Speaker
Tine Libbrecht
(Institute for Solar Physics, Stockholm University)
Description
Ellerman Bombs (EBs) are short-lived emission features observed in the wings of
Balmer lines of hydrogen. So far, no distinct signature of EBs has been found in the
He I λ10830 line, and observations of EBs in He I D3 have never been reported. We aim
to study the signature of EBs in neutral helium triplet lines using SST/TRIPPEL
raster scans, featuring the Hβ, He I D3 and He I λ10830 spectral regions. We also
obtained raster scans with IRIS and make use of the SDO/AIA 1700 Å channel. Three of
the EBs in our data show distinct emission signatures in He I D3. In some cases,
there are some weaker emission effects in He I λ10830 as well. The helium lines seem
to have two components: a broadened and blueshifted emission component, probably
associated with the EB, and an absorption component, probably due to absorption in
the overlying chromosphere. With HeLiX+, we disentangle the two components in the
spectra. Recently, there has been a discussion on the nature of IRIS bombs and
Ellerman Bombs observed in the Si IV 1400 Å spectral lines with IRIS. It has been
suggested that Ellerman Bombs are possibly much hotter than previously thought. We
indeed believe that very high temperatures are needed to create EB emission
signatures in neutral helium triplet lines.
Primary author
Tine Libbrecht
(Institute for Solar Physics, Stockholm University)
