Pavlov2005 强磁场中的一价氦原子

计算了强磁场中的一价氦原子的能级。

这篇文章至少说明结合天文背景的原子能谱计算还有大量可以做的工作。

The Astrophysical Journal, 635:L61–L64, 2005 December 10

ONCE-IONIZED HELIUM IN SUPERSTRONG MAGNETIC FIELDS
George G. Pavlov1 and Victor G. Bezchastnov2,3
Received 2005 April 15; accepted 2005 November 1; published 2005 November 30
ABSTRACT
It is generally believed that magnetic fields of some neutron stars, the so-called magnetars, are enormously strong,
up to 1014–1015 G. Recent investigations have shown that the atmospheres of magnetars are possibly composed of
helium. We calculate the structure and bound-bound radiative transitions of the He
ion in superstrong fields,
including the effects caused by the coupling of the ion’s internal degrees of freedom to its center-of-mass motion.
We show that He
in superstrong magnetic fields can produce spectral lines with energies of up to ≈3 keV, and it
may be responsible for absorption features detected recently in the soft X-ray spectra of several radio-quiet isolated
neutron stars. Quantization of the ion’s motion across a magnetic field results in a fine structure of spectral lines,
with a typical spacing of tens of electron volts in magnetar-scale fields. It also gives rise to ion cyclotron transitions,
whose energies and oscillator strengths depend on the state of the bound ion. The bound-ion cyclotron lines of He

can be observed in the UV-optical range at G, and they get into the soft X-ray B
1013 range at B  1014 G.
Subject headings: atomic processes—line: formation—stars: individual (1E 1207.45209)—
stars: magnetic fields—stars: neutron—X-rays: stars