Anticorrelation between the Bulk Speed and the Electron Temperature in the Pristine Solar Wind: First Results from the Parker Solar Probe and Comparison with Helios - Maksimovic,M; Bale,SD; Bercic,L; Bonnell,JW; Case,AW; de,Wit TD; Goetz,K; Halekas,JS; Harvey,PR; Issautier,K; Kasper,JC; Korreck,KE; et al. (ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2020)