This model provides the spectra in the X-ray range (0.05-10 keV) emitted from a hydrogen atmosphere of a neutron star. There are three options : nonmagnetized (B < 10^{8} - 10^{9} G) with a uniform surface (effective) temperature in the range of ; a field B = 10^{12} G with a uniform surface (effective) temperature in the range of ; a field B = 10^{13} G with a uniform surface (effective) temperature in the range of . The atmosphere is in radiative and hydrostatic equilibrium; sources of heat are well below the atmosphere. The Comptonization effects (significant at) are taken into account. The model spectra are provided as seen by a distant observer, with allowance for the GR effects. The user is advised to keep M_{ns} and R_{ns} fixed and fit the temperature and the normalization. MagField must be fixed at one of 0, 10^{12}, or 10^{13}.
The values of the effective temperature and radius as measured by a distant observer (``values at infinity'') are :
where
is the gravitational redshift parameter.
Please send your comments/questions to Slava Zavlin (VYACHESLAV.ZAVLIN@msfc.nasa.gov) and/or George Pavlov (pavlov@astro.psu.edu). If you publish results obtained using these models, please reference Zavlin, V.E., Pavlov, G.G., & Shibanov, Yu.A. 1996, A&A, 315, 141 for nonmagnetic models, and Pavlov, G.G., Shibanov, Yu.A., Zavlin, V.E., & Meyer, R.D. 1995, in “The Lives of the Neutron Stars,” ed. M.A. Alpar, U. Kiziloglu, & J. van Paradijs (NATO ASI Ser. C, 450; Dordrecht: Kluwer), p. 71 for magnetic models.
par1 |
logT_{eff}, (unredshifted) effective temperature |
par2 |
M_{ns}, neutron star gravitational mass (in units of solar mass) |
par3 |
R_{ns}, neutron star radius (in km) |
par4 |
neutron star magnetic field strength (0, 1e12, or 1e13 G) |
K |
1/D^{2}, where D is the distance of the object in pc. |