在活躍星系核OH-010的噴流中檢測絕熱膨脹與能量均分兩噴流模型

• Main Authors: Huang, Ting-Yu, 黃廷宇
• Other Authors: Albert Kong
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/00780444784718443429

碩士 === 國立清華大學 === 物理系 === 102 === The quasar OH-010 is studied using data obtained by the Very Long Baseline Array (VLBA)at 15.4 GHz from the MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) archive and light curves from single dish observations at 4.8, 8, 14.5, 22, 37,and 90 GHz. One goal of this works is to examine the applicability of two commonly used assumptions for active galactic nuclei jets: an adiabatic jet (Marscher &; Gear 1985) or a jet which holds equipartition between particle and field energies (Blandford &; Konigl 1979) to the behavior of this source. We find a clear power law signature in two VLBI (Very Long Baseline Interferometry) components and found that for component 4, it is consistent with having initial equipartition and remains to be so along the jet. Component 3 in contrast can be explained by either case but it does not have initial equipartition between particle and magnetic field. Connecting VLBA data with light curve data revealed that both VLBI components 2 and 3 may be related to two flares in the light curve. We propose that such behavior can be explained by a jet which has an initial parabolic structure where components exhibit accelerated motion followed by a transition to a conical structure in which components travel at constant velocity. We find this transition to have properties similar to a recollimation shock and the overall finding is reminiscent of the jet in M87. The finding of a quasi-stationary component on VLBI maps ∼ 0.29 mas downstream of the radio core also supports this scenario.