Abstract
The properties of Ellerman bombs (EBs), small-scale brightenings in the
Hα line wings, have proved difficult to establish because their
size is close to the spatial resolution of even the most advanced
telescopes. Here, we aim to infer the size and lifetime of EBs using
high-resolution data of an emerging active region collected using the
Interferometric BIdimensional Spectrometer (IBIS) and Rapid Oscillations
of the Solar Atmosphere (ROSA) instruments as well as the Helioseismic
and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO).
We develop an algorithm to track EBs through their evolution, finding
that EBs can often be much smaller (around 0.3″) and shorter-lived
(less than one minute) than previous estimates. A correlation between
G-band magnetic bright points and EBs is also found. Combining SDO/HMI
and G-band data gives a good proxy of the polarity for the vertical
magnetic field. It is found that EBs often occur both over regions of
opposite polarity flux and strong unipolar fields, possibly hinting at
magnetic reconnection as a driver of these events.The energetics of EB
events is found to follow a power-law distribution in the range of a
nanoflare (1022-25 ergs).
Original language | English |
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Pages (from-to) | 307-323 |
Journal | Solar Physics |
Volume | 283 |
Publication status | Published - 01 Apr 2013 |
Keywords
- Active regions
- Magnetic fields
- Photosphere-sunspots
- Penumbra