Speaker
Description
Ellerman bombs (EBs) are transient brightenings in the wings of chromospheric lines, recognized as signatures of magnetic reconnection in the lower solar atmosphere. However, the three-dimensional (3D) magnetic topology of EBs has remained elusive due to the lack of seamless height coverage in spectropolarimetric observations.
We present initial results from SUNRISE III/SCIP observations of an emerging flux region obtained on 2024 July 15. SCIP performed simultaneous full-Stokes spectropolarimetry in Fe I 846.8 nm, K I D1/D2 (769.8/766.4 nm), and Ca II infrared triplet lines (849.8/854.2 nm), providing seamless diagnostics from the photosphere to the chromosphere with diffraction-limited spatial resolution. By applying the Weak Field Approximation to the multi-line dataset, we reconstructed three-dimensional line-of-sight magnetic field.
We identify two distinct classes of reconnection events.
In Event 1, the bipolar magnetic structure is confined to the lower layers (K I and Ca II wing heights), while a unipolar field configuration and no significant core intensity enhancement are found in the Ca II 854.2 nm core. These results indicate the low-altitude reconnection and heating.
In Event 2, the bipolar structure persists up to the Ca II 854.2 nm core formation height, accompanied by clear core brightening, indicating that the current sheet extends to higher altitudes and drives chromospheric heating. These contrasting behaviors were predicted by MHD-based synthetic observations (Kawabata et al. 2024, ApJ), and the SCIP observations now provide direct observational confirmation.
These results demonstrate that SCIP has successfully resolved the 3D structure of magnetic reconnection at different atmospheric heights. Future work will employ Non-LTE inversions to derive the thermal structure.