Figure 2. Heliocentric distances (upper panel) and longitudes (lower panel) of the source are deduced from observations of four spacecraft (obs) and simulations (sim) of radio wave proliferation for anisotropic scattering impacts. Adapted from Chen et al, A&A 2023
The source positions at each frequency acquired from observations and simulations are displayed in Figure 1 and Figure 2. From observations, the radio sources longitudes deduced from the intensity fit are equivalent to the longitudes from the direction-finding measurement and the radio sources follow a rather straightforward trajectory. The radio source is found to be situated even more away with a decreasing frequency however did not follow a specific direction through timing technique. The radial ranges deduced from observations surpass the values forecasted by density models, showing alignment with radio-wave proliferation impacted by anisotropic scattering, which could cause an evident position at a heliocentric range further from the Sun. From radio-wave proliferation simulations, the direction deduced from the intensity fit is close to that of the evident source, which deviates from an angle from the given intrinsic source and seems to be closely lined up with the Parker spiral magnetic field. The heliocentric ranges and longitudes identified from the timing technique do not match the evident sources, recommending that the source positions might be underestimated.
Based on the current paper by Xingyao Chen, Eduard P. Kontar, Nicolina Chrysaphi, Peijin Zhang, Vratislav Krupar, Sophie Musset, Milan Maksimovic, Natasha L. S. Jeffrey, Francesco Azzollini, and Antonio Vecchio, Source positions of an interplanetary type III radio burst and anisotropic radio-wave scattering, A&A 680, A1 (2023 ), DOI: 10.1051/ 0004-6361/2023 47185.
References.
Kontar, E. P., Chen, X., Chrysaphi, N., et al., 2019, ApJ, 884, 122.
Musset, S., Maksimovic, M., Kontar, E., et al., 2021, A&A, 656, A34.
Chen, X., Kontar, E. P., Clarkson, D. L., & & Chrysaphi, N. 2023, MNRAS, 520, 3117.
Kontar, E. P., Emslie, A. G., Clarkson, D. L., et al., 2023 ApJ, 956, 112
Source positions deduced from (a) observations and (b) simulations utilizing both the strength fit and timing method. Adjusted from Chen et al, A&A 2023
From observations, the radio sources longitudes deduced from the strength fit are equivalent to the longitudes from the direction-finding measurement and the radio sources follow a rather straightforward trajectory.
Due to the absence of direct radio source imaging, a number of methods have actually been established to identify the source positions from space-based observations. While the precise identification of the true source position proves challenging through observations, ray-tracing simulations of radio-wave propagation provide an intrinsic source position. By tracking the obvious source positions after radio waves undergo scattering, it becomes engaging to employ both techniques to examine simulated time profiles and compare the deduced source position with the intrinsic and obvious positions.
Interplanetary solar radio type III bursts offer the means to remotely study and track energetic electrons propagating in the interplanetary medium. Due to the absence of direct radio source imaging, a number of methods have actually been developed to identify the source positions from space-based observations. None of the methods think about the proliferation effects of anisotropic radio-wave scattering, which would highly misshape the trajectory of radio waves, delay their arrival times, and affect their apparent qualities (Kontar et al. 2019, 2023, Musset et al. 2021, Chen et al. 2023).
In this research study, we apply the intensity fit and timing techniques to examine the source positions and directivity of an interplanetary type III burst simultaneously observed by Parker Solar Probe, Solar Orbiter, STEREO, and Wind. While the accurate identification of the real source position shows challenging through observations, ray-tracing simulations of radio-wave propagation supply an intrinsic source position. By tracking the apparent source positions after radio waves undergo scattering, it ends up being engaging to employ both methods to examine simulated time profiles and compare the deduced source position with the intrinsic and obvious positions.
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