Effects of flares on solar high-degree helioseismic acoustic mode amplitudes. (arXiv:2102.13181v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Soares_M/0/1/0/all/0/1">M. Cristina Rabello Soares</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baudin_F/0/1/0/all/0/1">Frederic Baudin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Teixeira_V/0/1/0/all/0/1">Vanessa G. Teixeira</a>
Several attempts have been made to observe whether solar flares excite
acoustic modes since Wolff (1972) suggested this possibility. Moreover, the
rapid progress of asteroseismology and the study of stellar flares makes the
study of these phenomena in the Sun important to inform our study of the
influence of the more energetic stellar flares on asteroseismic acoustic modes.
We look for the impact of flares on the amplitude of solar acoustic modes and
other effects that are also affecting the mode amplitude. Solar acoustic mode
amplitudes are known to be sensitive to magnetic fields. As flares usually
occur in the presence of strong magnetic fields and most likely are the
by-product of magnetic reconnection, we show how the magnetic field in and
around the flaring region affects the mode amplitude. The mode amplitudes were
obtained using ring-diagram analysis, which was first applied to a single
event, the largest flare in the space age (the `Halloween Flare’,
SOL2003-10-28T11:00), using MDI data. Then, using HMI data, the analysis was
applied to the regions corresponding to the flares observed during the high
activity phase of cycle 24 and that fall into two groups. These two groups
consist of small (10-60 erg cm$^{-2}$ s$^{-1}$) and large ($>$1200 erg
cm$^{-2}$ s$^{-1}$) peak-flux flares, based on the Heliophysics Event
Knowledgebase (HEK).
After applying several corrections in order to take into account several
sources of bias, we did not find any amplification in the inferred mode
amplitude due to flaring activity, within a 10% uncertainty.
Several attempts have been made to observe whether solar flares excite
acoustic modes since Wolff (1972) suggested this possibility. Moreover, the
rapid progress of asteroseismology and the study of stellar flares makes the
study of these phenomena in the Sun important to inform our study of the
influence of the more energetic stellar flares on asteroseismic acoustic modes.
We look for the impact of flares on the amplitude of solar acoustic modes and
other effects that are also affecting the mode amplitude. Solar acoustic mode
amplitudes are known to be sensitive to magnetic fields. As flares usually
occur in the presence of strong magnetic fields and most likely are the
by-product of magnetic reconnection, we show how the magnetic field in and
around the flaring region affects the mode amplitude. The mode amplitudes were
obtained using ring-diagram analysis, which was first applied to a single
event, the largest flare in the space age (the `Halloween Flare’,
SOL2003-10-28T11:00), using MDI data. Then, using HMI data, the analysis was
applied to the regions corresponding to the flares observed during the high
activity phase of cycle 24 and that fall into two groups. These two groups
consist of small (10-60 erg cm$^{-2}$ s$^{-1}$) and large ($>$1200 erg
cm$^{-2}$ s$^{-1}$) peak-flux flares, based on the Heliophysics Event
Knowledgebase (HEK).
After applying several corrections in order to take into account several
sources of bias, we did not find any amplification in the inferred mode
amplitude due to flaring activity, within a 10% uncertainty.
http://arxiv.org/icons/sfx.gif
