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COMPOSITE OF OBSERVED SPECTRUM OF GAMMA CRUCIS
Assembled 03-13-96

 gam Cru photometry file: photometry actually used to construct the spectrum

 Name    FWHM    Mag.+/-Unc.  Eff Wvl   Eff Wvl   Flambda     Source
                              (Vega)    (star)    W/cm2/um
          (um)                 (um)      (um)
 M       0.5418 -3.08  0.03    4.748    4.749    3.61E-15 Thomas et al. 1973
 N       5.1318 -3.38  0.02   10.161   10.250    2.17E-16 Thomas et al. 1973
 11.2    2.0209 -3.45  0.02   11.144   11.146    1.77E-15 Thomas et al. 1973
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 Photometry from Thomas et al. (1973, MNRAS, 165, 201) was used after applying
 zero point corrections based on their observed and our predicted magnitudes
 for Sirius (using our absolutely calibrated Sirius from Paper I).  Dr. H.
 Hyland kindly provided otherwise unavailable passbands from Thomas et al.
 (1973).


 Spectral fragments and portions of these actually used in observed spectrum
 (``used" may include combination with other data where overlaps occur)

 Fragment    Reference    Total range     Start and stop  Average resolving
                             (um)        wavelengths (um)      power
 KAO-NIR        1         3.95- 5.36        3.95- 5.20		 60
 KAO            2         5.22- 8.08        5.22- 8.08 		 60
 LRS            3         7.67-22.74        8.23-17.50  	 30
 LONG           4        16.27-35.02       16.27-35.02  	 30:
 VLONG          5        10.00-35.00       20.30-35.00  	 --

 References:
 1. FOGS data from KAO flight of April 11, 1988 [gamma Cru/alpha Hya].
 2. FOGS data from KAO flights of April 21, 1987 and April 11, 1988 in New
    Zealand [gamma Cru/alpha Hya].
 3. LRS raw data extracted from the old Groningen ``LRSVAX" database
    maintained at NASA-Ames, and recalibrated correctly.
 4. Glaccum (1990) data from KAO flights of April 17, 186 and November 19,
    1987, with calibration traceable to Mars (with 24 channel Goddard He-3
    bolometer spectrometer).
 5. Engelke Fn. used for T=3626K (Judge & Stencel 1991, ApJ, 371, 357).  Their
    estimated angular diameter of 41.1 mas was used as an intial value but
    we rescaled this to 26.06 mas.  This Engelke Function was locked to the
    photometrically scaled combination of 8-13 and LONG KAO spectra by splicing
    and used to replace the observations beyond 20.30 um.  We applied an
    estimated uncertainty in EFn. of 3.0%, allowing for the change in shape of
    the EFn. for a temperature uncertainty of 100K at this effective
    temperature.


 INFORMATION ON SPLICES AND BIASES INCURRED
 Process                   Factor determined        Bias (%)
 KAO-NIR cf. photometry        0.994                 3.11
 LRS blue/red bias               --                  0.05
 LRS cf. photometry            1.084                 1.33
 KAO joint splice to
  NIR and LRS                  0.994                 1.52
 LONG splice to LRS            0.970                 0.61
 Engelke Fn. splice to
  combined LRS and LONG        0.405                 1.38
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 Notes:
 1. Composite spectra are NOT tabulated at equal intervals of the wavelength,
    but rather at the wavelengths of the original model.
 2. In most cases "total uncertainty" is the error term most appropriate to
    use. It is the standard deviation of the spectral irradiance and includes
    the local and global biases.  Local and global biases are given as a
    percent of the irradiance.  The global bias does not contribute error to
    flux ratios or color measurements, and may, in those cases, be removed (in
    the RSS sense) from the total error.
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