Explosive events associated with a surge

TL;DR

This study shows that small-scale solar transient events like surges and explosive events are interconnected, often triggered by phenomena such as Elerman bombs, and highlights the ambiguity in classifying these features based solely on limited observational data.

Contribution

It demonstrates the interrelation between surges and explosive events using simultaneous spectral and imaging data, challenging traditional classification methods.

Findings

SUMER line profiles attributed to explosive events are caused by surges.

Surges are likely triggered by Elerman bombs visible in multiple wavelengths.

Classification of small-scale events based solely on spectral or imaging data is often ambiguous.

Abstract

The solar atmosphere contains a wide variety of small-scale transient features. Here, we explore the inter-relation between some of them such as surges, explosive events and blinkers via simultaneous spectral and imaging data taken with the TRACE imager, the SUMER, and CDS spectrometers on board SoHO, and SVST La Palma. The alignment of all data both in time and solar XY shows that SUMER line profiles, which are attributed to explosive events, are due to a surge phenomenon. The surge is triggered, most probably, by one or more Elerman bombs which are best visible in Halpha +-350 A but were also registered by TRACE Fe IX/X 171 A and correspond to a strong radiance increase in the CDS Mg IX 368.07 A line. With the present study we demonstrate that the division of small-scale transient events into a number of different subgroups, for instance explosive events, blinkers, spicules, surges or just brightenings, is ambiguous, implying that the definition of a feature based only on either spectroscopic or imaging characteristics as well as insufficient spectral and spatial resolution can be incomplete.