...
首页> 外文期刊>The Astrophysical journal >RELATIVISTIC DOPPLER BEAMING AND MISALIGNMENTS IN AGN JETS
【24h】

RELATIVISTIC DOPPLER BEAMING AND MISALIGNMENTS IN AGN JETS

机译:AGN射箭中的相对论多普勒束发和误解

获取原文
   

获取外文期刊封面封底 >>

       

摘要

Radio maps of active galactic nuclei often show linear features, called jets, on both parsec and kiloparsec scales. These jets supposedly possess relativistic motion and are oriented close to the line of sight of the observer, and accordingly the relativistic Doppler beaming makes them look much brighter than they really are in their respective rest frames. The flux boosting due to the relativistic beaming is a very sensitive function of the jet orientation angle, as seen by the observer. Sometimes, large bends are seen in these jets, with misalignments being 90° or more, which might imply a change in the orientation angle that should cause a large change in the relativistic beaming factor. Hence, if relativistic beaming does play an important role in these jets such large bends should usually show high contrast in the brightness of the jets before and after the bend. It needs to be kept in mind that sometimes a small intrinsic change in the jet angle might appear as a much larger misalignment due to the effects of geometrical projection, especially when seen close to the line of sight. What really matters are the initial and final orientation angles of the jet with respect to the observer's line of sight. Taking the geometrical projection effects properly into account, we calculate the consequences of the presumed relativistic beaming and demonstrate that there ought to be large brightness ratios in jets before and after the observed misalignments.
机译:活跃银河原子核的无线电图通常在秒差距和千秒尺度上都显示出线性特征,称为射流。据推测,这些喷气机具有相对论运动,并且靠近观察者的视线定向,因此,相对论多普勒光束使它们看上去比它们各自静止框架中的亮度要明亮得多。如观察者所见,由于相对论性射束引起的通量增加是射流取向角的非常敏感的函数。有时,在这些喷口中会看到较大的弯曲,未对准的角度为90°或更大,这可能意味着取向角的变化,这将导致相对论光束系数发生较大的变化。因此,如果相对论光束在这些射流中确实起着重要作用,那么大的弯曲通常应该在弯曲之前和之后的射流的亮度上显示出高对比度。需要牢记的是,有时由于几何投影的影响,尤其是当靠近视线时,喷射角的小内在变化可能会表现为更大的失准。真正重要的是射流相对于观察者视线的初始和最终定向角。考虑到适当的几何投影效果,我们计算了假定的相对论光束的结果,并证明在观察到的未对准前后,射流中应该有较大的亮度比。

著录项

获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号