EXTREMELY LARGE EUV LATE PHASE OF SOLAR FLARES

Journal Article · Fri Mar 20 04:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/802/1/35· OSTI ID:22522033

Liu, Kai; Wang, Yuming; Liu, Rui; Shen, Chenglong ^[1]; Zhang, Jie ^[2]; Cheng, Xin ^[3]

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1. Key Laboratory of Geospace Environment, University of Science and Technology of China, No. 96 Jinzhai Road, Hefei, Anhui Province 230026 (China)
2. School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, MSN 6A2, Fairfax, VA 22030 (United States)
3. School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China)

The second peak in the Fe xvi 33.5 nm line irradiance observed during solar flares by the Extreme-Ultraviolet Variability Experiment (EVE) is known as the EUV late phase. Our previous paper in 2013 by Liu et al. found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different from the post-flare loops (PFLs), and we also proposed that a long cooling process without additional heating could explain the late phase. In this paper, we define the extremely large late phase because it not only has a bigger peak in the warm 33.5 irradiance profile, but also releases more EUV radiative energy than the main phase. Through detailed inspection of the EUV images from three points of view, it was discovered that aside from the later-phase loop arcades, the main contributor of the extremely large late phase is a hot structure that fails to erupt. This hot structure is identified as a flux rope, which is quickly energized by the flare reconnection and later on continuously produces the thermal energy during the gradual phase. Together with the late-phase loop arcades, the flux rope failing to erupt with the additional heating create the extremely large EUV late phase.

• OSTI ID: 22522033
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 802; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
EXTREME ULTRAVIOLET RADIATION
HEATING
IMAGES
MAGNETIC FLUX
RADIANT FLUX DENSITY
SOLAR FLARES
SUN