Seminářové odpoledne a přednáška: Spectroscopy and modeling of Ellerman bursts

Astronomický ústav pořádá v úterý 28. června 2016 od 13 hodin seminářové odpoledne. V rámci této akce proběhne přednáška o Ellermanových bombách, kterou povede Arek Berlicki (University of Wroclaw).

Spectroscopy and modeling of Ellerman bursts

Abstrakt:

Observations of Ellerman bursts (EBs) show them as a small brightenings well observed in different chromospheric lines, both in the optical and UV spectral ranges (H I, Ca II, Mg II). EBs are manifestation of small reconnection processes occurred in the lower solar atmosphere and they can contribute to the chromospheric heating. H-alpha line profiles of EBs exhibit enhanced emission at line-wings even up to a few angstroms from the line core. On the contrary, Ca II and Mg II lines emitted by EBs can be strongly enhanced also in the line cores. We used new UV (IRIS) spectroscopic observations to find models of different EBs observed in the new magnetic flux emergence area. Obtained models of EBs showed that they can be described by one or two component 'hot-spot’ thermal structure.  We found that EBs can be formed in an extended domain of altitudes in the photosphere and/or the chromosphere (400 to 750 km). Our results are consistent with the theory of heating by Joule dissipation in the atmosphere produced by magnetic field reconnection during flux emergence. I will also discuss the new EBs diagnostics possibilities based on the new radio observations in millimeter range obtained in future by ALMA instrument.
 

Další přednášky seminářového odpoledne:

• Long-term activity of soft X-ray transients - přednáší: Vojtěch Šimon
• New regime of fragmentation of gaseous layers - přednáší: František Dinnbier
• Stubenberg meteorite fall - demonstration of capabilities of the Czech fireball network - přednáší Pavel Spurný

Přednášky jsou v anglickém jazyce.

Abstrakty přednášek a další informace najdete zde.