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Chary & Elbaz (2001, ApJ 556, 562)  SEDs and computation of Lir(8-1000 microns) :


A library of 105 template spectral energy distributions (SEDs) was built in Chary & Elbaz (2001) to reproduce the observed luminosity-luminosity correlations for local galaxies. This library is contained in the file: chary_elbaz.save (IDL save file) and is shown below:

The chary_elbaz.xdr (IDL save file; under IDL do: restore, 'chary_elbaz.save',/verb) contains the following information:

N.B.: the optical-near IR part of the SEDs was arbitrarily defined since only the mid, far IR and sub-millimeter wavelength ranges were used to constrain the SEDs. It was defined in such a way to reproduce the observed Lir versus L(B) very sparse correlation.


Galaxies do present a dispersion around a median trend in the correlations used to define those SEDs. This dispersion defines a minimum uncertainty when trying to derive the total IR luminosity, and therefore star formation rate (SFR), of a distant galaxy (minimum since distant galaxies may exhibit differents SEDs than local ones). The following program computes the total IR luminosity, Lir(8-1000 um), of a galaxy as derived from its 24 um Spitzer-MIPS flux density only, assuming the Chary & Elbaz (2001) library of template SEDs.


In the case of a galaxy lying at a redshift of z=0.875, possessing a flux density of 250 microJy at 24um, under IDL, type:
print,chary_elbaz_24um(0.875 , 250.)

N.B.: the default cosmology used in the computation of the luminosity distance is:
H0=70, O_m=0.3, O_l=0.7
If you prefer to use another cosmology, e.g. H0=75, O_m=0.27, O_l=0.73 then type:
print,chary_elbaz_24um(0.875 , 250.,H0=75.,o_m=0.27,o_l=0.73)


For the ISOCAM filter LW3 (12-18um, centered at 14.3um):
print,chary_elbaz_15um(0.875 , 250.)


For a top-hat filter of any resolution and central wavelength:

here central wavelength= 350 um ( the default resolution is R= lambda/dlambda= 3)
print, chary_elbaz(0.875, 250.,350.resol=3.)


The codes are contained in the gzipped tar file : chary_elbaz_codes.tar.gz

You will also need to retrieve the following file containing the repsonse curves of the filters: responsivity.tar.gz