论文标题
$^7 $是Nova V5668 SGR中的丰富性
$^7$Be abundance in nova V5668 Sgr doesn't contradict theory
论文作者
论文摘要
$^7 $ BE的共振线目前在五个Novae中检测到。与热核闪光灯的模型预测相比，从$^7 $ be，ii和ca \，II线的同等宽度估计的这种同位素的可用丰度要高得多。为了查明这种差异的原因，我们通过计算两区模型框架中热核燃烧的动力学来探索较高$^7 $的可能性，并且发现即使是有利的参数选择$^7 $，也不会超过$ 3 \ cdot10^\ cdot10^{-5} $。这与已知的理论结果一致，并在理论和观察结果之间留下了差异。我们发现，矛盾是由以下假设引起的：be，ii/be的电离分数等于ca \，ii/ca的电离分数，以前是为了估计$^7 $是丰富的。在Nova V5668 SGR的情况下，由于电离电位的差异，与Ca \，II/CA相比，Be，II/Be的电离级数至少高出$ \ sim 10 $。我们对Nova V5668 SGR的$^7 $的新估计不矛盾。根据{\ em积分}的观察值，从$^7 $衰减中计算出的478 kev gamma-quanta的通量与上限一致。
Resonance lines of $^7$Be are detected currently in five novae. Available abundances for this isotope estimated from equivalent widths of $^7$Be\,II and Ca\,II lines are significantly higher compared to predictions of models for the thermonuclear flash. In attempt to pinpoint the reason for this disparity we explore the possibility for the higher $^7$Be yield via computing kinetics of the thermonuclear burning in the framework of two-zone model and find that even for a favorable choice of parameters $^7$Be mass fraction does not exceed $3\cdot10^{-5}$. This is consistent with known theoretical results and leaves the disparity between the theory and observations unresoved. We find that the contradiction is caused by the assumption that the ionization fraction of Be\,II/Be is equal to that of Ca\,II/Ca, which has been adopted formerly in order to estimate the $^7$Be abundance. In the case of nova V5668 Sgr the ionization fraction of Be\,II/Be turns out to be at least by a factor of $\sim 10$ higher compared to Ca\,II/Ca due to the difference of ionization potentials. Our new estimate of the $^7$Be mass fraction for nova V5668 Sgr does not contradict the theory. The calculated flux of 478 keV gamma-quanta from the $^7$Be decay is consistent with the upper limit according to {\em INTEGRAL} observations.
