PLASMA MOTIONS AND HEATING BY MAGNETIC RECONNECTION IN A 2007 MAY 19 FLARE

Journal Article · Thu Nov 10 00:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/741/2/107; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21612687

Hara, Hirohisa; Watanabe, Tetsuya ^[1]; Harra, Louise K; Leonard Culhane, J ^[2]

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1. National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)
2. UCL-Mullard Space Science Laboratory, Holmbury, St Mary, Dorking, Surrey RH5 6NT (United Kingdom)

Based on scanning spectroscopic observations with the Hinode EUV imaging spectrometer, we have found a loop-top hot source, a fast jet nearby, and an inflow structure flowing to the hot source that appeared in the impulsive phase of a long-duration flare at the disk center on 2007 May 19. The hot source observed in Fe XXIII and Fe XXIV emission lines has the electron temperature of 12 MK and density of 1 Multiplication-Sign 10{sup 10} cm{sup -3}. It shows excess line broadening, which exceeds the thermal Doppler width by {approx}100 km s{sup -1}, with a weak redshift of {approx}30 km s{sup -1}. We have also observed a blueshifted faint jet whose Doppler velocity exceeds 200 km s{sup -1} with an electron temperature of 9 MK. Coronal plasmas with electron temperature of 1.2 MK and density of 2.5 Multiplication-Sign 10{sup 9} cm{sup -3} that flow into the loop-top region with a Doppler velocity of 20 km s{sup -1} have been identified in the Fe XII observation. They disappeared near the hot source, possibly by being heated to the hotter faint jet temperature. From the geometrical relationships of these phenomena, we conclude that they provide evidence for magnetic reconnection that occurs near the loop-top region. The estimated reconnection rate is 0.05-0.1, which supports the Petschek-type magnetic reconnection. Further supporting evidence for the presence of the slow-mode and fast-mode MHD shocks in the reconnection geometry is given based on the observed quantities.

• OSTI ID: 21612687
• Journal Information: Astrophysical Journal, Vol. 741, Issue 2; Other Information: DOI: 10.1088/0004-637X/741/2/107; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
ELECTRON TEMPERATURE
IRON
LINE BROADENING
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
PLASMA
RED SHIFT
SOLAR CORONA
SOLAR FLARES
SPECTROMETERS
SUN
ULTRAVIOLET RADIATION
ATMOSPHERES
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUID MECHANICS
HYDRODYNAMICS
MAIN SEQUENCE STARS
MEASURING INSTRUMENTS
MECHANICS
METALS
PHYSICS
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
STARS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR FLARES
TRANSITION ELEMENTS