The escape speed curve of the Galaxy obtained from Gaia DR2 implies a heavy Milky Way

We measure the escape speed curve of the Milky Way based on the analysis of the velocity distribution of similar to 2850 counter-rotating halo stars from the Gaia Data Release 2. The distances were estimated through the StarHorse code, and only stars with distance errors smaller than 10% were used in the study. The escape speed curve is measured at Galactocentric radii ranging from similar to 5 kpc to similar to 10.5 kpc. The local Galactic escape at the Sun's position is estimated to be v(e)(r(circle dot)) = 580 +/- 63 km s(-1), and it rises towards the Galactic centre. Defined as the minimum speed required to reach three virial radii, our estimate of the escape speed as a function of radius implies for a Navarro-Frenk-White profile and local circular velocity of 240 km s(-1) a dark matter mass M-200 = 1.28(-0.50) (+0.68) x 10(12) M-circle dot and a high concentration c(200) = 11.09(-1.79)(+2.94). Assuming the mass-concentration relation of ACDM, we obtain M-200 = 1.55(-0.51)(+0.64) x 10(12) M-circle dot and c(200) = 7.93(-0.27)(+0.33)for a local circular velocity of 228 km s(-1).