Equation of state and opacities for hydrogen atmospheres of magnetars

The equation of state and radiative opacities of partially ionized, strongly magnetized hydrogen plasmas, presented in a previous paper for the magnetic field strengths, 8 x 10(11) Gless than or similar toBless than or similar to3 x 10(13) G, are extended to the field strengths, 3 x 10(13) Gless than or similar toB less than or equal to 10(15) G, relevant for magnetars. The first- and second-order thermodynamic functions and radiative opacities are calculated and tabulated for 5 x 10(5) K less than or equal to T less than or equal to 4 x 10(7) K in a wide range of densities. We show that bound-free transitions give an important contribution to the opacities in the considered range of B in the outer neutron star atmosphere layers. Unlike the case of weaker fields, bound-bound transitions are unimportant.