The disk-jet symbiosis is a fundamental problem in our understanding of the Active Galactic Nuclei （AGN）. We explore the relation between the Doppler factors d of the jet of blazars and their broad line region lumin...The disk-jet symbiosis is a fundamental problem in our understanding of the Active Galactic Nuclei （AGN）. We explore the relation between the Doppler factors d of the jet of blazars and their broad line region luminosity LBLR. Since different methods measuring δ might differ substantially, we use data obtained from 3 independent methods and compile 3 samples of sources for each of them, respectively. Two samples consist of blazars, that is, Flat Spectrum Radio Quasars （FSRQs） and BL Lacertae objects （BL Lacs）, and the other consists of BL Lacs. dis one of the most important jet properties and LBLR is thought to be the proxy of the accretion power. Correlation analysis to these samples shows that there exists a significant correlation between δ and LBLR, which supports the idea that the jet powering process is closely linked with the accretion process and provides new evidence for disk-jet connection. Furthermore, the results are consistent with the idea that the Blandford-Znajek mechanism is sufficient for BL Lacs and a hybrid model is needed for FSRQs.展开更多
[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new ...[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new generation weather radar in Harbin from 2002 to 2007, the features of the reflectivity factors of the cold front cloud system were summarized. [Result] The cloud formed by the cold front was in banded form in general. However, there was void in the cloud and its intensity was uneven. Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest. With the changes of month, the feature of the reflective rate also changed. In winter, the cold front cloud was in layer form. The feature of the reflectivity factors was weak and in large area. However, the structure was loose and there was space in the echo. Among them, there were several strong echoes. Strong convection cell echo formed in the two sides of the cold front, and it moved with the entire cloud belt. When the dry cold front moved, regional strong convective current formed, mainly by convective cloud and small echo area. Generally, the changes of the wind direction can not be expounded from the radial velocity. However, the intensity of the convection cell was distinct, 'three-body scattering', 'side lobe echo', and 'weak echo', as well as features of super convection cell. [Conclusion] The study provided positive role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10973034,10978019,11043002)the State Key Development Program for Basic Research of China(Grant No. 2009CB824800)the Provincial Natural Science Foundation of Yunnan (Grant No.09401145,1012456)
文摘The disk-jet symbiosis is a fundamental problem in our understanding of the Active Galactic Nuclei （AGN）. We explore the relation between the Doppler factors d of the jet of blazars and their broad line region luminosity LBLR. Since different methods measuring δ might differ substantially, we use data obtained from 3 independent methods and compile 3 samples of sources for each of them, respectively. Two samples consist of blazars, that is, Flat Spectrum Radio Quasars （FSRQs） and BL Lacertae objects （BL Lacs）, and the other consists of BL Lacs. dis one of the most important jet properties and LBLR is thought to be the proxy of the accretion power. Correlation analysis to these samples shows that there exists a significant correlation between δ and LBLR, which supports the idea that the jet powering process is closely linked with the accretion process and provides new evidence for disk-jet connection. Furthermore, the results are consistent with the idea that the Blandford-Znajek mechanism is sufficient for BL Lacs and a hybrid model is needed for FSRQs.
文摘[Objective] The aim was to summarize the characteristics of refelectivity factors of Doppler radar of the cold front cloud system. [Method] Judging from the characteristics of reflectivity factors, by dint of the new generation weather radar in Harbin from 2002 to 2007, the features of the reflectivity factors of the cold front cloud system were summarized. [Result] The cloud formed by the cold front was in banded form in general. However, there was void in the cloud and its intensity was uneven. Most fast moving cold front was long and narrow banded echo and basically the radial velocity turned from northwest wind to southwest. With the changes of month, the feature of the reflective rate also changed. In winter, the cold front cloud was in layer form. The feature of the reflectivity factors was weak and in large area. However, the structure was loose and there was space in the echo. Among them, there were several strong echoes. Strong convection cell echo formed in the two sides of the cold front, and it moved with the entire cloud belt. When the dry cold front moved, regional strong convective current formed, mainly by convective cloud and small echo area. Generally, the changes of the wind direction can not be expounded from the radial velocity. However, the intensity of the convection cell was distinct, 'three-body scattering', 'side lobe echo', and 'weak echo', as well as features of super convection cell. [Conclusion] The study provided positive role for the application of Doppler radar in the surveillance of weather in Heilongjiang Province.
