VLBI observations of seven BL Lacertae objects from RGB sample
VLBI observations of seven BL Lacertae objects from RGB sample
复制标题
DOI：
10.1051/0004-6361:20066754
复制
发表时间：
2007-04
影响因子：
6.5
通讯作者：
Zhongzu Wu;Dong-Rong Jiang;M. Gu;Yi Liu
中科院分区：
文献类型：
--
作者：
Zhongzu Wu;Dong-Rong Jiang;M. Gu;Yi Liu
我们提出了EVN观测的7 BL Lac对象从RGB样本中选择。为了研究BL Lac天体的内禀辐射特性，我们估算了170个BL Lac天体的VLA或MERLIN核的多普勒因子和408 MHz的总光度。然后，通过使用估计的多普勒因子来计算固有（共动）同步加速器峰值频率。假设洛伦兹因子为5，则射流的视角受到约束。七个源的高分辨率VLBI图像都显示了核心喷流结构。利用VLBI观测资料对三个源的自行进行了估计，发现它们的视速度都随着分量到核的距离的增加而增加。在我们的BL拉克样本中，LBL的多普勒因子系统地大于IBL和HBL的多普勒因子。我们发现一个显着的反相关之间的总408 MHz的光度和固有的同步峰值频率。然而，散射比blazar序列大得多。此外，我们还发现视角与本征同步峰值频率之间存在显著的正相关关系。BL Lac天体在视角上显示出连续的分布。虽然LBL具有比IBL和HBL更小的视角，但IBL与HBL相当。我们的结论是，本征同步辐射峰值频率不仅与本征无线电功率（虽然有很大的散射），但也对本样品的视角。
We present EVN observations of seven BL Lac objects selected from the RGB sample. To investigate the intrinsic radiation property of BL Lac objects, we estimated the Doppler factor with the VLA or MERLIN core and the total 408 MHz luminosity for a sample of 170 BL Lac objects. The intrinsic ( comoving) synchrotron peak frequency was then calculated by using the estimated Doppler factor. Assuming a Lorentz factor of 5, the viewing angle of jets was constrained. The high-resolution VLBI images of seven sources all show a core-jet structure. We estimated the proper motions of three sources with the VLBI archive data, and find that the apparent speed increases with the distance of components to the core for all of them. In our BL Lacs sample, the Doppler factor of LBLs is systematically larger than that of IBLs and HBLs. We find a significant anti-correlation between the total 408 MHz luminosity and the intrinsic synchrotron peak frequency. However, the scatter is much larger than for the blazar sequence. Moreover, we find a significant positive correlation between the viewing angle and the intrinsic synchrotron peak frequency. The BL Lac objects show a continuous distribution on the viewing angle. While LBLs have a smaller viewing angle than that of IBLs and HBLs, IBLs are comparable to HBLs. We conclude that the intrinsic synchrotron peak frequency is not only related to the intrinsic radio power ( though with a large scatter), but also to the viewing angle for the present sample.