Fine Structure of the Core of the Blazar OJ 287. II. Wavelength 2 cm
| Autor: | S. S. Sivakon, L. I. Matveyenko |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Brightness Jet (fluid) 010308 nuclear & particles physics Nozzle Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Vortex Core (optical fiber) Space and Planetary Science Bulge Bipolar outflow 0103 physical sciences Precession 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| Zdroj: | Astronomy Letters. 44:421-441 |
| ISSN: | 1562-6873 1063-7737 |
| Popis: | We have continued our studies of the fine structure of the active region in the blazar OJ 287 at wavelength λ = 2cm with a resolution of 20 μas, the epochs of 1995–2017. We have identified fragments of two arms along which the surrounding plasma comes to the nozzle. The brightness temperature of the flows rises as the nozzle is approached to Tb ⩽ 1012 K. The high-velocity bipolar outflow surrounded by lowvelocity components carries away an excess angular momentum as it is accumulated. The high collimation and helicity of the flows are determined by rotation and precession, respectively. Ring currents responsible for the longitudinal magnetic fields are excited in the flows. The jet and counterjet are a mirror reflection of each other; the difference in sizes is determined by the acceleration/deceleration of the flows along/opposite to the magnetic field. The velocity of the high-velocity outflow is v ⩽ 0.06 c. The brightness temperature of the nozzle reaches Tb ⩽ 1014 K. The spectral index of the southern and northern nozzles is α ≈ 0.66 and ≈0.4, respectively; the difference is determined by absorption in the bulge. The separation between the nozzles is 12 μas or 0.05 pc. The central region of reduced brightness with a diameter ∅ ≈ 3.6 pc corresponds to the bulge inclined toward the jet at an angle of 65° to the plane of the sky. The counterjet is ejected toward the observer; the jet is ejected in the opposite direction and is visible outside the bulge from a distance of 1.5 pc. The structure and kinematics of the bulge correspond to a vortex nature. An enhanced supply of matter from the northern arm in the middle of 2000 increased the activity of the low-velocity nozzle. A secondary vortex located at a distance of 0.28 mas (1.3 pc) was formed. The high-velocity flow is ejected in a direction of −110°. |
| Databáze: | OpenAIRE |
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