“Balmer decrement”的版本间差异
跳到导航
跳到搜索
（创建页面，内容为“*HII region: case B Balmer recombination decrement Ha/Hb = 2.85 for T = 10^4 K and Ne=10^4 cm-3 (Brocklehurst 1971). *In AGNs, however, the harder photoionizing sp...”） |
无编辑摘要 |
||
| 第1行： | 第1行： | ||
*HII region: case B Balmer recombination decrement Ha/Hb = 2.85 for T = 10^4 K and Ne=10^4 cm-3 |
*HII region: case B Balmer recombination decrement Ha/Hb = 2.85 for T = 10^4 K and Ne=10^4 cm-3 (Brocklehurst 1971). |
||
:Halpha: Hbeta: Hgamma = 2.8:1.0:0.47 for temperatures near 10^4 °K |
|||
(Brocklehurst 1971). |
|||
*In AGNs, however, the harder photoionizing spectrum results in a large transition zone, or partly ionized region, in which H° coexists with H |
*In AGNs, however, the harder photoionizing spectrum results in a large transition zone, or partly ionized region, in which H° coexists with H |
||
2018年8月2日 (四) 04:43的版本
- HII region: case B Balmer recombination decrement Ha/Hb = 2.85 for T = 10^4 K and Ne=10^4 cm-3 (Brocklehurst 1971).
- Halpha: Hbeta: Hgamma = 2.8:1.0:0.47 for temperatures near 10^4 °K
- In AGNs, however, the harder photoionizing spectrum results in a large transition zone, or partly ionized region, in which H° coexists with H
+ and free electrons. In this zone collisional excitation is also important in addition to recombination collisional excitation (Ferland and Netzer 1983; Halpem and Steiner 1983). The main effect of collisional excitation is to enhance Ha. The higher Balmer lines are less affected because of their larger excitation energies and smaller excitation cross sections.(Veilleux & Osterbrock (1987).
- Ha/Hb = 3.1 (Ferland and Netzer 1983, Péquignot 1984, Gaskell 1984; Gaskell and Ferland 1984).