title: Extreme ultraviolet imaging of three-dimensional magnetic reconnection in a solar eruption.
abstract: Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively, and it is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from ∼1 to ≥5 MK. Shortly afterwards, warm flare loops (∼3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magnetic reconnection in a three-dimensional configuration and reveal its origin.
authors.affiliation: School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Sun
authors.affiliation: School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China.
authors.forename: X
authors.identifier: 0000000328377136
authors.initials: X
authors.lastname: Cheng
authors.affiliation: School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China.
authors.forename: M D
authors.initials: MD
authors.lastname: Ding
authors.affiliation: School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
authors.affiliation: School of Mathematics and Statistics, University of St Andrews, Fife, KY16 9SS Scotland, UK.
authors.forename: E R
authors.initials: ER
authors.lastname: Priest
authors.affiliation: School of Mathematics and Statistics, University of St Andrews, Fife, KY16 9SS Scotland, UK.
authors.forename: C E
authors.initials: CE
authors.lastname: Parnell
authors.affiliation: Department of Mathematical Sciences, Durham University, Durham DH1 3LE, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Edwards
authors.affiliation: School of Physics, Astronomy and Computational Sciences, George Mason University, Fairfax, Virginia 22030, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China.
authors.forename: P F
authors.initials: PF
authors.lastname: Chen
authors.affiliation: School of Astronomy and Space Science, Nanjing University, Nanjing 210093, China.
authors.forename: C
authors.initials: C
authors.lastname: Fang