Solar Wind Density and Core Temperature Derived from the PSP Quasi-thermal Noise Measurements

Zheng, Xianming;Liu, Kaijun;Martinović, Mihailo M.;Pierrard, Viviane;Wang, Yan;et.al.
(2024) The Astrophysical Journal — Vol. 963, n° 2, p. 154 (2024)

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Authors
  • Zheng, Xianmingorcid-logoDepartment of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, Peopleʼs Republic of China
    Author
  • Liu, Kaijunorcid-logoDepartment of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, Peopleʼs Republic of China
    Author
  • Martinović, Mihailo M.orcid-logoLunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
    Author
  • Pierrard, Vivianeorcid-logoUCLouvain
    Author
  • Wang, Yanorcid-logoDepartment of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, Peopleʼs Republic of China
    Author
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Abstract
Quasi-thermal noise (QTN) spectroscopy is a valuable method to deduce important parameters in space plasma, such as plasma density and temperature, especially when direct particle measurements are not available. The present study develops a new fitting method to fit the QTN spectra observed by the Parker Solar Probe (PSP) with a comprehensive theoretical QTN spectral model. By combining the steepest descent and Levenberg–Marquardt algorithms, the new method is more flexible with initial guess values but still yields reliable solar wind electron density and temperature values. The new method is applied to derive the solar wind density and core temperature from the QTN measurements during 10 encounters of PSP. The electron density and temperature values obtained vary with the radial distance from the Sun as ne ∝ r −2.12 and Te ∝ r −0.71, both of which are consistent with existing models and previous results.
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Citations

Zheng, X., Liu, K., Martinović, M. M., Pierrard, V., Liu, M., He, Q., Cheng, K., Liu, Y., & Wang, Y. (2024). Solar Wind Density and Core Temperature Derived from the PSP Quasi-thermal Noise Measurements. The Astrophysical Journal, 963(2), 154. https://doi.org/10.3847/1538-4357/ad236d (Original work published 2024)