Improved collision strengths and line ratios for forbidden [O III] far-infrared and optical lines
Improved collision strengths and line ratios for forbidden [O III] far-infrared and optical lines
复制标题
提高了禁止 [O III] 远红外和光学线的碰撞强度和线比
DOI：
10.1111/j.1745-3933.2012.01252.x
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
W. Eissner
中科院分区：
文献类型：
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作者：
E. Palay;S. Nahar;A. Pradhan;W. Eissner
远红外线和光学[O III]线是有用的温度-密度诊断星云以及尘埃遮蔽的天体物理源。基态能级1s^22s^22p^3 \ ^3P_{0，1，2}之间的精细结构跃迁产生了52和88微米谱线，而$^3P_{0，1，2}、，^1D_2、^1S_0$能级之间的跃迁产生了众所周知的光学谱线4363、4959和5007埃。这些线主要由电子碰撞激发激发。但是，尽管它们在星云诊断中的重要性，相关的精细结构跃迁的碰撞强度还没有计算充分考虑相对论效应。我们提出了Breit-Pauli R-矩阵计算的碰撞强度与高分辨率的共振结构。我们发现显着差异高达20%的麦克斯韦平均速率系数从以前的作品。我们还将这些列表，以将温度降低到100 K，从而能够确定在寒冷的尘埃环境中的物理条件，例如Herschel空间天文台观察到的光解离区域和超亮红外星系。我们还研究了改进的碰撞强度对温度和密度敏感线比的影响。
Far-infrared and optical [O III] lines are useful temeprature-density diagnostics of nebular as well as dust obscured astrophysical sources. Fine structure transitions among the ground state levels 1s^22s^22p^3 \ ^3P_{0,1,2} give rise to the 52 and 88 micron lines, whereas transitions among the $^3P_{0,1,2}, ,^1D_2, ^1S_0$ levels yield the well-known optical lines 4363, 4959 and 5007 Angstroms. These lines are excited primarily by electron impact excitation. But despite their importance in nebular diagnostics collision strengths for the associated fine structure transitions have not been computed taking full account of relativistic effects. We present Breit-Pauli R-matrix calculations for the collision strengths with highly resolved resonance structures. We find significant differences of up to 20% in the Maxwellian averaged rate coefficients from previous works. We also tabulate these to lower temperatures down to 100 K to enable determination of physical conditions in cold dusty environments such photo-dissociation regions and ultra-luminous infrared galaxies observed with the Herschel space observatory. We also examine the effect of improved collision strengths on temperature and density sensitive line ratios.