Hydrodynamics of small transient brightenings in Solar corona

TL;DR

This study models small transient brightenings in the solar corona using hydrodynamical simulations, showing they share physical characteristics with larger flares and may have a common origin.

Contribution

The paper introduces a hydrodynamical modeling approach for small coronal transients, demonstrating their similarity to larger flare phenomena and suggesting a shared physical origin.

Findings

Simulated light curves agree with observations

Conduction flux dominates initially, like flares

Net enthalpy flux is positive, entering the corona

Abstract

Small scale transients occur in the Solar corona at much higher frequencies than flares and play a significant role in coronal dynamics. Here we study three well-identified transients discovered by Hi-C and also detected by the EUV channels of Atmospheric Imaging Assembly (AIA) on board Solar Dynamics Observatory (SDO). We use 0-D enthalpy-based hydrodynamical simulations and produce synthetic light curves to compare with AIA observations. We have modeled these transients as loops of ~ 1.0~Mm length depositing energies ~ 10^23 ergs in ~ 50 seconds. The simulated synthetic light curves show reasonable agreement with the observed light curves. During the initial phase, conduction flux from the corona dominates over the radiation, like impulsive flaring events. Our results further show that the time-integrated net enthalpy flux is positive, hence into the corona. The fact that we can model the observed light curves of these transients reasonably well by using the same physics as those for nanoflares, microflares, and large flares, suggests that these transients may have a common origin.