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arXiv 1101.4941astro-ph.CO
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OH巨脉泽宿主星系的中红外特性。I:Spitzer IRS低分辨率和高分辨率光谱

Mid-infrared properties of OH megamaser host galaxies. I: Spitzer IRS low- and high-resolution spectroscopy

Kyle W. Willett, Jeremy Darling, Henrik W. W. Spoon, Vassilis Charmandaris, Lee Armus

摘要:

本文给出了51个OH超脉泽(OHMs)的中红外光谱和来自斯皮策太空望远镜红外光谱仪的测光结果,以及15个已证实没有超脉泽发射的星系的中红外光谱。大多数星系显示中等至深的9.7微米无定形硅酸盐吸收,与欧姆星系显示出更强的平均吸收和陡峭的20-30微米连续辐射比非masing星系。多环芳烃(PAHs)的排放,特别是在6.2,7.7和11.3微米,几乎在所有的系统中检测到。在90%以上的样品中观察到精细结构原子发射(包括[Ne II]、[Ne III]、[S III]和[S IV])和多个H2转动跃迁。一个星系的子集显示出来自稀有原子线的辐射,如[Ne V],[O IV]和[Fe II]。50%的OHM显示来自水冰和氢化无定形碳颗粒(HACs)的吸收,而来自CO2、HCN、C2 H2和结晶硅酸盐的吸收特征也在几种OHM中看到。来自34.6 μ m OH吸收的OH柱密度与来自非激射星系中1667 MHz OH吸收的OH柱密度相似,表明两种样品的激射分子丰度相似。这份数据文件提供了每个星系的完整中红外光谱,以及线通量和等效宽度,吸收特征深度和光谱指数的测量。

英文摘要:

We present mid-infrared spectra and photometry from the Infrared Spectrograph on the Spitzer Space Telescope for 51 OH megamasers (OHMs), along with 15 galaxies confirmed to have no megamaser emission above L_OH = 10^2.3 L_sun. The majority of galaxies display moderate-to-deep 9.7 um amorphous silicate absorption, with OHM galaxies showing stronger average absorption and steeper 20-30 um continuum emission than non-masing galaxies. Emission from multiple polycyclic aromatic hydrocarbons (PAHs), especially at 6.2, 7.7, and 11.3 um, is detected in almost all systems. Fine-structure atomic emission (including [Ne II], [Ne III], [S III], and [S IV]) and multiple H2 rotational transitions are observed in more than 90% of the sample. A subset of galaxies show emission from rarer atomic lines, such as [Ne V], [O IV], and [Fe II]. 50% of the OHMs show absorption from water ice and hydrogenated amorphous carbon grains (HACs), while absorption features from CO2, HCN, C2H2, and crystalline silicates are also seen in several OHMs. Column densities of OH derived from 34.6 um OH absorption are similar to those derived from 1667 MHz OH absorption in non-masing galaxies, indicating that the abundance of masing molecules is similar for both samples. This data paper presents full mid-infrared spectra for each galaxy, along with measurements of line fluxes and equivalent widths, absorption feature depths, and spectral indices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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