Motivated by the measurement of redshifted Fe H$\alpha$ lines during type I X-ray bursts on EXO 0748-676 (Cottam, Paerels & Mendez), we study the formation of atomic Fe lines above the photosphere of a bursting neutron star ($k_BT_{\rm eff} \approx 1-2 {\rm keV}$). We discuss the effects of Stark broadening, resonant scattering and NLTE (level population) on the formation of hydrogenic Fe H$\alpha$, Ly$\alpha$ and P$\alpha$ lines. From the observed equivalent width of the Fe H$\alpha$ line, we find an implied Fe column of $1-3 \times 10^{20} {\rm cm}^{-2}$, which is 3-10 times larger than the Fe column calculated from the accretion/spallation model of Bildsten, Chang & Paerels. We also estimate that the implied Fe column is about a factor of 2-3 larger than a uniform solar metallicity atmosphere. We discuss the effects of rotational broadening and find that the rotation rate of \EXO must be slow, as confirmed by the recent measurement of a 45 Hz burst oscillation by Villarreal & Strohmayer. We also show that the Fe Ly$\alpha$ EW $\approx$ 15-20 eV (redshifted 11-15 eV) and the P$\alpha$ EW $\approx$ 4-7 eV (redshifted 3-5 eV) when the H$\alpha$ EW is 10 eV (redshifted 8 eV). The Ly$\alpha$ line is rotationally broadened to a depth of $\approx 10%$, making it difficult to observe with {\it Chandra}. We also show that radiative levitation can likely support the Fe column needed to explain the line.
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机译:用等离子体约束实现重力场的动态控制热核聚变(TLTS)方法,通过热辐射等离子体绝缘的壁反应堆防止中子辐射并节省磁场和等离子体的混合,使用旋转磁场的异步磁惯性约束反应堆(AMITYAR和HFM)为实施该方法,在该反应器中点燃热核反应的方法,爆炸式等离子发生器(VIP)的实施方法,以及具有HFM的特立普安瓿,以实现D + T反应和具有超高温热度的HFM D +3НЕ和1Н+11В的高温反应