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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xscat: dust scattering

This model calculates the X-ray scattering cross section of a population of dust grains as a function of energy, given a specific dust grain position and an extraction region. As the grain position gets closer to the source of the X-rays for a constant extraction region, the cross section drops as more X-rays remain within the extraction circle. For constant dust grain position, the cross section decreases with increasing extraction region size because more photons remain within it.

A detailed description of the model can be found in Smith, Valencic & Corrales (2016).

The model parameters are as follows.

par1 = $NH$ interstellar hydrogen column density ($10^{22}$ cm$^{-2}$).
par2 = $Xpos$ the relative position of the dust along the line of sight. This varies between 0 for dust at the observer and 1 for dust at the source.
par3 = $Rext$ the radius of the circular extraction region (arcsec).
par4 = $DustModel$ the dust model used (see Smith et al. 2016). The model options are 1=MRN, 2=WD, and 3=ZDABAS.

The third and fourth parameters must be frozen.

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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.