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CLASSY Data Products and File Extensions

 

  1. Co-added spectra (_co-added.fits)

CLASSY Spectra are stored as multi-extension fits (MEF) files. The current CLASSY files have 21 extensions (or less, depending on gratings included)): one primary header and 15 extensions of data tables. Spectral data tables are included for three dataset types:
  1. G130M: This is the highest resolution dataset, consisting of co-added G130M grating spectra only, with a resolution* of 0.060 Å/resel (6 pixels) or 14.77 km s-1/resel at LyA λ1215.
  2. HR: This is the high resolution dataset, consisting of co-added G130M+G160M grating spectra, with a resolution* of 0.073 Å/resel (6 pixels) or 14.20 km s-1/resel at CIV λ1550.
  3. MR: This is the moderate resolution dataset, consisting of co-added G130M+G160M+G185M grating spectra, with a resolution* of 0.222 Å/resel or 34.89 km s-1/resel at CIII] λ1909.
  4. LR: Some of the CLASSY targets also have low resolution (LR) G140L spectra, so a fourth LR dataset will be added in the future, with a resolution* of 0.498 Å/resel or 78.3 km s-1/resel at CIII] λ1909.

*The spectral resolutions here are the maximum resolutions for a point source, where actual spectral resolution of an individual galaxy will be less than this depending on the nature of the source profile. Resel here indicates a binning of six native pixels. 

 

Each of the three datasets has the following five data tables and extensions
  1. OBS DATASET CO-ADDED 
    • If multiple datasets exist, they are co-added.

  2. OBS DATASET CO-ADDED + GAL CORR

    • Ext 1 spectrum, plus corrected for galactic extinction.

  3. REST DATASET CO-ADDED + GAL CORR + zCORR

    • Ext 2 spectrum, plus redshift corrected.

  4. OBS DATASET CO-ADDED + GAL CORR + BINNED

    • Ext 2 spectrum, plus binned by N pixels, where N is given in the primary header.

  5. REST DATASET CO-ADDED + GAL CORR + BINNED + zCORR

    • Ext 3 spectrum, plus binned by N pixels, where N is given in the primary header.

Each data table has four columns:
  1. WAVE in units of Angstroms
  2. FLUX in units of ×10−15 erg cm−2 s−1 AA−1
  3. ERROR in units of ×10−15 erg cm−2 s−1 AA−1
  4. SNR