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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.

HEASoft and XSPEC are now available as conda packages. See details ....


NS Hydrogen Atmosphere model with electron conduction and self-irradiation

This model is now in the Xspec release and this page is superceded by the Xspec manual

This model interpolates from a grid of NS atmosphere calculations provided by George Rybicki and Ramesh Narayan to output a NS atmosphere spectrum. The model grids cover a wide range of surface gravity and effective temperature, and incorporate thermal electron conduction and self-irradiation by photons from the compact object. This code assumes negligible (less than 10^9 G) magnetic fields and a pure hydrogen atmosphere. A detailed description of the model is given in Heinke et al. (2006), ApJ in press, astro-ph/0506563 (see also McClintock et al. 2004, ApJ, 615, 402).

The model parameters are :

par1 = logTeff, (unredshifted) effective surface temperature
par2 = Mns, neutron star gravitational mass (in units of solar mass)
par3 = Rns, neutron star radius (in km)
par4 = dist, distance to the neutron star (in kpc)

The source code, lmodel.dat entries and model data file are available. The model data file should either be placed in the $XANADU/spectral/modelIonData directory (for v12), $XANADU/spectral/xspec/manager directory (for v11), or the environment variable NSATMOS_FILE set to the full pathname of the model data file (for v11 or v12).

The normalization should normally be fixed at one, which corresponds to emission from the entire surface of the neutron star.