Reduction of spectrophomotometric standar star observation: Trouble with gqecorr

Home Forums Gemini Data Reduction Reduction of spectrophomotometric standar star observation: Trouble with gqecorr

This topic contains 2 replies, has 2 voices, and was last updated by  Nahir 11 months, 3 weeks ago.

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  • #1359

    Nahir
    Participant

    Hi all,

    I’m a a new Gemini trying to reduce GMOS-N standard star spectrum. When I run gqecorr, I have the next trouble:

    gmos> gqecorr gsN20130602S0263 refimages=gsN20130602S0268 fl_keep+

    GQECORR – Started: 2016-09-11T01:01:35

    GQECORR ERROR – GMOS + e2v DD CCD42-90: no coefficients found. Exiting

    GQECORR – Finished: 2016-09-11T01:01:50
    GQECORR – Exit status: ERROR

    I would appreciate any help, thanks

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    #1361

    jturner
    Keymaster

    Hi Nahir,

    This is because the QE variations of the GMOS-N e2v DD CCDs have never been calibrated (as mentioned in the details of the help page), so the step is not applicable for your data.

    Although the differences betweeen these chips are not known conclusively, the previous instrument scientist made this comment in response to a similar query last year:

    To my knowledge there is no need to apply the QE correction to these devices because they all originated from the same batch and have very similar QE as a function of wavelength.

    I would be very interested to know if you find evidence that measuring such values for these CCDs would be helpful. But as far as I know the QE values are all similar enough that there would be no value to applying the correction.

    I hope that clarifies things a bit.

    Cheers,

    James.

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    #1397

    Nahir
    Participant

    Thank you very much for your reply James, now everything is clear to me.

    Regards,

    Nahir

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