超过10 keV的测量是对活动星系核(AGN)进行无偏普查的最佳资源之一。我们提出了60个月的观测结果的硬X射线天空与雨燕/BAT。在这段时间内,BAT在全天巡天中探测到(在15- 55千电子伏波段)720个源,其中428个与活动星系核有关,大部分都在附近。我们的样本具有可忽略不计的不完整性和统计的\sim 2倍以上类似完整的活动星系核。我们的样本包含(至少)15个真正的康普顿厚度AGN和3个可能的候选者。康普顿厚度的活动星系核代表了~5%的活动星系核样品检测到高于15千电子伏。我们使用BAT数据集,以完善的LogN-LogS的AGN这是非常重要的,现在NuSTAR准备发射,对评估AGN的贡献宇宙X射线背景的确定。我们表明,LogN-LogS的AGN选择以上10千电子伏,现在建立了~10%的精度。导出了康普顿厚度活动星系核的光度函数,并对去吸收光度大于2 $\times10^{42}$,erg s $^{-1}$的天体测得空间密度为7.9 $^{+4.1}_{-2.9}\times10^{-5}$,Mpc $^{-3}$.由于BAT活动星系核大多是局域的,它们使我们能够研究活动星系核在邻近宇宙中的空间分布,而不考虑吸收。我们发现AGN的浓度在空间上与当地(<85 Mpc)宇宙中最大的物质聚集相吻合。有一些证据表明,在这些密集区域的方向上,塞弗特2型天体的比例大于平均水平。
英文摘要:
Surveys above 10 keV represent one of the the best resources to provide an unbiased census of the population of Active Galactic Nuclei (AGN). We present the results of 60 months of observation of the hard X-ray sky with Swift/BAT. In this timeframe, BAT detected (in the 15--55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGN, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of \sim2 larger over similarly complete sets of AGN. Our sample contains (at least) 15 bona-fide Compton-thick AGN and 3 likely candidates. Compton-thick AGN represent a ~5% of AGN samples detected above 15 keV. We use the BAT dataset to refine the determination of the LogN--LogS of AGN which is extremely important, now that NuSTAR prepares for launch, towards assessing the AGN contribution to the cosmic X-ray background. We show that the LogN--LogS of AGN selected above 10 keV is now established to a ~10% precision. We derive the luminosity function of Compton-thick AGN and measure a space density of 7.9$^{+4.1}_{-2.9}\times10^{-5}$\,Mpc$^{-3}$ for objects with a de-absorbed luminosity larger than 2$\times10^{42}$\,erg s$^{-1}$. As the BAT AGN are all mostly local, they allow us to investigate the spatial distribution of AGN in the nearby Universe regardless of absorption. We find concentrations of AGN that coincide spatially with the largest congregations of matter in the local (<85 Mpc) Universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions.
Hard X-ray ($\geq 10$ keV) observations of Active Galactic Nuclei (AGN) can shed light on some of the most obscured episodes of accretion onto supermassive black holes. The 70-month Swift/BAT all-sky survey, which probes the 14-195 keV energy range, has currently detected 838 AGN. We report here on the broad-band X-ray (0.3-150 keV) characteristics of these AGN, obtained by combining XMM-Newton, Swift/XRT, ASCA, Chandra, and Suzaku observations in the soft X-ray band ($\leq 10$ keV) with 70-month averaged Swift/BAT data. The non-blazar AGN of our sample are almost equally divided into unobscur…
Suzaku View of the Swift/BAT Active Galactic Nuclei. III. Application of Numerical Torus Models to Two Nearly Compton Thick AGNs (NGC 612 and NGC 3081)
New AGN classifications in the Swift/BAT All-Sky Hard X-ray Survey
通过在San Pedro Martir(Mexico)望远镜上进行的光学活动,并使用6dF档案(http://www.aao.gov.au/local/www/6df,Jones et al. 2004),我们确定或给出了Swift/BAT 22个月全天硬X射线巡天(Baumgartner et al. 2008,Tueller et al. 2010)中8个新发现的活动星系核(AGN)的更好分类。所有这些物体都有用Swift/XRT或Chandra或XMM存档数据进行的观测,这些数据使我们能够精确地确定它们的光学对应物,这要归功于这些天文台提供的精确(优于几个角秒)软X射线位置。这些信息使我们能够获得所有这些对应物的光谱,因为只有三个光谱是在线可用的,但没有通量校准,使我们能够揭示它们的真实性质(Baumgartner等人,2008年仅根据它们的X射线性质进行了初步分类)。在这里,我们提出的光谱,以及相应的发现图表获得的DSS-II红色调查,这8个源。我们发现我们的样品是由7个Seyfert 2和1个Seyfert 1组成的,红移在0.009和0.068之间。
We study the observed relation between accretion rate (in terms of L/L_Edd) and shape of the hard X-ray spectral energy distribution (namely the photon index Gamma_X) for a large sample of 228 hard X-ray selected, low-redshift active galactic nuclei (AGN), drawn from the Swift/BAT AGN Spectroscopic Survey (BASS). This includes 30 AGN for which black hole mass (and therefore L/L_Edd) is measured directly through masers, spatially resolved gas or stellar dynamics, or reverberation mapping. The high quality and broad energy coverage of the data provided through BASS allow us to examine several al…
We present the combined Chandra and Swift-BAT spectral analysis of seven Seyfert 2 galaxies selected from the Swift-BAT 100-month catalog. We selected nearby (z<=0.03) sources lacking of a ROSAT counterpart and never previously observed with Chandra in the 0.3-10 keV energy range, and targeted these objects with 10 ks Chandra ACIS-S observations. The X-ray spectral fitting over the 0.3-150 keV energy range allows us to determine that all the objects are significantly obscured, having NH>=1E23 cm^(-2) at a >99% confidence level. Moreover, one to three sources are candidate Compton thick Active …
The bulk of the X-ray emission in Active Galactic Nuclei (AGN) is produced very close to the accreting supermassive black hole (SMBH), in a corona of hot electrons which up scatters optical and ultraviolet photons from the accretion flow. The cutoff energy ($E_{\rm C}$) of the primary X-ray continuum emission carries important information on the physical characteristics of the X-ray emitting plasma, but little is currently known about its potential relation with the properties of accreting SMBHs. Using the largest broad-band (0.3-150 keV) X-ray spectroscopic study available to date, we investi…