OBJECTIVE: To study the behavior of the vector magnetic field and possible changes in thermodynamics parameters of flaring active regions in coordination with our observing run at the Dunn Solar Telescope.
SCIENTIFIC RATIONALE Our knowledge of the vector magnetic field and thermodynamics during the flare activity has recently improved after several results obtained with IBIS and FIRS in coordination with Hinode-SOT/SP (Judge et al., 2010; Kleint, 2012). However, many questions related with ARs that show flare activity need to be answered: i) how is the topology of the sunspot of the AR modified? ii) what is the evolution of the line-of-sight electric density current and the Lorentz force in the AR? iii) how does the magnetic field interact with the plasma in the chromosphere before, during and after the flare event? iv) if there is a modification both in the topology and the evolution of the AR, does the energy release propagate from the photosphere to the chromosphere or vice versa? (see Figure1) and v) what is the role of the reverse Evershed flow in producing flares in some sunspots? (Kleint & Sainz Dalda, 2013, see Figure 2).
--- Figure 1. Left: NOAA AR 11302 observed by IBIS on September 24, 2011. The unusual umbral filaments (marked as 1, 2, and 3) were related with flare activity and chromospheric heating. Right: Brightening in the umbral filaments observed by IBIS in Ca II 8542 A during an M flare. Figures from Kleint & Sainz Dalda (2013) ---
The Sun is at the maximum of its activity, meaning such observations are best done now to capture a sufficient number of flares. Thus, we aim to observe several C- and M-class flares and possibly an X-class flare during our observations. Coordinated observation involving Hinode, IBIS and FIRS are ideally suited to investigate the above questions.
--- Figure 2. NOAA AR 11302 observed by Hinode/SOT-SP at Fe I 6301 & 6302 A. The unusual penumbral filaments host reversed Evershed flow (in blue), both in the more horizontal component of the penumbra (2nd row) and the more vertical component (1st row). Figure from Kleint & Sainz Dalda, (2013) ---
We would like to request coordinated Hinode/IRIS observations during the observing time that we were awarded at the Dunn Solar Telescope (DST) at Sac Peak. Dates: March 22-March 31, 2014. Usual observing time at the DST in UT: 1400-1800.
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