Radiative transitions of the helium atom in highly magnetized neutron star atmospheres
Abstract
Recent observations of thermally emitting isolated neutron stars revealed spectral features that could be interpreted as radiative transitions of He in a magnetized neutron star atmosphere. We present Hartree-Fock calculations of the polarization-dependent photoionization cross-sections of the He atom in strong magnetic fields ranging from 1012 to 1014 G. Convenient fitting formulae for the cross-sections are given along with the related oscillator strengths for various bound-bound transitions. The effects of finite nucleus mass on the radiative absorption cross-sections are examined using perturbation theory.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2008
- DOI:
- 10.1111/j.1365-2966.2007.12518.x
- arXiv:
- arXiv:0704.1598
- Bibcode:
- 2008MNRAS.383..161M
- Keywords:
-
- atomic processes;
- magnetic fields;
- stars: atmospheres;
- stars: neutron;
- Astrophysics
- E-Print:
- 14 pages, 7 figures. Minor changes. MNRAS in press