Résumé / Abstract Journal-club_Galaxies

Séminaire/Seminar Galaxies

« Detection of the Keplerian decline in the Milky Way rotation curve »

Yongjun Jiao
Dept. Galaxies, Etoiles, Physique et Instrumentation (GEPI), Obs. Paris-Meudon-Nancay (Meudon, France)

The rotation curve (RC) is the most accurate tool for estimating the enclosed dynamical mass of the galaxy. Utilizing the comprehensive data from Gaia Data Release 3 (DR3), we have established a precise Milky Way (MW) RC up to 26.5 kpc with a robust analysis of the systematic uncertainties. We find a sharply decreasing RC for the MW, the decrease in velocity between 19.5 and 26.5 kpc is approximately 30 km/s. With this RC, we estimate the MW total mass is 2.06 10^11 Msun. By studying the decrease in RC at large radii, we identify a Keplerian decline in the RC between 19 and 26 kpc from the MW centre, while a flat RC is rejected with a significance of 3 sigma. In this presentation, I will present our analysis of systematic uncertainties based on the previous measurement of MW RC, the estimation of MW total mass and discuss the detection of the Keplerian decline in the MW RC.
jeudi 12 octobre 2023 - 11:30
Salle 281
Institut d'Astrophysique de Paris
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