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We report new constraints on the local escape speed of our Galaxy. Our analysis is based on a sample of high velocity stars from the RAVE survey and two previously published datasets. We use cosmological simulations of disk galaxy formation to motivate our assumptions on the shape of the velocity distribution, allowing for a significantly more precise measurement of the escape velocity compared to previous studies. We find that the escape velocity lies within the range $498kms < ve < 608 kms$ (90 per cent confidence), with a median likelihood of $544kms$. The fact that $ve^2$ is significantly greater than $2vc^2$ (where $vc=220kms$ is the local circular velocity) implies that there must be a significant amount of mass exterior to the Solar circle, i.e. this convincingly demonstrates the presence of a dark halo in the Galaxy. For a simple isothermal halo, one can calculate that the minimum radial extent is $sim58$ kpc. We use our constraints on $ve$ to determine the mass of the Milky Way halo for three halo profiles. For example, an adiabatically contracted NFW halo model results in a virial mass of $1.42^{+1.14}_{-0.54}times10^{12}M_odot$ and virial radius of $305^{+66}_{-45}$ kpc (90 per cent confidence). For this model the circular velocity at the virial radius is $142^{+31}_{-21}kms$. Although our halo masses are model dependent, we find that they are in good agreement with each other.
We construct new estimates on the Galactic escape speed at various Galactocentric radii using the latest data release of the Radial Velocity Experiment (RAVE DR4). Compared to previous studies we have a database larger by a factor of 10 as well as re
We model the fastest moving (v_tot > 300 km/s) local (D < 3 kpc) halo stars using cosmological simulations and 6-dimensional Gaia data. Our approach is to use our knowledge of the assembly history and phase-space distribution of halo stars to constra
Direct detection (DD) of dark matter (DM) candidates in the $lesssim$10 GeV mass range is very sensitive to the tail of their velocity distribution. The important quantity is the maximum WIMP speed in the observers rest frame, i.e. in average the sum
We use the kinematics of $sim200,000$ giant stars that lie within $sim 1.5$ kpc of the plane to measure the vertical profile of mass density near the Sun. We find that the dark mass contained within the isodensity surface of the dark halo that passes
We characterize the selection function of RAVE using 2MASS as our underlying population, which we assume represents all stars which could have potentially been observed. We evaluate the completeness fraction as a function of position, magnitude, and