Equation of state and opacities for hydrogen atmospheres of strongly magnetized cooling neutron stars

Abstract

We study partially ionized hydrogen plasma at temperatures T = 10^{5.5}-10^{6.5} K and magnetic fields B = 10^{12}-10^{13} G, typical of photospheres of isolated neutron stars. We construct an analytic model of the plasma free energy and derive a generalized Saha equation which is used to obtain the opacities.

4 pages, 2 embedded figures, LaTeX using epsf.sty, neu.sty, and tron.sty (included). PostScript version also available at http://www.ioffe.rssi.ru/dtastrop.html Published in "Neutron Stars and Pulsars," eds. N. Shibazaki et al. (Universal Academy Press, Tokyo, 1998) p. 161