Note: This program is normally called from the GUI front-end program grism-plot, which provides a graphical interface to set variables.

plot-grism plots spectra from FITS images taken with the Gemini’s in-line grism spectometer (filter T).  It assumes that the target star has been accurately centered. Small position tweaks can be made using option -t, which tweaks the strip spectrum vertical centering and the wavelength calibration. The program also optionally plots a reference spectrum from the KPNO library of stellar spectra ( Jacoby et  al. 1984 ApJSuppl ) if the star can be found in that catalog. 

Version: 3.30, 21 Jul 2017

Known bugs/issues: None

plot-grism -h

Program plot-grism plots grism spectra


  --version             show program's version number and exit

  -h, --help            show this help message and exit

  -b begin wavelength   Beginning plot wavelength [nm]

  -e end wavelength     End plot wavelength [nm]

  -B                    Plot Balmer lines

  -c Cal table          Calibration table (CSV file)

  -x Coeffs table       Coefficients table (CSV file)

  -H Hanning smoothing  Hanning smoothing window width [nm]

  -t tweak pointing     Tweak star position (0,0) [pixels]

  -T Plot title         Plot title [default: object coords date Z etc

  -o Output plot file   Ouput plot name [defaults to object_date]

  -p Plot format        Plot format: 0=PNG, 1=PDF (default 1)

  -P Plot options       Plot enhancements: 1: strip image, 2: 2x2

  -L                    Large font option (def. false)

  -r Ref. spectrum      Reference spectrum file (plotted with P=2)

  -v                    Verbose output

  -w Spectrum width     Spectrum width,pixels [15]

  -y y-axis min, max    Plot y-axis min,max, default: 0,1.2

  -z redshift           Redshift

  -C                    Plot carbon lines

  -N                    Plot nitrogen lines

  -O                    Plot oxygen lines

  -E                    Plot helium lines

Sample output plots (top: -P 2, bottom: -P 1)

© Robert Mutel 2018