“星系中的常见发射线”的版本间差异

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:*[NII]205mu, N原子的电离势是14.5ev，比H要高，因此[NII]线是在HII区才有
:*[NII]205mu, N原子的电离势是14.5ev，比H要高，因此[NII]线是在HII区才有
::*weak [NII] 205 um: 恒星形成 [http://arxiv.org/abs/1607.02520]
::*weak [NII] 205 um: 恒星形成 [http://arxiv.org/abs/1607.02520]
::* with an ionization potential of 14.53eV, it traces the bulk of the warm ionized medium
::*1)withanionizationpotentialof 14.53eV, it tracesthebulkof thewarmionizedmedium;2) in combinationwithotherfinestructurelinessuchas[CII]158µm, [NII]122µm, itenablesconstraintsonkeyphysicalproperties, suchasthefractionofthe[CII]158µmarisingfromtheionized medium,metalenrichment,andelectrondensity(e.g.,Cunninghametal. 2020;Dohertyetal. 2020;Tadakietal. 2022);3) Itcanbeusedasanindicatorforstarformationrates(SFR)as bothcomputationmodels (Orsi et al. 2014)andobservations (Farrahetal. 2013;Zhaoetal. 2013,2016)haveshownalinearcorrelationbetweenthe[NII]205µmline luminosityand SFRinlocal star-formingandultraluminous infraredgalaxies (ULIRGs), andagoodcorrelationwiththestar formationrate surfacedensity(Herrera-Camusetal. 2016) (from 2502.08984)
::* in combination with other fine structure lines such as [CII]158µm, [NII]122µm, it enables constraints on key physical properties, such as the fraction of the [CII]158µm arising from the ionized medium, metal enrichment, and electron density (e.g., Cunningham et al. 2020;Dohertyetal. 2020;Tadakietal. 2022)
::* It can be used as an indicator for SFR as both computation models (Orsi et al. 2014) and observations (Farrah et al. 2013;Zhaoetal. 2013,2016) have shown a linear correlation between the [NII]205µm line luminosity and SFR in local star-forming and ultra luminous infrared galaxies (ULIRGs)


==coronal lines ==
==coronal lines ==

2025年2月14日 (五) 08:37的最新版本

参见SFR

电离势

  • H0 13.6
  • He0 24.6
  • S++ 34.8, O+ 35.1
  • He+ 54.4, O++ 54.9
  • O0可以电离到3种不同的O+状态（4S,2D,2P）,从O0（3P）到O+的电离势为13.62

光学波段

  • [OII] doublet (3737A)
  • [OIII] (4959A and 5007A)
  • Balmer series (6563A, 4861A, 4340A, 4103A, ...).
  • [NII]6583A
  • 发射线的线比可以区分不同的电离机制，金属丰度 BPT diagram,详细的工作可参见[1]
  • [NII]/[OII]: . intermediate mass stars are the main source of nitrogen en- richment in massive galaxies (Moll´a et al. 2015), the gas from their stellar winds should be, on average, extremely nitrogen- rich.
  • SII：电离势 10.4ev

红外谱线

  • 精细结构线 [2]
  • 最强的线 [CII]158mu [OIII]88mu [OI]64mu，[OIII]来自HII区
  • The new [OIV]25.9μm/[OIII]88μm vs [NeIII]15.6μm/[NeII]12.8μm diagram is proposed as the best diagnostic to separate: i) AGN activity from any kind of star formation; and ii) low-metallicity dwarf galaxies from starburst galaxies.
  • the ([NeIII]15.6μm + [NeII]12.8μm)/([SIV]10.5μm + [SIII]18.7μm) ratio is proposed as a promising metallicity tracer to be used in obscured objects, where optical lines fail to accurately measure the metallicity.
  • [CII] 158$\mu$m fine-structure line，trace regions of active star formation and is the main coolant of the cold, neutral atomic medium.[3]
  • C原子的电离势11.2eV，因此C+在中性和电离去都存在，因此[CII]158mu能不能做SFR的指针有争议 (arXiv1910.0541),[CII]是PDR区域最有效的冷却线
  • both [CI] and CO emission trace gas that is predominantly molecular, with a density n ~ 500-1000 cm−3, [CII] traces lower density material (n ~ 100 cm−3) [4]
  • [NII]205mu, N原子的电离势是14.5ev，比H要高，因此[NII]线是在HII区才有
  • weak [NII] 205 um: 恒星形成 [5]
  • with an ionization potential of 14.53eV, it traces the bulk of the warm ionized medium
  • in combination with other fine structure lines such as [CII]158µm, [NII]122µm, it enables constraints on key physical properties, such as the fraction of the [CII]158µm arising from the ionized medium, metal enrichment, and electron density (e.g., Cunningham et al. 2020;Dohertyetal. 2020;Tadakietal. 2022)
  • It can be used as an indicator for SFR as both computation models (Orsi et al. 2014) and observations (Farrah et al. 2013;Zhaoetal. 2013,2016) have shown a linear correlation between the [NII]205µm line luminosity and SFR in local star-forming and ultra luminous infrared galaxies (ULIRGs)

coronal lines

  • Higher-ionization, collisionally excited optical forbid�den lines, known as optical “coronal lines” (CLs; first discovered in the solar corona)
为什么在AGN中很弱?因为尘埃的沉降效应使得它们很弱[6]

理论模型

  • arXiv:2501.05424 从HII的模拟出发，考虑各种因素（如HII区物理层参数的分布，DIG的共享，分子云的Av等）来mock星系的发射线
取自“http://202.127.29.3/~shen/wiki/index.php?title=星系中的常见发射线&oldid=4192”