An Observational Test of Solar Plasma Heating by Magnetic Flux Cancellation
arXiv:2005.07953 · doi:10.3847/1538-4357/ab93ca
Abstract
Recent observations suggest that magnetic flux cancellation may play a crucial role in heating the Sun's upper atmosphere (chromosphere, transition region, corona). Here, we intended to validate an analytic model for magnetic reconnection and consequent coronal heating, driven by a pair of converging and cancelling magnetic flux sources of opposite polarities. For this test, we analyzed photospheric magnetic field and multi-wavelength UV/EUV observations of a small-scale flux cancellation event in a quiet-Sun internetwork region over a target interval of 5.2 hr. The observed cancellation event exhibits a converging motion of two opposite-polarity magnetic patches on the photosphere and red-shifted Doppler velocities (downflows) therein consistently over the target interval, with a decrease in magnetic flux of both polarities at a rate of 10 Mx s. Several impulsive EUV brightenings, with differential emission measure values peaked at 1.6-2.0 MK, are also observed in the shape of arcades with their two footpoints anchored in the two patches. The rate of magnetic energy released as heat at the flux cancellation region is estimated to be in the range of (0.2-1)10 erg s over the target interval, which can satisfy the requirement of previously reported heating rates for the quiet-Sun corona. Finally, both short-term (a few to several tens of minutes) variations and long-term (a few hours) trends in the magnetic energy release rate are clearly shown in the estimated rate of radiative energy loss of electrons at temperatures above 2.0 MK. All these observational findings support the validity of the investigated reconnection model for plasma heating in the upper solar atmosphere by flux cancellation.
arXiv comment17 pages, 6 figures, accepted for publication in ApJ
References in corpus (42)
- The Interface Region Imaging Spectrograph (IRIS)
- Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection
- Differential Emission Measures from the Regularized Inversion of Hinode and SDO data
- Prevalence of Small-scale Jets from the Networks of the Solar Transition Region and Chromosphere
- Sunrise: instrument, mission, data and first results
- The Imaging Magnetograph eXperiment (IMaX) for the Sunrise balloon-borne solar observatory
- Imaging coronal magnetic-field reconnection in a solar flare
- Temporal aspects and frequency distributions of solar soft X-ray flares
- A Contemporary View of Coronal Heating
- CHIANTI - an atomic database for emission lines - Paper XV: Version 9, improvements for the X-ray satellite lines
- Plasmoid Ejections and Loop Contractions in an Eruptive M7.7 Solar Flare: Evidence of Particle Acceleration and Heating in Magnetic Reconnection Outflows
- Simultaneous Observation of Reconnection Inflow and Outflow Associated with the 2010 August 18 Solar Flare
- Reconnection Outflows and Current Sheet Observed with Hinode/XRT in the 2008 April 9 "Cartwheel CME" Flare
- Three-dimensional magnetic reconnection regimes: A review
- The second flight of the SUNRISE balloon-borne solar observatory: overview of instrument updates, the flight, the data and first results
- Simultaneous observation of a flux rope eruption and magnetic reconnection during an X-class solar flare
- A Cancellation Nanoflare Model for Solar Chromospheric and Coronal Heating
- Magnetic reconnection between small-scale loops observed with the New Vacuum Solar Telescope
- A Reconnecting Current Sheet Imaged in A Solar Flare
- Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields
- Magnetic Flux Cancellation in Ellerman Bombs
- Extreme Ultraviolet Imaging of Three-dimensional Magnetic Reconnection in a Solar Eruption
- Fine-scale explosive energy release at sites of prospective magnetic flux cancellation in the core of the solar active region observed by Hi-C 2.1, IRIS and SDO
- Multiple Plasmoid Ejections and Associated Hard X-ray Bursts in the 2000 November 24 Flare
- A magnetic reconnection event in the solar atmosphere driven by relaxation of a twisted arch filament system
- Theory of magnetic reconnection in solar and astrophysical plasmas
- Trigger Mechanism of Solar Subflares in a Braided Coronal Magnetic Structure
- Tether-cutting Reconnection between Two Solar Filaments Triggering Outflows and a Coronal Mass Ejection
- A Cancellation Nanoflare Model for Solar Chromospheric and Coronal Heating II. 2D Theory and Simulations
- Imaging Spectropolarimetry with IBIS: Evolution of Bright Points in the Quiet Sun
- Evaluating (and Improving) Estimates of the Solar Radial Magnetic Field Component from Line-of-Sight Magnetograms
- Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. II. Nanoflare Trains
- Estimation of the magnetic flux emergence rate in the quiet Sun from Sunrise data
- On The Relationship Between Magnetic Cancellation and UV Burst Formation
- Observations of The Magnetic Reconnection Signature of An M2 Flare on 2000 March 23
- A Cancellation Nanoflare Model for Solar Chromospheric and Coronal Heating III. 3D Simulations and Atmospheric Response
- Interaction between Granulation and Small-Scale Magnetic Flux Observed by Hinode
- Two-stage energy release process of a confined flare with double HXR peaks
- Observational Evidence of Magnetic Reconnection Associated with Magnetic Flux Cancellation
- Relationship between supergranulation flows, magnetic cancellation and network flares
- Magnetic filed dynamics and varying plasma emission in large coronal loops
- Cancellation of Small-Scale Magnetic Features