The Misdirected Central Engine of the Hyperluminous Infrared Galaxy and Type 2 QSO IRAS P09104+4109
The Misdirected Central Engine of the Hyperluminous Infrared Galaxy and Type 2 QSO IRAS P09104+4109
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超光度红外星系的误导中央引擎和 2 型 QSO IRAS P09104 4109
DOI：
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发表时间：
1999
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通讯作者：
L. G. Sowinski
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作者：
D. Hines;G. Schmidt;B. Wills;Paul S. Smith;L. G. Sowinski
哈勃空间望远镜广角行星照相机2对超亮红外星系（和错误定向的类星体）IRAS P09104+4109的成像偏振测量显示了一个高度偏振（p <20%）的巨大（~5 kpc）双极反射星云，以核为中心。这一点，再加上我们以前探测到的广泛的，偏振的Mg II和新探测到的广泛的，偏振的巴耳末发射线在我们的地面分光偏振仪，证实了星云的叶主要是由散射光从错误的类星体和对象将无法区分典型的发光类星体，如果从任何一个极点。与先前发表的[O III] λλ4959、5007和[O II] λ3727的窄谱线图像相比，星云的北方叶与电离锥重合，因此撞击在散射物质上的同一束光也电离了窄谱线气体。双锥结构和高偏振表明，中心紫外连续光源被半开角约23°的尘埃环面包围，相对于我们的视线倾斜约37°。这个无线电中间物体的无线电结构也表明，它与中心电源有着长寿命的轴对称性，但与散射双锥有着不同的轴。我们认为，这种轴的差异背叛了一个灾难性的事件，改变了中央引擎的基本方向的历史-双锥定义了系统的当前轴。放射出无线电的等离子体正开始沿着这条新轴线向外移动，使旧的无线电波瓣失去能量。IRAS P09104+4109是第一个具有类星体光度和隐藏宽线的射电宁静/中间天体，它直接证明了在许多塞弗特核中存在的轴对称环面也存在于高光度天体中。
Hubble Space Telescope Wide-Field Planetary Camera 2 imaging polarimetry of the hyperluminous infrared galaxy (and misdirected QSO) IRAS P09104+4109 reveals a highly polarized (p≈20%) giant (~5 kpc) bipolar reflection nebula centered on the nucleus. This, together with our previous detection of broad, polarized Mg II and newly detected broad, polarized Balmer emission lines in our ground-based spectropolarimetry, confirms that the lobes of the nebula are dominated by scattered light from the misdirected QSO and that the object would be indistinguishable from typical luminous QSOs if viewed from either pole. Comparison with previously published narrowband images in the light of [O III] λλ4959, 5007 and [O II] λ3727 shows that the northern lobe of the nebula is coincident with the ionization cone, thus the same light that impinges on the scattering material also ionizes the narrow-line gas. The biconical structure and high polarization suggest that the central UV continuum source is surrounded by a dusty torus of half-opening angle ~23° inclined ~37° with respect to our line of sight. The radio structure of this radio-intermediate object also indicates a long-lived axisymmetry to the central power source, but with a different axis relative to the scattering bicone. We propose that this difference in axes betrays the history of a cataclysmic event that altered the fundamental orientation of the central engine—the bicone defines the current axis of the system. Radio-emitting plasma is beginning to move outward along this new axis, depriving the old radio lobes of power. IRAS P09104+4109 is the first radio-quiet/intermediate object of QSO luminosity and hidden broad lines to show direct evidence that the axisymmetric torus inferred to exist in many Seyfert nuclei is also present in objects of high luminosity.