标题： 用斯皮策太空望远镜观测的经典活动星系核的中红外光谱 显示英文标题

标题： Mid-Infrared Spectra of Classical AGN Observed with the Spitzer Space Telescope

摘要： 使用斯皮策红外太空望远镜上的红外光谱仪（IRS）获得的波长范围从5微米到37微米之间的低分辨率（65 < R < 130）和高分辨率（R ~ 600）光谱被展示出来，这些光谱来自八种之前广泛研究过的经典活动星系核（AGN）。这些AGN的光谱作为比较标准，用于许多对象，包括首次用IRS在中红外波段观测的高红移源。 这些AGN包括NGC4151、Markarian 3、I Zwicky 1、NGC 1275、半人马座A、NGC 7469、Markarian 231和NGC 3079。这些源被用来展示在其他波段具有完全不同分类标准的对象所遇到的红外光谱范围，但毫无疑问都包含AGN。 总体光谱特征——包括连续谱形状、星云发射线、硅酸盐吸收和发射特征以及PAH发射特征——被考虑以了解基于中红外光谱的光谱分类如何与先前从光学光谱得出的分类相关联。这些AGN还与其他恒星爆发星系（如之前用IRS观测过的NGC 7714和紧凑型低金属含量恒星爆发SBS 0335-052）的相同参数进行了比较。 结果证实了AGN中PAH发射特征的强度要低得多，但在该样本中没有任何光谱参数能够仅根据连续谱斜率明确区分AGN和恒星爆发。 显示英文摘要

摘要： Full low resolution (65<R<130) and high resolution (R~600) spectra between 5 microns and 37 microns obtained with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope are presented for eight classical active galactic nuclei (AGN) which have been extensively studied previously. Spectra of these AGN are presented as comparison standards for the many objects, including sources at high redshift, which are being observed spectroscopically in the mid-infrared for the first time using the IRS. The AGN are NGC4151, Markarian 3, I Zwicky 1, NGC 1275, Centaurus A, NGC 7469, Markarian 231, and NGC 3079. These sources are used to demonstrate the range of infrared spectra encountered in objects which have widely different classification criteria at other wavelengths but which unquestionably contain AGN. Overall spectral characteristics - including continuum shape, nebular emission lines, silicate absorption and emission features, and PAH emission features - are considered to understand how spectral classifications based on mid-infrared spectra relate to those previously derived from optical spectra. The AGN are also compared to the same parameters for starburst galaxies such as NGC 7714 and the compact, low metallicity starburst SBS 0335-052 previously observed with the IRS. Results confirm the much lower strengths of PAH emission features in AGN, but there are no spectral parameters in this sample which unambiguously distinguish AGN and starbursts based only on the slopes of the continuous spectra.