22–27 Sept 2025
INAF, Osservatorio Astronomico di Roma
Europe/Rome timezone

Conditions for Solar Prominence Formation Triggered by Single Localized Heating

23 Sept 2025, 11:30
15m
Aula Gratton (INAF, Osservatorio Astronomico di Roma)

Aula Gratton

INAF, Osservatorio Astronomico di Roma

Via Frascati, 33, 00078 Monteporzio Catone (RM)
Contributed Talk

Speaker

Takero Yoshihisa (Kyoto University, Japan)

Description

We performed numerical simulations to study mechanisms of solar prominence formation triggered by a single heating event. In the widely accepted “chromospheric-evaporation condensation” model, localized heating at footpoints of a coronal loop drives plasma evaporation and eventually triggers condensation through the development of thermal instability. The occurrence of condensation is strongly influenced by the characteristics of the heating. Various theoretical studies have been conducted along one-dimensional field lines with quasi-steady localized heating. The quasi-steady heating is regarded as the collection of multiple heating events among multiple strands constituting a coronal loop. However, it is reasonable to consider a single heating event along a single strand as an elemental unit to investigate the onset of thermal instability in isolation.
We investigated the condensation phenomenon triggered by a single heating event using 1.5-dimensional magnetohydrodynamic simulations. By varying the magnitude of the manually imposed localized heating rate, we explored the conditions necessary for condensation. We found that, when a heating rate approximately $\sim 10^{4}$ times greater than that of steady heating was applied, condensation occurred. Condensation was observed when the thermal conduction efficiency in the loop became lower than the cooling efficiency, with the cooling rate significantly exceeding the heating rate. Using the loop length L and the Field length $\lambda_{F}$, the condition for condensation is expressed as $\lambda_{F}

Sessions Instabilities

Author

Takero Yoshihisa (Kyoto University, Japan)

Co-authors

Prof. Takaaki Yokoyama (Kyoto Univ.) Dr Takafumi Kaneko (Niigata Univ.)

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