中文摘要：

近来的观测表明，在射电宁静孤立中子星1E1207．4—5209的X-射线连续谱中存在几条等间隔的吸收线，能量分别为0．7、1．4和2．1keV．根据近年发展的四极近似下的量子回旋辐射理论，澄清了目前的一些疑问，肯定了它们是电子回旋吸收线，而不是质子回旋线．并从理论上确定了该中子星自转轴的空间取向．

英文摘要：

Recent observations of the radio-quite isolated neutron star 1E1207.4-5209 show several absorption lines with equal frequency-interval in the X-ray thermal continuum.The centroid energies of lines are at 0.7, 1.4, 2.1 keV, respectively. Using our improved formulae of quantum cyclotron radiation under the quadrupole approximation, we attemp to clarify the understanding of the absorption lines, which are still at issue. We confirm that they are the electronic cyclotron lines, rather than the proton-cyclotron. Besides, we determine the space orientation of the spin axis of neutron star.