C45

Presentation Title: Nanojets as pointers to the flare energy release process
Author(s): Ramada Sukarmadji, Patrick Antolin, James McLaughlin, Stephane Regnier

Abstract:

The discovery of nanojets by Antolin et al. (2021) represents magnetic reconnection in a braided field, thus clearly identifying the reconnection-driven nanoflares from similar intensity bursts produced by other mechanisms. Nanojets have since been found in multiple coronal structures, namely in a coronal loop powered by a blowout jet and in coronal loops with coronal rain (Sukarmadji et al. 2022). In these cases, the reconnection at their origin is due to dynamic instabilities (Kelvin-Helmholtz or Rayleigh-Taylor) in a braided field. The variety of structures and environments where they are found support nanojets as a general result of small-angle component reconnection. However, it is still unclear how pervasive nanojets are in the solar corona and whether they play a role in heating within large-scale heating events such as flares. In this talk, we present IRIS and SDO observations of nanojets found in a C-class flare. In agreement with previous findings, we observe that nanojets are accompanied by small nanoflare-like intensity bursts in the (E)UV, have fast velocities over ~150 km s^{-1}, and occur transversely to the field line of origin. However, the number of nanojets found in this flare event greatly exceeds the previous cases, and the nanojets have larger energy releases up to the microflare range individually, both suggesting a correlation with the energy release of the event. The occurrence of the nanojets also coincides with the timing of the peaks in the GOES X-rays derivative, meaning that the heating signatures from the nanojets may be identifiable in the GOES X-rays. Such small and short-lived energy releases from nanojets that can only be detected with high-resolution observations indicate that there may still be many unresolved small-scale reconnection events that can potentially contribute significantly to the heating of the structure.