KINEMATICS AND FINE STRUCTURE OF AN UNWINDING POLAR JET OBSERVED BY THE SOLAR DYNAMIC OBSERVATORY/ATMOSPHERIC IMAGING ASSEMBLY
- National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China)
- Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China)
- Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)
We present an observational study of the kinematics and fine structure of an unwinding polar jet, with high temporal and spatial observations taken by the Atmospheric Imaging Assembly on board the Solar Dynamic Observatory and the Solar Magnetic Activity Research Telescope. During the rising period, the shape of the jet resembled a cylinder with helical structures on the surface, while the mass of the jet was mainly distributed on the cylinder's shell. In the radial direction, the jet expanded successively at its western side and underwent three distinct phases: the gradually expanding phase, the fast expanding phase, and the steady phase. Each phase lasted for about 12 minutes. The angular speed of the unwinding motion of the jet and the twist transferred into the outer corona during the eruption are estimated to be 11.1 x 10{sup -3} rad s{sup -1} (period = 564 s) and 1.17-2.55 turns (or 2.34-5.1{pi}), respectively. On the other hand, by calculating the azimuthal component of the magnetic field in the jet and comparing the free energy stored in the non-potential magnetic field with the jet's total energy, we find that the non-potential magnetic field in the jet is enough to supply the energy for the ejection. These new observational results strongly support the scenario that the jets are driven by the magnetic twist, which is stored in the twisted closed field of a small bipole, and released through magnetic reconnection between the bipole and its ambient open field.
- OSTI ID:
- 21562547
- Journal Information:
- Astrophysical Journal Letters, Vol. 735, Issue 2; Other Information: DOI: 10.1088/2041-8205/735/2/L43; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
AN INTRIGUING CHROMOSPHERIC JET OBSERVED BY HINODE: FINE STRUCTURE KINEMATICS AND EVIDENCE OF UNWINDING TWISTS
A STANDARD-TO-BLOWOUT JET