ﻻ يوجد ملخص باللغة العربية
Recent radio VLBI observations of the relativistic jet in M87 radio galaxy have shown a triple-ridge structure that consists of the conventional limb-brightened feature and a central narrow ridge. Motivated by these observations, we examine a steady axisymmetric force-free model of a jet driven by the central black hole (BH) with its electromagnetic structure being consistent with general relativistic magnetohydrodynamic simulations, and find that it can produce triple-ridge images even if we assume a simple Gaussian distribution of emitting electrons at the base of the jet. We show that the fluid velocity field associated with the electromagnetic field produces the central ridge component due to the relativistic beaming effect, while the limb-brightened feature arises due to strong magnetic field around the jet edge which also induces the electrons to be dense there. We also show that the computed image strongly depends on the electromagnetic field structure, viewing angle, and parameters related to the electrons spatial distribution at the jet base. This study will help constraining the non-thermal electron injection mechanism of BH jets and be complementary to theoretical analyses of the upcoming data of Event Horizon Telescope.
The class of Double-Double Radio Galaxies (DDRGs) relates to episodic jet outbursts. How various regions and components add to the total intensity in radio images is less well known. In this paper we synthesize synchrotron images for DDRGs based on s
We present results from a multi-wavelength analysis searching for multiple AGN systems in nearby (z<0.077) triple galaxy mergers. Combining archival Chandra, SDSS, WISE, and VLA observations, we quantify the rate of nearby triple AGN, as well as inve
We present 15 GHz stacked VLBA images of 373 jets associated with active galactic nuclei (AGN) having at least five observing epochs within a 20 yr time interval 1994-2015 from the MOJAVE programme and/or its precursor, the 2 cm VLBA Survey. These da
In this paper, we investigate the acceleration in relativistic jets of high-energy proton preaccelerated in the magnetosphere of a supermassive black hole. The proton reaches maximum energy when passing the total potential difference of $U$ between t
We present results from our X-ray analysis of the first systematic search for triple AGN in nearby (z<0.077) triple galaxy mergers. We analyze archival Chandra observations of 7 triple galaxy mergers with BAYMAX (Bayesian Analysis of Multiple AGN in