EGU22-1253, updated on 27 Mar 2022
https://doi.org/10.5194/egusphere-egu22-1253
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Imaging of the Quiet Sun in the Frequency Range of 20-80MHz

Peijin Zhang1,2,3, Pietro Zucca2, Kamen Kozarev1, Chuanbing Wang4, and Lofar ssw ksp Team2
Peijin Zhang et al.
  • 1Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, Sofia 1784, Bulgaria (peijin@nao-rozhen.org)
  • 2ASTRON, The Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
  • 3Astronomy & Astrophysics Section, Dublin Institute for Advanced Studies, Dublin, Ireland.
  • 4University of Science and Technology of China, School of Earth and Space Science, CAS Key Laboratory of Geospace Environment, Anhui, China (cbwang@ustc.edu.cn)

Radio emission of the quiet Sun is generally believed to be generated from thermal bremsstrahlung emission of the hot solar atmosphere. The imaging properties of the quiet Sun in the microwave band have been well studied, and they fit well to the spectrum of bremsstrahlung emission. In the meter-wave and decameter-wave bands, imaging properties of the quiet Sun have rarely been studied due to the instrumental limitations. In this work, we use the LOw Frequency ARray (LOFAR) telescope to perform high-quality interferometric imaging spectroscopy observations of quiet Sun coronal emission at frequencies below 90~MHz. In these observations of the coronal emission, we achieved unprecedented imaging quality, spatial structures are well resolved. For the first time, we find dark regions with low brightness temperatures. The brightness temperature spectrum of the quiet Sun is obtained and compared with the bremsstrahlung emission of the corona model. 

How to cite: Zhang, P., Zucca, P., Kozarev, K., Wang, C., and Team, L. S. K.: Imaging of the Quiet Sun in the Frequency Range of 20-80MHz, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1253, https://doi.org/10.5194/egusphere-egu22-1253, 2022.

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