ISO spectroscopy of star formation and active nuclei in the luminous infrared galaxy NGC 6240
ISO spectroscopy of star formation and active nuclei in the luminous infrared galaxy NGC 6240
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DOI：
10.1051/0004-6361:20031165
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发表时间：
2003-07
影响因子：
6.5
通讯作者：
D. Lutz;E. Sturm;R. Genzel;H. Spoon;A. Moorwood;H. Netzer;A. Sternberg
中科院分区：
文献类型：
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作者：
D. Lutz;E. Sturm;R. Genzel;H. Spoon;A. Moorwood;H. Netzer;A. Sternberg
我们介绍了合并星系NGC 6240的红外空间天文台中红外和远红外光谱，NGC 6240在（超）亮红外星系中恒星形成和AGN活动的许多方面都具有重要意义。中红外光谱显示出低激发精细结构线发射形式的星爆信号和芳香族“多环芳烃”特征。观察到一个强的高激发（O IV）线，它很可能起源于一个光学模糊的AGN的窄线区域。NGC 6240在分子氢的纯旋转谱线中显示出极强的辐射。我们认为，这种发射主要是由于其湍流中心气体成分和星爆超风的冲击。红外发射谱线的总激波冷却占测热光度的0.6%，主要通过旋转H2发射和（O I） 63m谱线进行。我们分析了几种估算NGC 6240星暴和AGN的光度的方法，并提出其辐射光度的贡献最有可能在50-75%星暴和25-50% AGN的范围内。
We present Infrared Space Observatory mid- and far-infrared spectroscopy of the merging galaxy NGC 6240, an object presenting many aspects of importance for the role of star formation and AGN activity in (ultra)luminous infrared galaxies. The mid-infrared spectrum shows starburst indicators in the form of low excitation fine-structure line emission and aromatic "PAH" features. A strong high excitation (O IV) line is observed which most likely originates in the Narrow Line Region of an optically obscured AGN. NGC 6240 shows extremely powerful emission in the pure rotational lines of molecular hydrogen. We argue that this emission is mainly due to shocks in its turbulent central gas component and its starburst superwind. The total shock cooling in infrared emission lines accounts for0.6% of the bolometric luminosity, mainly through rotational H2 emission and the (O I) 63m line. We analyse several ways of estimating the luminosities of the starburst and the AGN in NGC 6240 and suggest that the contributions to its bolometric luminosity are most likely in the range 50-75% starburst and 25-50% AGN.