Small-Scale Structuring Of Ellerman Bombs at Solar Limb

Abstract

Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disc. In this article, we make use of high-resolution, high-cadence observations of an AR at the solar limb, collected by the CRISP instrument, to identify EBs and infer their physical properties. The upper atmosphere is also probed using the SDO/AIA. We analyse 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s^(-1), extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical `flaring' (changing in area and intensity) observed in on-disc events. Two in-depth case studies are also presented which highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the H-alpha line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the H-alpha line core, and are not observed by the SDO/AIA EUV filters.

10 pages, 7 figures, accepted to ApJ

References in corpus (6)

• CRISP Spectropolarimetric Imaging of Penumbral Fine Structure
• 3D Temperature Mapping of Solar Photospheric Fine Structure Using Ca II H Filtergrams
• Statistical properties of the Disk Counterparts of Type II Spicules from simultaneous observations of RBEs in Ca II 8542 and Hα
• Stokes diagnostics of simulated solar magneto-convection
• Statistical Analysis of Small Ellerman Bomb Events
• HINODE Observations of Chromospheric Brightenings in the Ca II H Line during small-scale Flux Emergence Events

Cited by in corpus (10)

• Heating mechanisms in the low solar atmosphere through magnetic reconnection in current sheets
• Magnetic reconnection in strongly magnetized regions of the low solar chromosphere
• IRIS Burst Spectra Co-Spatial To A Quiet-Sun Ellerman-Like Brightening
• Flame-like Ellerman Bombs and Their Connection to Solar UV Bursts
• On The Relationship Between Magnetic Cancellation and UV Burst Formation
• Ellerman Bombs with Jets: Cause and Effect
• Multi-wavelength Spectral Analysis of Ellerman Bombs Observed by FISS and IRIS
• Solar Ellerman Bombs in 1-D Radiative Hydrodynamics
• RADYN simulations of non-thermal and thermal models of Ellerman bombs
• Automating Ellerman bomb detection in ultraviolet continua