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Can the temperature of Ellerman Bombs be more than 10 000 K?

Cheng Fang, Qi Hao, Ming-De Ding, Zhen Li

Abstract


Ellerman bombs (EBs) are small brightening events in the solar lower atmosphere. By their original definition, the main characteristic of EBs is the two emission bumps in both wings of chromospheric lines, such as Hα and Ca II 8542 Å lines. Up to now, most authors have found that the temperature increase of EBs around the temperature minimum region is in the range of 600–3000 K. However, with recent IRIS observations, some authors proposed that the temperature increase of Ebs could be more than 10 000 K. Using non-LTE semi-empirical modeling, we investigate the line profiles, continuum emission and radiative losses for EB models with different temperature increases, and compare them with observations. Our result indicates that if the EB maximum temperature reaches more than 10 000 K around the temperature minimum region, then the resulting Hα and Ca II 8542 Å line profiles and the continuum emission would be much stronger than those of EB observations. Moreover, due to the high radiative losses, a high temperature EB would have a very short lifetime, which is not compatible with observations. Thus, our study does not support the proposal that EB temperatures are higher than 10 000 K.


Keywords


line profiles — Sun: photosphere — Sun: chromosphere

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DOI: http://dx.doi.org/10.1088/1674%E2%80%934527%2F17%2F4%2F31

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Print ISSN: 1674-4527

Online ISSN: 2397-6209