- NAME
PLANCK()
- PURPOSE
To calculate the Planck function in units of ergs/cm2/s/A
- CALLING SEQUENCE
bbflux = PLANCK( wave, temp)
- INPUT PARAMETERS
WAVE Scalar or vector giving the wavelength(s) in **Angstroms**
at which the Planck function is to be evaluated.
TEMP Scalar giving the temperature of the planck function in degree K
- OUTPUT PARAMETERS
BBFLUX - Scalar or vector giving the blackbody flux (i.e. !pi*Intensity)
in erg/cm^2/s/A in at the specified wavelength points.
- EXAMPLES
To calculate the blackbody flux at 30,000 K every 100 Angstroms between
2000A and 2900 A
IDL> wave = 2000 + findgen(10)*100
IDL> bbflux = planck(wave,30000)
If a star with a blackbody spectrum has a radius R, and distance,d, then
the flux at Earth in erg/cm^2/s/A will be bbflux*R^2/d^2
- PROCEDURE
The wavelength data are converted to cm, and the Planck function
is calculated for each wavelength point. See Allen (1973), Astrophysical
Quantities, section 44 for more information.
- NOTES
See the procedure planck_radiance.pro in
ftp://origin.ssec.wisc.edu/pub/paulv/idl/Radiance/planck_radiance.pro
for computation of Planck radiance given wavenumber in cm-1 or
wavelength in microns
- MODIFICATION HISTORY
Adapted from the IUE RDAF August, 1989
Converted to IDL V5.0 W. Landsman September 1997
Improve precision of constants W. Landsman January 2002