?

and so what? Why I have to apply CVEL? Everything is measure with respect to that day and that channel, what is the problem?

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