Goodman High Throughput Spectrograph

Updated Sep 19, 2017 (César Briceño)

NEW (Aug 15, 2017): Long slits have been renamed and reorganized, Please see the Goodman Long Slit page.

The Goodman High Throughput Spectrograph (GTHS) was built in the Goodman Laboratory at the University of North Carolina under the leadership of Prof. J. Christopher Clemens. It is an imaging spectrograph, capable of producing excellent image quality across a 7.2 arcmin diameter FOV (with a 0.15 arcsec/pixel scale), and spectra at various resolutions from the atmospheric UV cutoff all the way out to 850nm. It employs all transmissive optics, and Volume Phase Holographic (VPH) Gratings to achieve the highest possible throughput for low resolution spectroscopy over the 320-850 nm wavelength range. The paper describing the instrument is Clemens et al. (2004)

Quick facts:

  • Scale: 0.15 arcsec/pixel
  • Wavelength range: 320 - 900 nm
  • Two Cameras (detectors) are available (with various binning and region-of-interest options):
    • Blue Camera: optimized for the UV, down to 320nm
    • Red Camera: best response redward of ~400nm with negligible fringing
      • Which Camera: Blue or Red?
      • The Blue Camera is recommended for programs requiring the highest possible throughput blueward of ~4500 A, down to the atmospheric UV cutoff. Also, programs attempting fast time-series photometry should use the Blue Camera, since at present it has more flexible choice of Regions of Interest (ROI).
      • For all other programs, the Red Camera provides roughly equal response as the Blue Camera around ~4500 A and is better at redder wavelengths, with almost no fringing out to 9500 A.
  • Imaging: circular 7.2 arcmin diameter field. 
    • SDSS, Bessell and Narrow-band filters (4x4 inch square). Up to 4 filters for imaging
  • Spectroscopy: single slit and Multi-Object Slit (MOS)
  • MOS mode: masks span 3x5 arcmin rectangular field
  • Atmospheric Dispersion Corrector (ADC) available. The SOAR ADC is capable of full correction down to elevations of 30 deg above the horizon. Below that, and down to the 15 deg elevation limit of the telescope, the correction will be only partial; however, we recommend avoinding targets at elevations lower than 20 deg.  The ADC is most useful for MOS observations, or when the program does not allow orienting the slit at the paralactic angle.

General Information:

Observing Information and Tutorials:

Calibration Information:

Software for Goodman:

Observer Tools

Data Reduction Guides:  coming soon!