FIRE – Updates

FIRE – Updates

Here we correct some erroneous information in the current manual

FIRE noise pattern:

Resuming operations after the uncontrolled warm up of FIRE in the March 2020 due to the compressor failure a light noise pattern has been noticed on the detector. This pattern does not seem to affect data reduction or the overall instrument efficiency, provided all standard calibration files are properly obtained and used.

Time keyword on headers:

Currently the header keyword ACQTIME1 is the one that most accurately reports the starting UT time of a single exposure. 

It has been noted that there is a discrepancy between the keywords UT-TIME and ACQTIME1. When a loop is executed, the ACQTIME1 is updating correctly while the UT-TIME keyword remains the same for all images obtained during the loop. 
To correctly update the UT-TIME keyword, the following formula could be used: 

  • UT-TIME correct  = UT-TIME header + exposure time + readout time  (for single frames)
  • UT-TIME correct on loop N = UT-TIME of + (ACQTIME1_loop(N) – ACQTIME1_loop(1) )    (for loops)

Readout times differ according to the readmode – refer to the manual for more details. 

Acquisition Camera:

The correct pixel scale for the acquisition camera is 0.147″/pixel 

Slit size: 

The correct length of the echelle slit is 6 arcseconds  and for the long slit is 40 arcseconds with the exception of the 12″ slit that is 56″ long. 

Software access: 

The fire software can currently be accessed also from the Llama work station 

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