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1.
之前的研究显示水超脉泽辐射更倾向位于被物质严重遮掩的活动星系核中,因此,作者选择了一个活动星系核样本,开展水超脉泽的搜寻工作.该样本主要基于它们的中红外辐射特性(谱和颜色特性)而被证认为活动星系核,并由于被严重遮掩而未能在之前的光学观测中被证认.作者申请并获准应用德国Effelsberg 100 m口径望远镜,于2014年1月开展了水超脉泽的搜寻工作.观测结果显示只有几个源的谱存在可能的脉泽辐射,根据观测结果的噪声水平和这些星系的距离,作者估算了每个源的水脉泽辐射光度的上限值,这将对以后更高灵敏度的搜寻工作提供指导.  相似文献   

2.
水超脉泽辐射光度很大,因此活动星系核被公认为是其唯一的能源,而近来[OIV]发射线被认为可以准确地示踪活动星系核各向同性的强度.为了分析活动星系核和脉泽辐射间的内在联系,对所有发表的水脉泽星系的(OIV]发射线观测资料进行了全面调研和收集.整个脉泽样本和3个恒星形成脉泽的[oIV]线的平均光度分别为10^7.09±0....  相似文献   

3.
水超脉泽辐射光度很大,因此活动星系核被公认为是其唯一的能源,而近来[OIV]发射线被认为可以准确地示踪活动星系核各向同性的强度.为了分析活动星系核和脉泽辐射间的内在联系,对所有发表的水脉泽星系的(OIV]发射线观测资料进行了全面调研和收集.整个脉泽样本和3个恒星形成脉泽的[oIV]线的平均光度分别为10^7.09±0.17和10^-6.55太阳光度.对比脉泽星系和非脉泽星系样本的[OIV]光度,没有发现大的差别.对于同活动星系核成协的脉泽星系,发现它们的[OIV]光度和水脉泽光度间存在一个明显的相关,尽管存在较大的弥散.如果活动星系核是脉泽辐射的能量激发源,那么这一相关性为[OIV]发射线可以很好示踪活动星系核强度的观点提供了支持.  相似文献   

4.
截至目前,在已搜寻过的5 000多个星系中,只在180多个星系中探测到水脉泽辐射,这种脉泽的绝大多数与活动星系核(AGN)辐射相关.文章利用先进的红外卫星Spitzer对水脉泽星系样本多个波段的观测资料(3.6μm、4.5μm、5.8μm、8.0μm和24.0μm),计算得到该样本的红外辐射光度、谱指数等物理参量.通过统计对比分析水脉泽寄主星系和非水脉泽寄主星系在各个波段的辐射光度和谱指数、中红外能谱分布,结果显示:①水脉泽星系有较大的中红外光度,尤其在长波24μm波段更为明显;②水脉泽和非水脉泽星系的谱指数与能谱分布没有明显区别;③水脉泽光度与其寄主星系的中红外光度统计显示没有明显的相关性.研究结果为将来水脉泽的搜寻工作提供可能的选源指导.  相似文献   

5.
目前发现羟基脉泽的星系都为亮或极亮的红外星系,但在许多(极)亮红外星系中并未探测到羟基脉泽辐射,这可能意味着羟基脉泽寄主(极)亮红外星系具有某些独特的特性.文章利用Spitzer红外卫星的测光数据,研究羟基脉泽寄主星系的中红外特性.通过统计对比分析羟基脉泽寄主星系和非羟基脉泽寄主星系(即未探测到羟基脉泽辐射的星系)在3. 6μm、4. 5μm、5. 8μm、8μm和24μm波段的辐射光度和谱指数、中红外能谱分布,及其与羟基脉泽光度的关系,结果发现:(1)非羟基脉泽样本的3. 6μm辐射光度明显大于羟基脉泽样本;(2)羟基脉泽样本的谱指数较大,能谱分布的对比显示羟基脉泽的光谱更陡(8μm~24μm);(3)羟基脉泽光度与中红外24μm的光度存在较弱的正相关(R~0. 36),间接支持羟基脉泽辐射的远红外辐射抽运机制.  相似文献   

6.
收集目前发表的与活动星系核相关的所有水脉泽源,以及它们各个波段(从射电到X射线)的观测资料.在66个这类星系中,有40个源的观测资料较全,得到的谱能量分布图较好,便于进一步分析.它们的谱能量分布形态相似,最强辐射位于远红外波段(峰值出现在~ 60 μm处).对它们的谱能量分布图进行拟合积分,估计得到它们的热光度.热光度范围从1042到1046 ergs·s-1,且大多数(26/40)为~1044ergs·s-1,平均值为1044.4±0 1 ergs·s-1.对这40个源的子样本,进一步分析其脉泽辐射强度与脉泽寄主星系热光度间的可能的相关.结果显示,虽然弥散比较大,但脉泽辐射随热光度增加趋向于增强.对影响这一相关性的可能因素做进一步讨论.  相似文献   

7.
详细调研并收集了所有河外水脉泽寄主星系的射电观测资料(84个源).在6 cm和20 cm两个波段,"千脉泽"(其光度小于10个太阳光度)源的射电流量都大于"兆脉泽"源(其光度大于10个太阳光度).由收集的这两个波段的观测数据,首次导出了水脉泽星系的射电谱指数,α=0.87±0.11.比较水脉泽星系和没有检测到水脉泽的星系的谱指数,没有发现明显的差异.进一步分析水脉泽各向同性辐射光度与脉泽寄主星系射电强度,发现它们之间存在一个强相关,这与水脉泽辐射可能是对背景射电连续谱的放大的理论结果相吻合.  相似文献   

8.
收集了最新的河外水脉泽样本资料(截至2007.03),并计算给出这些源的部分物理参数.主要分析了水脉泽辐射和脉泽寄主星系的红外辐射之间的可能相关性.分析结果显示河外水脉泽源与银河系内脉泽源一样,水脉泽辐射光度和脉泽寄主星系的红外辐射光度存在相关性,即LH2O~10-9LFIR.  相似文献   

9.
活动星系核的高能辐射占了它们总辐射的相当大的比例。搜集了活动星系核的样本98个,通过分析谱指数、红移、流量密度来探讨活动星系核能谱演化。  相似文献   

10.
为了研究活动星系核喷流进动的物理机制,从文献中收集到23个有喷流进动周期(P)、B波段绝对星等(Mabs)和黑洞质量(Mbh)数据的活动星系核组成样本.用样本检验吸积盘驱动中心黑洞和喷流进动的盘致进动模型,观测到数据整体上符合理论预期的P、Mabs和Mbh之间的关系,但数据的弥散度较大,吸积盘的黏滞参数需取较大范围才能使理论范围覆盖所有的样本源.喷流进动也可能是由于星系核中心存在超大质量双黑洞.在此双黑洞模型下估算了样本源中双黑洞的距离,并将10个样本源的双黑洞距离和从文献中得到的星系核宽线区尺度对比,显示喷流进动周期大于106年的样本源的双黑洞距离可能大于星系核宽线区尺度.因此通过喷流进动的观测结果可以搜寻超大质量双黑洞候选体和限制双黑洞的参数.高质量的反响映射监测等进一步观测有望检验超大质量双黑洞系统的存在,帮助揭示喷流进动的物理机制.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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