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)