基于SDSS Blazar多波段辐射性质研究
文献类型：学位论文
| 作者 | 陈昭宇 |
| 学位类别 | 博士 |
| 答辩日期 | 2009-06-09 |
| 授予单位 | 中国科学院上海天文台 |
| 授予地点 | 上海天文台 |
| 导师 | 顾敏峰 |
| 关键词 | 活动星系核|类星体|BL Lacs|喷流|发射线|FSRQ|黑洞质量|伽玛射线 |
| 其他题名 | Multi-band emission in blazars based on SDSS data |
| 中文摘要 | In this thesis, we construct the spectral energy distribution (SED) for 185 SDSS DR3 flat-spectrum radio quasars (FSRQs), using multi-band data (i.e. ra-dio, IR, optical, UV, and X-ray). The relationships among the black hole mass, broad/narrow line region luminosity, synchrotron peak frequency/luminosity, Eddington ratio etc., are investigated. Moreover, we explore the Mbh-sigma relation for FSRQs, as well as the black hole activity fundamental plane. In addition, the SDSS photometry and spectroscopy data for bright AGNs detected by Fermi Gamma Ray Space Telescope are collected and reduced. The introduction is given in the first chapter, which mainly consists of the brief description on the AGNs subsets, the emission lines in AGNs, the central supermassive black hole in AGNs, and various multi-band surveys. In chapter 2, we constructed a sample of 185 Flat Spectrum Radio Quasars (FSRQs) by cross-correlating the Shen et al.'s SDSS DR3 X-ray quasar sample with FIRST and GB6 radio catalogues. From the spectrum energy distribution (SED) constructed using multi-band (radio, UV, optical, Infrared and X-ray) data, we derived the synchrotron peak frequency and peak luminosity. The black hole mass MBH and the broad line region (BLR) luminosity (then the bolometric luminosity) were obtained by measuring the line-width and strength of broad emission lines from SDSS spectra. We define a subsample of 118 FSRQs, of which the nonthermal jet emission is thought to be dominated over the thermal emission from accretion disk and host galaxy. For this subsample, we found 25 FSRQs having synchrotron peak frequency higher than the typical value for FSRQs. These sources with high peak frequency could be the targets for the Fermi Gamma-ray telescope. Only a weak anti-correlation is found between the synchrotron peak frequency and peak luminosity, while no strong correlation is present either between the synchrotron peak frequency and black hole mass, or between the synchrotron peak frequency and the Eddington ratio L_bol/L_Edd. When combining the FSRQs subsample with theWu et al.'s sample of 170 BL Lac objects, the strong anti-correlation between the synchrotron peak frequency and luminosity apparently presents covering about seven order of magnitude in nu_peak. However, the anti-correlation differs with the blazar sequence in the large scatter. At similar peak frequency, the peak luminosity of FSRQs with nu_peak > 1015 Hz is systematically higher than that of BL Lac objects, with some FSRQs out of the range covered by BL Lac objects. Although high nu_peak are found in some FSRQs, they do not reach the extreme value of BL Lacs. For the subsample of 118 FSRQs, we found significant correlations between the peak luminosity and black hole mass, the Eddington ratio, and the BLR luminosity, indicating that the jet physics may be tightly related with the accretion process. For 81 FSRQs with measured [O III] line width, the relationship between the black hole mass and velocity dispersion indicated with [O III] line width is investigated. We found the Mbh-sigma_[OIII] relation is deviated from Tremaine et al. relation for nearby inactive galaxies, with a larger black hole mass at given velocity dispersion. There is no strong evidence of cosmology evolution in Mbh - sigma_[OIII] relation up to z ~ 0:8. A significant correlation between the [O III] luminosity and Broad Line Region (BLR) luminosity is found. When transferring the [O III] luminosity to Narrow Line Region (NLR) luminosity, the BLR luminosity is, on average, larger than NLR one by about one order of magnitude. We found a strong correlation between the synchrotron peak luminosity and NLR luminosity, which implies a tight relation between the jet physics and accretion process. In chapter 3, we collected all available spectra and photometric data from SDSS catalogue for bright AGNs complied from the first three months of the Fermi large area telescope all-sky survey. Based on the 106 high-confidence and 10 low-confidence association bright AGN list, the photometry data are collected from SDSS DR7 for 28 sources (12 BL Lacs and 16 FSRQs), two of which are low-confidence association bright AGNs. Among these 28 SDSS photometric sources, SDSS spectra are available for 20 sources (6 BL Lacs and 14 FSRQs). The black hole mass MBH and the broad line region (BLR) luminosity were obtained for 14 FSRQs by measuring the line-width and strength of broad emission lines from SDSS spectra. The broad emission lines measurements of five FSRQs are presented for the first time in this work. The optical continuum emission of these 14 FSRQs is found to be likely dominated by the nonthermal jet emission through comparing the relationship between the broad Mg II line and continuum luminosity to that of radio quiet AGNs. The black hole mass of 14 FSRQs ranges from 10^{8.2} M_sun to 10^{9.9} M_sun, with most of sources larger than 10^9 Msun. The Eddington ratio L_bol/L_Edd ranges from 10^{-1.5} to ~ 1. This implies that the optically thin, geometrically thick accretion disk may exist in these FSRQs. In last chapter, the brief outlook is given. |
| 英文摘要 | 本文主要利用多波段(射电，红外，光学，紫外，X射线) 数据，构建SDSS第三期中的平谱射电类星体(FSRQs) 的能谱分布，并研究这些源中央的黑洞质量、宽线区光度，窄线区光度，同步辐射峰值光度、频率，爱丁顿比率等参量之间的相互关系，并对平谱射电类星体的MBH - sigma关系，以及黑洞活动基本面进行了研究。另外，对Fermi gamma 射线空间望远镜观测到的亮AGN 源在SDSS 源表中的光谱及测光数据进行分析研究。 本文第一章首先介绍相关研究背景。活动星系核的分类，重点介绍与本文相关的Blazar 天体性质，然后介绍AGN 的发射线性质，与AGN 中央的黑洞。由于本文涉及到多波段的数据处理，本章最后介绍多波段巡天数据。 第二章介绍我们利用多波段的数据（包括射电，红外，光学，紫外，X射线）交叉认证，得到185个平谱射电类星体(FSRQs)，对利用这些多波段数据构建的能谱分布进行拟合得到同步辐射的峰值频率与峰值光度。通过测量宽发射线的宽度与强度，结合已有的经验公式估算出中央黑洞质量、宽发射线区光度、热光度等。通过估算吸积盘和寄主星系的热辐射，185个FSRQs 中的118个源为非热辐射主导源。 在这118个源中，我们发现有25个源的同步辐射峰值频率大于FSRQs 的典型值。这118个源的同步辐射峰值频率与峰值光度之间只有比较弱的反相关，并且峰值频率与黑洞质量、爱丁顿比率之间也没有强的相关性。但我们发现同步辐射的峰值光度与黑洞质量、宽线区光度、爱丁顿比例之间有很强的相关性。并合170个BL Lac 源后，同步辐射峰值频率与峰值光度之间有很强的反相关，但与Blazar序列有所不同，弥散很大。 在185个FSRQs中，81 个源有[O III] 5007ºA测量，我们使用[O III]的线宽来指代恒星速度弥散，发现MBH - sigma 关系偏离Tremaine et al. 关系，在给定¾处，黑洞质量更大。没有明显证据表明MBH - sigma 在z < 0:8 内有演化。由[O III]光度估计窄线区光度后，发现宽线区光度平均地比窄线区光度大一个量级左右，统计意义上热光度可以由Lbol = 2025 L[O III] 来估算，另外，同步辐射峰值光度与窄线区光度之间有强相关，说明喷流与吸积过程有密切联系。 第三章介绍费米大面积望远镜最初三个月的全空间巡天(The Fermi large area telescope all-sky survey)的亮AGNs 在SDSS 源表中的光谱及测光的数据。基于106个高置信度与10个低置信度的亮AGN 表，测光数据从SDSS DR7 中得到28个源(12个BL Lacs 与16 个FSRQs)，其中2个是低置信度的亮AGNs 。在这28 个SDSS 测光源中有20个源有光谱数据(6个BL Lacs 与14 个FSRQs )，通过测量FSRQs 光谱中宽发射线的宽度与强度，得到其黑洞质量，宽线区光度。其中有5个FSRQs 的宽发射线在这里是首次测量。通过对比这类射电AGNs 的MgII 线与连续谱光度之间的关系，发现14个源的光学连续谱辐射可能是喷流的非热辐射所主导。 最后第四章作了一个简单的展望。 |
| 语种 | 中文 |
| 公开日期 | 2011-07-01 |
| 页码 | 111 |
| 源URL | [http://119.78.226.72//handle/331011/14734]  |
| 专题 | 上海天文台_中国科学院上海天文台学位论文 |
| 推荐引用方式 GB/T 7714 | 陈昭宇. 基于SDSS Blazar多波段辐射性质研究[D]. 上海天文台. 中国科学院上海天文台. 2009. |
入库方式： OAI收割
来源：上海天文台
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。