English

Signatures of dynamic fibrils at the coronal base: Observations from Solar Orbiter/EUI

Solar and Stellar Astrophysics 2023-02-01 v1

Abstract

The solar chromosphere hosts a wide variety of transients, including dynamic fibrils (DFs) that are characterised as elongated, jet-like features seen in active regions, often through Hα\alpha diagnostics. So far, these features have been difficult to identify in coronal images primarily due to their small size and the lower spatial resolution of the current EUV imagers. Here we present the first unambiguous signatures of DFs in coronal EUV data using high-resolution images from the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter. Using the data acquired with the 174~{\AA} High Resolution Imager (HRIEUV_{EUV}) of EUI, we find many bright dot-like features (of size 0.3-0.5 Mm) that move up and down (often repeatedly) in the core of an active region. In a space-time map, these features produce parabolic tracks akin to the chromospheric observations of DFs. Properties such as their speeds (14 km~s1^{-1}), lifetime (332~s), deceleration (82 m~s2^{-2}) and lengths (1293~km) are also reminiscent of the chromospheric DFs. The EUI data strongly suggest that these EUV bright dots are basically the hot tips (of the cooler chromospheric DFs) that could not be identified unambiguously before because of a lack of spatial resolution.

Keywords

Cite

@article{arxiv.2212.05025,
  title  = {Signatures of dynamic fibrils at the coronal base: Observations from Solar Orbiter/EUI},
  author = {Sudip Mandal and Hardi Peter and Lakshmi Pradeep Chitta and Regina A. Cuadrado and Udo Schühle and Luca Teriaca and Sami K. Solanki and Louise Harra and David Berghmans and Frédéric Auchère and Susanna Parenti and Andrei N. Zhukov and Éric Buchlin and Cis Verbeeck and Emil Kraaikamp and Luciano Rodriguez and David M. Long and Conrad Schwanitz and Krzysztof Barczynski and Gabriel Pelouze and Philip J. Smith and Wei Liu and Mark C. Cheung},
  journal= {arXiv preprint arXiv:2212.05025},
  year   = {2023}
}

Comments

Accepted for publication in A&A Letters. Event movie can be downloaded from https://drive.google.com/file/d/1o_4jHA5JbyQtrpUBtB3ItE_s3HjF6ncc/view?usp=sharing