Dynamical Modelling and Emission Signatures of a Candidate Dual AGN with Precessing Radio Jets
Dynamical Modelling and Emission Signatures of a Candidate Dual AGN with Precessing Radio Jets
复制标题
具有进动无线电射流的候选双 AGN 的动态建模和发射特征
DOI：
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发表时间：
2022
影响因子：
4.8
通讯作者：
P. Kharb
中科院分区：
文献类型：
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作者：
Gourab Giri;Ravi Pratap Dubey;K. Rubinur;B. Vaidya;P. Kharb
在本文中，我们模拟了观测到的S形射电源（2MASX J12032061+131931）由于旋进喷流的动力学和发射特性（存在辐射损失和扩散激波加速）。在这方面，我们已经进行了高分辨率的三维磁流体动力学（MHD）模拟旋进射流在银河系环境中。我们显示了一个独特的S形的外观与两个明亮的热点时，弓形激波区域随着时间的推移而减弱。所形成的形貌对参数选择敏感。螺旋射流和周围介质之间的相互作用的增加以及由于MHD不稳定性引起的射流减速也极大地影响了所得到的结构。因此，运动学模型必须校正这些减速效应，以充分预测的进动参数。合成光谱指数图显示，喷流侧和前缘具有相对陡峭的光谱指数值比喷流脊线，而热点显示平坦的光谱指数值。射流也被发现是高度线性极化（高达76%）和磁场线，在一般情况下，遵循射流轨迹，这是由于射流周围介质的相互作用。在这种情况下，扩散冲击使结构在其演化过程中保持活跃。此外，我们已经证明，这些星系偏离显着的“均分”近似导致的光谱和动力学年龄的差异。
In this paper, we have modelled the dynamical and emission properties (in the presence of radiative losses and diffusive shock acceleration) of an observed S-shaped radio source (2MASX J12032061+131931) due to a precessing jet. In this regard, we have performed high-resolution 3D magnetohydrodynamic (MHD) simulations of a precessing jet in a galactic environment. We show the appearance of a distinct S-shape with two bright hotspots when the bow shock region weakens over time. The formed morphology is sensitive to the parameter selections. The increased interaction between the helical jet and the ambient medium and the deceleration of the jet due to MHD instabilities also greatly affect the resulting structure. Hence, kinematic models must be corrected for these deceleration effects in order to adequately predict the precession parameters. The synthetic spectral index map shows that the jet side and leading edges possess relatively steeper spectral index values than the jet ridge lines, whereas the hotspots show flat spectral index values. The jets are also found to be highly linearly polarized (up to 76%) and the magnetic field lines, in general, follow the jet locus which is formed due to the jet-ambient medium interaction. Diffusive shocks, in this context, keep the structure active during its course of evolution. Furthermore, we have demonstrated that these galaxies deviate significantly from the ‘equipartition’ approximation leading to a discrepancy in their spectral and dynamical age.