Dispersal of G-band bright points at different longitudinal magnetic field strengths

Abstract

G-band bright points (GBPs) are thought to be the foot-points of magnetic flux tubes. The aim of this paper is to investigate the relation between the diffusion regimes of GBPs and the associated longitudinal magnetic field strengths. Two high resolution observations of different magnetized environments were acquired with the Hinode/Solar Optical Telescope. Each observation was recorded simultaneously with G-band filtergrams and Narrow-band Filter Imager (NFI) Stokes I and V images. GBPs are identified and tracked automatically, and then categorized into several groups by their longitudinal magnetic field strengths, which are extracted from the calibrated NFI magnetograms using a point-by-point method. The Lagrangian approach and the distribution of diffusion indices approach are adopted separately to explore the diffusion regime of GBPs for each group. It is found that the values of diffusion index and diffusion coefficient both decrease exponentially with the increasing longitudinal magnetic field strengths whichever approach is used. The empirical formulas deduced from the fitting equations are proposed to describe these relations. Stronger elements tend to diffuse more slowly than weak elements, independently of the magnetic flux of the surrounding medium. This may be because the magnetic energy of stronger elements is not negligible compared with the kinetic energy of the gas, and therefore the flows cannot perturb them so easily.Yang

arXiv comment10 pages, 7 figures

References in corpus (21)

• Heating of the Solar Chromosphere and Corona by Alfven Wave Turbulence
• Observational manifestations of solar magneto-convection -- center-to-limb variation
• Bright points in the inter-network quiet Sun
• Hinode Observations of Magnetic Elements in Internetwork Areas
• Magnetic properties of G-band bright points in a sunspot moat
• Solar Flares as Cascades of Reconnecting Magnetic Loops
• Dynamics of the solar magnetic bright points derived from their horizontal motions
• Relationships between magnetic foot points and G-band bright structures
• Magnetic bright points in the quiet Sun
• The Velocity Distribution of Solar Photospheric Magnetic Bright Points
• Paradoxical diffusion: Discriminating between normal and anomalous random walks
• Migration of Ca II H bright points in the internetwork
• Decay of a simulated mixed-polarity magnetic field in the solar surface layers
• Magnetic field strength distribution of magnetic bright points inferred from filtergrams and spectro-polarimetric data
• Diffusion of magnetic elements in a supergranular cell
• Dynamic properties of bright points in an active region
• First evidence of interaction between longitudinal and transverse waves in solar magnetic elements
• A Subpixel Registration Algorithm for Low PSNR Images
• Spatio-Temporal Scaling of Solar Surface Flows
• The spectrum of kink-like oscillations of solar photospheric magnetic elements
• Thermal relaxation of very small solar magnetic structures in intergranules: a process that produces kG magnetic field strengths

Cited by in corpus (9)

• Observational Evidence of Magnetic Reconnection for Brightenings and Transition Region Arcades in IRIS observations
• Investigation of intergranular bright points from the New Vacuum Solar Telescope
• Kinematics of Magnetic Bright Features in the Solar Photosphere
• On the relationship between G-band bright point dynamics and their magnetic field strengths
• Analysis of quiet-sun turbulence on the basis of SDO/HMI and Goode Solar Telescope data
• Transport of internetwork magnetic flux elements in the solar photosphere
• Dispersion of the solar magnetic flux in undisturbed photosphere as derived from SDO/HMI data
• Dispersion of small magnetic elements inside active regions on the Sun
• Observational characterisation of large-scale transport and horizontal turbulent diffusivity in the quiet Sun