calz_unred: Deredden a galaxy spectrum using the Calzetti et al. (2000)...
In astrolibR: Astronomy Users Library

Description Usage Arguments Details Value Author(s) References See Also Examples

Deredden a galaxy spectrum using the Calzetti et al. (2000) recipe

1	calz_unred(wave,flux,ebv,R_V)

`wave`	wavelength in Angstroms, scalar or N-vector
`flux`	calibrated flux vector, scalar or N-vector
`ebv`	color excess E(B-V), scalar
`R_V`	ratio of total to selected extinction, defauly=4.05 (optional)

Calzetti et al. (2000) developed a recipe for dereddening the spectra of galaxies where massive stars dominate the radiation output, valid between 0.12 to 2.2 microns. Reddening values are extrapolated between 0.12 and 0.0912 microns. Calzetti et al. (2000) estimate R_V = 4.05 +/- 0.80 from optical-IR observations of four starburst galaxies.

If a negative E(B-V) is supplied, then fluxes will be reddened rather than deredenned. Note that the supplied color excess should be that derived for the stellar continuum, ebv(stars), which is related to the reddening derived from the gas, ebv(gas), via the Balmer decrement by ebv(stars) = 0.44*ebv(gas).

Output funred values will be zero outside the wavelength domain 0.0912 to 2.2 microns.

funred

unreddened flux, scalar or N-vector.

Written W. Landsman Raytheon ITSS December, 2000

R adaptation by Arnab Chakraborty June 2013

Calzetti, D., Armus, L., Bohlin, R. C., Kinney, A. L., Koorneef, J. & Storchi-Bergmann, T., The dust content and opacity of actively star-forming galaxies, Astrophysical Journal, 533, 682-695, 2000. http://adsabs.harvard.edu/abs/2000ApJ...533..682C

ccm_unred

1
2
3

w <- 1200 + seq(50, 2000, by=50)  # wavelength vector
f <- rep(1, length(w))   # flat initial spectrum
calz_unred(w, f, ebv=0.1)

 [1] 2.936915 2.842477 2.764148 2.697826 2.640592 2.590337 2.545512 2.504968
 [9] 2.467846 2.433492 2.401411 2.371220 2.342622 2.315387 2.289333 2.264316
[17] 2.240222 2.216959 2.194452 2.172640 2.151472 2.130906 2.110907 2.091445
[25] 2.072492 2.054025 2.036025 2.018473 2.001352 1.984647 1.968343 1.952429
[33] 1.936891 1.921719 1.906900 1.892424 1.878282 1.864464 1.850960 1.837761