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arXiv 1407.0914astro-ph.GAastro-ph.CO
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三个星系的故事:IRASF10398 +1455、IRASF21013-0739和SDSSJ0808 +3948的异常尘埃性质

A Tale of Three Galaxies: Anomalous Dust Properties in IRASF10398+1455, IRASF21013-0739 and SDSSJ0808+3948

Yanxia Xie, Lei Hao, Aigen Li

摘要:

在星系尺度上,9.7um硅酸盐辐射通常只出现在第一类活动星系核中。它们通常在~5- 8 μ m处显示平坦的发射连续谱,并且不存在多环芳烃(PAH)发射带。相比之下,星暴星系、亮红外星系(LIRGs)和超亮红外星系(ULIRGs)则呈现出5- 8 μ m的红色发射连续谱、10 μ m和18 μ m的强硅酸盐吸收特征和强PAH发射带。本文报道了利用Spitzer/红外光谱仪对IRASF 10398 +1455、IRASF 21013 -0739和SDSSJ 0808 +3948三个星系尘埃异常性质的探测结果。这些异常性质的特征是同时探测到5- 8 μ m的红色发射连续谱、9.7和18 μ m的硅酸盐发射特征以及强PAH发射带。这些显然是矛盾的尘埃红外发射特性进行了讨论,铁贫硅酸盐组合物,碳尘埃赤字,小晶粒尺寸和低尘埃温度在年轻的活动星系核阶段的这三个星系。

英文摘要:

On a galactic scale the 9.7um silicate emission is usually only seen in type 1 active galactic nuclei (AGNs). They usually also display a flat emission continuum at ~5--8um and the absence of polycyclic aromatic hydrocarbon (PAH) emission bands. In contrast, starburst galaxies, luminous infrared (IR) galaxies (LIRGs), and ultraluminous IR galaxies (ULIRGs) exhibit a red 5--8um emission continuum, strong 10um and 18um silicate absorption features, and strong PAH emission bands. Here we report the detection of anomalous dust properties by Spitzer/Infrared Spectrograph in three galaxies (IRASF10398+1455, IRASF21013-0739 and SDSSJ0808+3948) which are characterized by the simultaneous detection of a red 5--8um emission continuum, the 9.7 and 18um silicate emission features as well as strong PAH emission bands. These apparently contradictory dust IR emission properties are discussed in terms of iron-poor silicate composition, carbon dust deficit, small grain size and low dust temperature in the young AGN phase of these three galaxies.

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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