Abstract Details


Name: Aakash Gupta
Affiliation: Physical Research Laboratory
Conference ID: TVS202510183
Title: Quiet-time suprathermal ions in the heliosphere measured by ASPEX-STEPS on-board Aditya-L1
Authors and Co-Authors: Dibyendu Chakrabarty, Santosh Vadawale, Bijoy Dalal, Shiv Kumar Goyal, Jacob Sebastian, M. Shanmugam
Abstract Type: Contributory Presentation
Abstract: The heliosphere is continuously permeated by the solar wind and a broad spectrum of energetic particles. Among them, suprathermal ions represent a key population whose origin, energization, and directional behaviour remain poorly understood. These ions are particularly important because they constitute the seed population for solar energetic particles (SEPs), which can adversely impact satellites, communication systems, and other space-based technologies. In this study, we examine the directional energy spectra of suprathermal ions during quiet solar wind intervals from January to November 2024. The measurements are taken from the Supra-Thermal and Energetic Particle Spectrometer (STEPS), part of the Aditya Solar Wind Particle Experiment (ASPEX) suite on-board India’s Aditya-L1 mission. We utilize four of the six STEPS detectors—Parker Spiral (PS), Inter-Mediate (IM), Earth Pointing (EP), and North Pointing (NP)—with three located in the ecliptic plane and one (NP) oriented orthogonal to it. Spectral slopes derived from these detectors reveal nearly isotropic suprathermal ion distributions, thereby validating the isotropy assumption commonly employed in solving the Parker transport equation. Since STEPS does not provide species separation, we further analyzed elemental abundance ratios using data from the Ultra-Low Energy Isotope Spectrometer (ULEIS) aboard ACE for the same intervals. These results suggest that the quiet-time suprathermal pool largely consists of residual particles from both impulsive solar flares and gradual CME-driven SEP events. Overall, our findings provide new insights into the isotropy and compositional characteristics of suprathermal ions, advancing the understanding of seed particle reservoirs in the heliosphere under quiet solar wind conditions during the maximum phase of Solar Cycle 25.