Giant chromospheric jet observed with Hinode and magnetic reconnection model
Abstract
Heating of the solar chromosphere and corona is one of the long-standing puzzles in astronomy and also a key to understand the Sun-Earth connection through solar wind and EUV/X-ray radiation. A solar space telescope mission Hinode revealed that solar chromosphere is much more dynamic than had been thought and is full of tiny jets, which may be a key to resolve the puzzle of chromospheric and coronalheating. It has long been observed that H-alpha jets called surges often occur in the chromosphere. They have been believed to be produced by magnetic reconnection, which is an energy conversion mechanism from magnetic energy into thermal and kinetic energies of plasma when anti-parallel magnetic fields encounter and reconnect with each other. Hinode's new chromospheric observations (with Calcium II H broad band filter) revealed that jets are ubiquitous in the chromosphere and some of the jets show evidence of magnetic reconnection. However, there have not been simultaneous observations of the chromospheric jets at X-ray, EUV, and Optical (at Calcium II H line) wavelengths until now. Here we report first multi-wavelength observations of a chromospheric jet with Solar Optical Telescope (SOT) and X-Ray Telescope (XRT) on board Hinode and TRACE 195A filter. With its unprecedented high quality instruments at both optical and X-rays, Hinode discovered a beautiful, giant jet with both cool (104 K) and hot (5x106 K) components at the solar limb. TRACE satellite also observed the same jet with EUV telescope and revealed the existence of both hot (106 K) and cool (unknown temperature) components. These data set are probably the best multi-wavelength observations of solar jets until now. We also performed magnetohydrodynamic simulation of the jet based on the reconnection model and found that it can explain various observational facts very well. It has often been argued that some of solar jets are produced by magnetic reconnection, but previous observations had a limitation on spatial and temporal resolutions and temperature coverage. Using these new data and twodimensional magnetohydrodynamic simulations of the jet, we showed, for the first time, how hot and cool jets are heated and accelerated during the reconnection, including associated generation of Alfvén waves. This jet formation dynamics would show a proto-tyep of reconnection e model of solar jets and can be applied for other small jets discovered by Hinode, which might heat the chromosphere and corona.
- Publication:
-
37th COSPAR Scientific Assembly
- Pub Date:
- 2008
- Bibcode:
- 2008cosp...37.2239N