测量中子星表面辐射谱的引力红移被认为是探究这类致密天体基本物理特性最为直接有效的手段. 但是,脉冲星、磁星这些强磁化中子星表面的辐射红移不仅源于引力的作用, 还需要考虑星体表面的磁化等离子体以及由超强磁场所诱导的量子电动力学(quantum electrodynamics, QED) 真空极化效应对辐射的电磁作用. 运用Gordon有效度规理论研究磁化等离子体以及QED真空极化效应对星体辐射的影响. 计算结果表明, 一般情况下对辐射引力红移的修正起主要作用的是星体表面的磁化等离子体, 但在某些特定情况下, 还必须考虑QED真空极化效应的作用.
Measuring the gravitational redshift of neutron star emission lines is the most effective and feasible method for determining fundamental properties of these compact objects. It is found that redshift of emission lines of pulsars and magnetars is produced not only by the gravitational field but also by surface magnetoplasma and quantum electrodynamics (QED) vacuum polarization effect induced by the super-strong magnetic field.The effect on the stellar emission caused by magnetoplasma and quantum vacuum polarization is studied within the framework of Gordon’s effective metric theory. It is shown that modification of gravitational redshift is mainly caused by magnetoplasma, and contributions of the QED vacuum polarization effect should also be
taken into account in some particular cases.
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