6533b830fe1ef96bd1297091

RESEARCH PRODUCT

Reconnection nanojets in the solar corona

Fabio RealeFabio RealePaolo PaganoA. PetraliaPatrick AntolinPatrick AntolinPaola Testa

subject

Physics010504 meteorology & atmospheric sciencesMagnetic energyDASAstronomy and AstrophysicsMagnetic reconnectionAstrophysics01 natural sciencesNanoflaresMagnetic fieldQC PhysicsPhysics::Space Physics0103 physical sciencesCoronal heatingQB AstronomyAstrophysics::Solar and Stellar Astrophysicssolar corona coronal heating magnetic reconnection010303 astronomy & astrophysicsQCQB0105 earth and related environmental sciences

description

P.A. acknowledges STFC support from grant numbers ST/R004285/2 and ST/T000384/1 and support from the International Space Science Institute, Bern, Switzerland to the International Teams on ‘Implications for coronal heating and magnetic fields from coronal rain observations and modeling’ and ‘Observed Multi-Scale Variability of Coronal Loops as a Probe of Coronal Heating’. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 647214). P.T. was also supported by contracts 8100002705 and SP02H1701R from Lockheed-Martin to the Smithsonian Astrophysical Observatory (SAO), and NASA contract NNM07AB07C to the SAO. The solar corona is shaped and mysteriously heated to millions of degrees by the Sun’s magnetic field. It has long been hypothesized that the heating results from a myriad of tiny magnetic energy outbursts called nanoflares, driven by the fundamental process of magnetic reconnection. Misaligned magnetic field lines can break and reconnect, producing nanoflares in avalanche-like processes. However, no direct and unique observations of such nanoflares exist to date, and the lack of a smoking gun has cast doubt on the possibility of solving the coronal heating problem. From coordinated multi-band high-resolution observations, we report on the discovery of very fast and bursty nanojets, the telltale signature of reconnection-based nanoflares resulting in coronal heating. Using state-of-the-art numerical simulations, we demonstrate that the nanojet is a consequence of the slingshot effect from the magnetically tensed, curved magnetic field lines reconnecting at small angles. Nanojets are therefore the key signature of reconnection-based coronal heating in action. Postprint Peer reviewed

10.1038/s41550-020-1199-8http://hdl.handle.net/10447/490145