“尘埃”的版本间差异

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*尘埃与气体有关,气体的光深可以从low-ionization interstellar (IS) absorption lines(e.g., Si II, O I, Fe II)获得 (Shapley et al. 2003)
*尘埃与气体有关,气体的光深可以从low-ionization interstellar (IS) absorption lines(e.g., Si II, O I, Fe II)获得 (Shapley et al. 2003)
:e.g. If the two Si II transitions at 1260 and 1527A are optically thin, then the ratio of their equivalent widths will be W1260/W1527 > 6. The observed ratio is W1260/W1527 ~ 1, implying that the lines are saturated and hence their depths are sensitive to the covering fraction of Si II-enriched material.
:e.g. If the two Si II transitions at 1260 and 1527A are optically thin, then the ratio of their equivalent widths will be W1260/W1527 > 6. The observed ratio is W1260/W1527 ~ 1, implying that the lines are saturated and hence their depths are sensitive to the covering fraction of Si II-enriched material.
*银河系盘外围区域的气尘比可能会偏大 [https://arxiv.org/abs/1708.05359]
: We find a weak trend of decreasing infrared to ~20 cm flux density ratios with increasing Rgal, in agreement with previous extragalactic results, possibly indicating a decreased dust abundance in the outer Galaxy.



:对于比912A更短的波长来说,气体的吸收消光是最主要的而不是dust,但是气体和尘埃是相关的,参见[http://arxiv.org/abs/1606.00434]
:对于比912A更短的波长来说,气体的吸收消光是最主要的而不是dust,但是气体和尘埃是相关的,参见[http://arxiv.org/abs/1606.00434]
*模型THEMIS The Heterogeneous dust Evolution Model for Interstellar Solids) [http://www.ias.u-psud.fr/themis/]
*模型THEMIS The Heterogeneous dust Evolution Model for Interstellar Solids) [http://www.ias.u-psud.fr/themis/]

2017年8月18日 (五) 08:25的版本

  • 发射线的消光可能和连续谱的消光不同
  • Halpha/Hbeta 线比
内禀数值:2.86(恒星形成),3.1(AGN) 参见Osterbrock & Ferland 2006
  • 尘埃在8000A左右有一个Extended Red Emission(ERE)的连续谱发射
  • 尘埃的红外发射: dustEM
  • 尘埃与气体有关,气体的光深可以从low-ionization interstellar (IS) absorption lines(e.g., Si II, O I, Fe II)获得 (Shapley et al. 2003)
e.g. If the two Si II transitions at 1260 and 1527A are optically thin, then the ratio of their equivalent widths will be W1260/W1527 > 6. The observed ratio is W1260/W1527 ~ 1, implying that the lines are saturated and hence their depths are sensitive to the covering fraction of Si II-enriched material.
  • 银河系盘外围区域的气尘比可能会偏大 [1]
We find a weak trend of decreasing infrared to ~20 cm flux density ratios with increasing Rgal, in agreement with previous extragalactic results, possibly indicating a decreased dust abundance in the outer Galaxy.


对于比912A更短的波长来说,气体的吸收消光是最主要的而不是dust,但是气体和尘埃是相关的,参见[2]
  • 模型THEMIS The Heterogeneous dust Evolution Model for Interstellar Solids) [3]

多波段

875个近距离星系 v<3000km/s
42 个波段 (UV - micro-wave)
孔径匹配 Comprehensive & Adaptable Aperture Photometry Routine (CAAPR)

消光曲线

  • 分子云中的turblence导致尘埃粒子按照颗粒大小分层分布,可以解释分子云中的消光曲线和其它地方不同[5]

盘星系的尘埃分布

可以延展到2R25,[6]:
密度轮廓比较follow恒星,而不是恒星形成(气体?)
有温度梯度,从中心25K到边缘15K
盘上的尘埃可以解释类星体的受到的intergalactic的红化现象?
多波段结果进行对比[7]