HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.

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Next: wabs, zwabs: photoelectric absorption, Up: Multiplicative Model Components Previous: varabs, zvarabs: photoelectric absorption


vgabs, zvgabs: gaussian absorption line with sigma in km/s

A gaussian absorption line as a multiplicative model with sigma in km/s. The zvgabs variant includes redshift as a parameter.

$\displaystyle M(E) = exp\left(-\left(par3/(\sqrt{2\pi}(par2/c))\right) exp\left(-.5\left(\left(E-par1\right)/(par2/c)\right)^2\right)\right) $
where:

par1 line energy in keV.
par2 line width (sigma) in km/s.
par3 line depth in keV. The optical depth at line center is par3/(par2/c)/$\sqrt{2\pi}$.

For zvgabs the corresponding formula is:

$\displaystyle M(E) = exp\left(-\left(par3/(\sqrt{2\pi}(par2/c))\right) exp\left(-.5\left(\left(E(1+z)-par1\right)/(par2/c)\right)^2\right)\right) $
where:

par1 line energy in keV.
par2 line width (sigma) in km/s.
par3 line depth in keV. The optical depth at line center is par3/(par2/c)/$\sqrt{2\pi}$.
par4 $z$, redshift

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Last modified: Friday, 23-Aug-2024 13:20:40 EDT

HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.