zsmdust: extinction by dust grains in starburst galaxies
Extinction by dust grains suited to starburst galaxies and the hosts of
gamma ray bursts. The model can be applied over the IR, optical and UV
energy bands, including the full energy ranges of the Swift UVOT and
XMM-Newton OM detectors. The transmission is set to unity shortward of
912 Angstroms in the rest frame of the dust. This is incorrect physically
but does allow the model to be used in combination with an X-ray photoelectric
absorption model such as phabs. The extinction curve contains no
spectral features and is characterized by a powerlaw slope over spectral
wavelength. This model has been justified by e.g. Savaglio & Fall (2004)
because the apparent low metallicities within GRB hosts result in
no significant spectral features within the extinction curve, unlike those
found in local galaxies. The extinction at V, A(V) = E(B-V) x Rv. Standard
values for Rv are Milky Way = 3.08, LMC = 3.16 and SMC = 2.93 (from table
2 of Pei (1992), although these may not be applicable to
more distant dusty sources.
par1 |
E(B-V): color excess |
par2 |
ExtIndex: spectral index of the extinction curve |
par3 |
Rv: ratio of total to selective extinction |
par4 |
z: redshift |
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Last modified: Friday, 23-Aug-2024 13:20:40 EDT
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