Sriyasriti Acharya

Long-term variability in the context of helical jet model

We have carried out high resolution 3D relativistic MHD simulations of highly magnetized plasma column using the PLUTO code. In this work, we have confirmed the impact of axial wave-number on the dynamics of the plasma column including the growth of the instability and found that the column with maximum growth rate exhibits the maximum variability.

From the calculation of total integrated flux using a static particle spectra, we observed that the location of emitting region is different for different line of sight of the observer, clearly demonstrating the objective of helical jet model. In addition, the statistical estimates connect the dynamics with the emission features and support the helical jet picture as a model to explain the long term flux variation for a period of ~20 years.

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Figure: Three-slice representation of the plasma column density at t/tsc = 30 and 70 after kink mode perturbation for the Ref case. The colour bars show the plasma density and magnetic field lines strength. The cuts are taken at the planes (X = 0, Y = 0, Z = 0.5Lz).

Figure: Simulated light-curve for the Ref case where F_ν /Fν_sc is normalized to 8.27 × 10−24 and 2 × 10−25 for an observer making an angle of 20◦ and 45◦with respect to the axis of the plasma column, respectively. Here, t_beg = 20 t_sc and the vertical lines represent the error bar with SNR = 60.