“SFR”的版本间差异

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==star formation law==
==star formation law==
* volumetric star formation law
* volumetric star formation law
: namely <mathρSFR∝ρα</math>gas with α≈2, is valid for both these regimes. This result indicates that the VSF law, which holds unbroken for a wide range of gas (≈3 dex) and SFR (≈6 dex) volume densities, is the empirical relation with the smallest intrinsic scatter and is likely more fundamental than surface-based star formation laws. [https://arxiv.org/abs/2010.07948]
: namely <math>$\rou_\propto SFR^\alpha </math>gas with α≈2, is valid for both these regimes. This result indicates that the VSF law, which holds unbroken for a wide range of gas (≈3 dex) and SFR (≈6 dex) volume densities, is the empirical relation with the smallest intrinsic scatter and is likely more fundamental than surface-based star formation laws. [https://arxiv.org/abs/2010.07948]





2020年10月19日 (一) 07:40的版本

指针

  • Halpha
Halpha的等值宽度10A对应的SSFR大概是3\time10^11年(Casade 2015)
  • [OII]3727
[OII]能够trace SFR,但是不是特别好,与金属丰度有关可以修正
在窄线AGN中,[OII]也能trace SFR,因为相对于[OIII]来说,[OII]主要由HII区共享,因此可以通过[OIII]来修正窄线区对[OII]的贡献,具体参见arXiv:1907.07933
  • [NeII]12.81u,[NeIII]15.55u,[NeV]14.32u
以上组合可以估算窄线AGN中的SFR,(Zhuang et al. 2019, ApJ, 873,103),因为[NeV]14.32u主要由AGN激发。
  • radio luminosity
[1] 1.4GHz的射电光度和总SFR线性相关,而且与金属丰度无关。单个波段的红外光度与射电光度(SFR)的关系和金属丰度有关
  • [CII]光度 [2]
高红移星系可以用CII光度来指针SFR,但是观测上偏弱,原因可能因为是高红移星系金属丰度低,以及分子氢(更有效的CII辐射)的比例低。
  • 跟中性氢的关系,冷的氢成份(T~10K),不是所有的
21cm 吸收线 arXiv:1901.06019

star formation law

  • volumetric star formation law
namely 解析失败 (未知函数“\rou”): {\displaystyle $\rou_\propto SFR^\alpha } gas with α≈2, is valid for both these regimes. This result indicates that the VSF law, which holds unbroken for a wide range of gas (≈3 dex) and SFR (≈6 dex) volume densities, is the empirical relation with the smallest intrinsic scatter and is likely more fundamental than surface-based star formation laws. [3]


尘埃的改正

  • 假设大质量恒星的电离光子加热了尘埃,从而用这些尘埃的MIR的辐射来改正,这个方法是否universal?
  • 1901/11321 对M31的研究表明,这个改正可能与星系的倾角有关(大倾角的时候,MIR的辐射来自路径上的,而不是HII区辐射的);还有星系的外围,尘埃的分布可能不是集中在HII周围。(盘星系外面,气体/尘埃的标高变大,而HII区的标高更小。)