Origin of the Weak Plasma Emission Line Detected by Voyager 1 in the Interstellar Medium: Evidence for Suprathermal Electrons - Gurnett, DA; Kurth, WS; Burlaga, LF; Berdichevsky, DB; Pogorelov, N; Pulupa, M; Bale, SD (ASTROPHYSICAL JOURNAL, 2021)