FLARES AND THEIR UNDERLYING MAGNETIC COMPLEXITY

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/726/1/12· OSTI ID:21567514

Engell, Alexander J; Golub, Leon; Korreck, Kelly ^[1]; Siarkowski, Marek; Gryciuk, Magda; Sylwester, Janusz; Sylwester, Barbara ^[2]; Cirtain, Jonathan ^[3]

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge MA 02138 (United States)
2. Space Research Center, Polish Academy of Sciences, Kopernika 11, 51-622 Wroclaw (Poland)
3. Marshall Space Flight Center NASA, Mail Code: VP62, Marshall Space Flight Center, AL 35812 (United States)

SphinX (Solar PHotometer IN X-rays), a full-disk-integrated spectrometer, observed 137 flare-like/transient events with active region (AR) 11024 being the only AR on disk. The Hinode X-Ray Telescope (XRT) and Solar Optical Telescope observe 67 of these events and identified their location from 12:00 UT on July 3 through 24:00 UT 2009 July 7. We find that the predominant mechanisms for flares observed by XRT are (1) flux cancellation and (2) the shearing of underlying magnetic elements. Point- and cusp-like flare morphologies seen by XRT all occur in a magnetic environment where one polarity is impeded by the opposite polarity and vice versa, forcing the flux cancellation process. The shearing is either caused by flux emergence at the center of the AR and separation of polarities along a neutral line or by individual magnetic elements having a rotational motion. Both mechanisms are observed to contribute to single- and multiple-loop flares. We observe that most loop flares occur along a large portion of a polarity inversion line. Point- and cusp-like flares become more infrequent as the AR becomes organized with separation of the positive and negative polarities. SphinX, which allows us to identify when these flares occur, provides us with a statistically significant temperature and emission scaling law for A and B class flares: EM = 6.1 x 10{sup 33} T{sup 1.9{+-}0.1}.

• OSTI ID: 21567514
• Journal Information: Astrophysical Journal, Vol. 726, Issue 1; Other Information: DOI: 10.1088/0004-637X/726/1/12; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
EMISSION
PHOTOMETERS
PHOTOSPHERE
SCALING LAWS
SOLAR CORONA
SOLAR FLARES
TOPOLOGY
X RADIATION
ATMOSPHERES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
MATHEMATICS
MEASURING INSTRUMENTS
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR FLARES