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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gabs, zgabs: gaussian absorption line

A gaussian absorption line as a multiplicative model. The zgabs variant includes redshift as a parameter.

$\displaystyle M(E) = exp(-d*g(E)) $
$\displaystyle g(E) = {2\over{\sigma\sqrt{2\pi}(1-\mathit{erf}(-E_l/(\sigma\sqrt{2})))}} \exp\left({-(E-E_l)^2\over{2\sigma^2}}\right) $
where:

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

For zgabs the corresponding formula is:

$\displaystyle M(E) = exp(-d*g(E)) $
$\displaystyle g(E) = {2\over{\sigma*\sqrt{2\pi}(1-\mathit{erf}(-E_l/(\sigma\sqrt{2})))}} \exp\left({-(E(1+z)-E_l)^2\over{2\sigma^2}}\right) $
where:

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