活动星系核统一模型与铁Kα发射线

发布时间：2018-01-26 08:37

本文关键词： 活动星系统一模型射线　出处：《中国科学技术大学》2010年博士论文　论文类型：学位论文

【摘要】： 活动星系核(AGN)统一模型认为Seyfert 1和Seyfert 2星系的中心引擎结构是相同的,他们之间所表现的不同类型主要是因为对观测者的视角不同。在Seyfert 2星系中没有发现宽的发射线是由于视线方向上几何和光学厚的尘埃环的遮蔽引起的。对Seyfert 2星系的偏振观测发现了隐藏的宽发射线是对统一模型最有力的支持。X射线可以用来测量Seyfert 2星系视线方向上尘埃环的吸收,因而也可以用来验证统一模型。X射线照射到黑洞周围的气体如吸积盘或尘埃环上还会产生显著的位于6.4 keV附近的铁Ka荧光线辐射,这种荧光线辐射被认为是探测活动星系核内区结构的重要探针。我们在第一章综述了统一模型和铁Kα荧光线研究现状。本文的工作正是围绕着统一模型和铁Kα荧光线的研究展开的,具体的结果如下：在第二章中,我们研究两类Seyfert 2星系(有无偏振的宽发射线)的核区遮蔽与统一模型的关系。我们选取了z0.06有偏振观测的Seyfert 2星系样本,其中29个Seyfert 2探测到了偏振的宽发射线,25个Seyfert 2没有发现偏振的宽线,并比较了两类Seyfert 2星系的X射线波段的吸收柱密度(NH),FX／F[OⅢ]比,和Fe Kα线等值宽度。这些观测量可以做为核区遮蔽的指示器。我们发现对于高光度的Seyfert 2星系(L[OⅢ]1041 erg S-1),有偏振宽线Seyfert 2的NH要明显的小于没有偏振宽线的Seyfert 2,置信水平为92.3%：大部分NH1023.8cm-2的Seyfert 2有偏振的宽发射线(86%),而大于这个吸收柱密度时,有偏振宽线的Seyfert 2比例为54%。当比较它们的FX／F[OⅢ]和Fe Kα线等值宽度时,区别的显著水平有所提高,分别为99.1%和95.3%。我们发现两类Seyfert 2星系核区遮蔽的区别不是由于观测的选择效引起的。我们的结果第一次在高显著水平上发现,除了核区活动性,尘埃环的遮蔽对探测偏振的宽线有很大的影响。我们的结果可以在统一模型的框架下得到解释,即尘埃环的倾角越大,X-ray吸收越强,对宽线散射屏的遮蔽也越严重。在第三章中,我们详细研究了Seyfert 2星系NGC 7590的核区遮蔽性质。NGC 7590的偏振观测没有发现隐藏的宽线区,而之前低分辨率的ASCA观测认为这个星系几乎没有X射线吸收(NH9×1020 cm-2),与统一模型的预言不一致。我们利用最新的XMM-Newton卫星对NGC 7590的观测,发现其X-ray辐射由核外的极亮X射线源(ULX)和延展的寄主星系的辐射主导。与寄主星系的辐射相比,核区辐射非常弱。利用XMM-Newton测量的核区2-10 keV流量,我们发现NGC 7590的FX／F[OⅢ]非常小(0.1),表明NGC 7590很可能是康普顿厚的。在第四章中,我们利用Chandra高能光栅(HEG)的观测,系统研究了36个低吸收(NH1023 cm-2)活动星系核的窄Fe Ka荧光发射线的特征。我们在33个AGN中探测到了Fe K线辐射,其线心能量分布集中在～6.4 keV,其中80%的测量位于6.38-6.43 keV。因此,我们证实了AGN中窄Fe Ka线是普遍存在的,它们应起源于非常冷的、中性或低电离的物质。此外,我们发现加权平均的Fe Kα线等值宽度(EW)为53±3 eV,其中70%测量的1σ上限100eV。对于有多次观测的源,我们发现在误差范围内,观测和观测之间没有明显的线流量光变。我们可以限制27个源的Fe Ka线宽度,加权平均的半高全宽FWHM=2060±230 km S-1。我们比较了12个源的Fe Kα线宽与光学HβFWHM的关系。结果发现FWHM(Fe K)／FWHM(Hβ)的分布较广,表明不同源的铁线发射区相对于宽线区的尺度不尽相同。最后,利用HEG测量的窄Fe Ka线参数,我们证实了EW和X-ray光度(Lx)的反相关关系(即X-ray Baldwin效应),以及EW和爱丁顿比(Lx／LEdd)的反相关关系。在第五章中,我们分析了XMM-Newton于2003年对Seyfert 1.9星系NGC2992的观测,发现其X射线流量处于迄今发现的最高态(为历史最低2-10keV流量的23.5倍左右),并且在～5-7 keV波段有显著的相对论性宽Fe Ka发射线特征。与低态的Suzaku数据相比,宽铁K线的流量随连续谱有相同幅度的光变,表明宽铁K线与连续谱流量正相关。这种行为与其它活动星系核观测到的宽铁K线流量不随连续谱变化正好相反。第六章是全文的总结和未来研究的展望。
[Abstract]:Active galactic nuclei (AGN) unified model that center engine structure of Seyfert 1 and Seyfert 2 galaxies are the same, different types of performance between them is mainly because of the different perspective of the observer. In the galaxy Seyfert 2 was not found in the broad emission lines along the line of sight is due to shadowing the geometrical and optical thickness of dust ring the polarization observations of NGC 2. Seyfert discovered the secret of the broad lines of the unified model is the most powerful support.X ray can be used to measure the Seyfert 2 galaxies along the line of sight ring dust absorption, which can also be used to verify gas around the United Model of.X rays into the black hole as the accretion disk or torus, Ka produced significant fluorescent iron line near 6.4 keV radiation, the fluorescent radiation is considered as an important probe of AGN within the district structure. In the first chapter, we review The present situation of the unified model and the iron K alpha fluorescence line is studied. The work of this paper is focused on the study of the unified model and the Fe K alpha fluorescence line, and the specific results are as follows:
In the second chapter, we study two classes of Seyfert 2 galaxies (with no polarization broad rays) the nuclear obscuration and unified model. We selected the z0.06 polarization observations of galaxy Seyfert 2 samples, of which 29 Seyfert 2 to detect the polarization of the broad lines, 25 Seyfert 2 not found wide line polarization, absorption column density and compare the two kinds of Seyfert X ray band 2 Galaxy (NH), the FX / F[O III] ratio, equivalent and Fe K a line width. These measurements can be an indicator for nuclear obscuration. We found that the high luminosity of the galaxy Seyfert 2 (L[O 3]1041 ERG S-1), a 2 NH wide line polarization Seyfert was significantly smaller than no polarization wide line Seyfert 2, 92.3% confidence level: most of the NH1023.8cm-2 Seyfert 2 polarization broad lines (86%), and greater than the absorption column density, polarization wide line Seyfert 2 when the ratio of 54%. The comparison of their FX / F[O III and Fe] K a line equivalent width, significant difference increased, respectively 99.1% and 95.3%. we found that two Seyfert 2 galaxies are covered difference is not due to selection effect caused by observation. Our results found for the first time in the high level, in addition to nuclear the activity of the region, has a great influence on the dust shield ring probe polarization wide line. Our results can be explained in the framework of the unified model, namely the angle of dust ring is bigger, stronger absorption of X-ray, covering wide line scattering screen is more serious.
In the third chapter, we studied the Seyfert 2 Galaxy NGC 7590 nuclear obscuration polarization observations 7590 properties of.NGC no hidden broad line region, and before the ASCA low resolution observations that the galaxy almost no X ray absorption (NH9 * 1020 cm-2), is not consistent with the predictions using the unified model. Our new XMM-Newton satellite observations of the 7590 NGC, it is found that the X-ray radiation from outside the nuclear ultraluminous X-ray source X (ULX) radiation of the host galaxy and the extension of the LED. Compared with the radiation of the host galaxy, nuclear radiation is very weak. Measured by XMM-Newton nuclear region 2-10 keV flow, we found that NGC 7590 FX / F[O III] is very small (0.1), showed that NGC 7590 is likely to be Compton thick.
In the fourth chapter, we use the Chandra grating (HEG) high energy observation system of 36 low absorption (NH1023 cm-2) AGN narrow Fe Ka fluorescence emission line features in the 33 AGN. We detected the Fe K line, the distribution line of heart energy concentrated in the keV to 6.4 the 80% measure is located in 6.38-6.43 keV. so we confirmed that the Fe Ka AGN in the narrow line is widespread, they should be originated in the very cold, neutral or low ionized materials. In addition, we found that the equivalent Fe K alpha weighted average line width (EW) of 53 + 3 eV, of which 70% were measured the 1 sigma limit 100eV. for multiple observations of the source, we found that in the range of error, between observations and no obvious change of light flow line. We can limit the 27 source Fe Ka line width, the weighted average of the full width half maximum FWHM=2060 + 230 km S-1. we compared the Fe K alpha linewidth and light 12 A source The relationship between H beta FWHM. The results showed the FWHM (Fe K) / FWHM (H 3) the wide distribution shows that different source iron line emission zone relative to the broad line region of different scales. Finally, using HEG Fe Ka measurement of narrow line parameters, we confirmed that EW and X-ray spectrophotometry (Lx) the inverse correlation (X-ray, Baldwin, EW and Eddington effect) and the ratio (Lx / LEdd) anti correlated.
In the fifth chapter, we analyze the observations of Seyfert XMM-Newton in 2003 1.9 Galaxy NGC2992, found the X ray flow in the highest state found so far (23.5 times the lowest flow rate of 2-10keV or so), and in the 5-7 ~ keV band has significant relativity of wide Fe Ka emission line features compared to Suzaku data. With the low state, wide iron K line flow with continuous spectrum has the same magnitude of the light, that broad iron K line and continuous spectrum is positively related to the flow rate. This kind of behavior and other activities broad iron K line flow galaxies observed with continuous spectrum changes on the contrary.
The sixth chapter is the summary of the full text and the prospect of the future research.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：P145.9

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