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To find and download HEASARC data in the cloud, you can use astroquery.heasarc or download our new tool, hark.

The HEASARC and NuSTAR teams are greatly saddened by the sudden passing of Katja Pottschmidt. Most recently Katja was the lead scientist for the NuSTAR Guest Observer Facility (GOF), a role she had supported for many years. During her science career she worked on many other high energy astrophysics missions and played an integral role in advancing our knowledge of the universe. She was a wonderful colleague and friend and will be keenly missed by all who knew her.

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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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Next: zbabs: EUV ISM attenuation Up: Multiplicative Model Components Previous: xion: reflected spectrum of   Contents