On the local dark matter density

Moni Bidin et al. (2012, ApJ, 751, 30, hereafter MB12) has recently proposed a new formulation to calculate the dynamical mass density enclosed in a large volume of the Galaxy, by means of the three-dimensional kinematics of a test stellar population. Applying this formulation to three kinematical data sets available in the literature, they surprisingly found a lack of dark matter at the Solar position. Bovy & Tremaine (2012, ApJ, 756, 89, hereafter BT12) argued that MB12 calculation is flawed by a wrong assumption, and that a corrected one-dimensional formulation recovers the expected amount of dark matter. In this contribution, we show that BT12 formulation is based on an assumption ruled out by all observational evidence, that causes a strong overestimate of the mass density. Moreover, we show that the MB12 assumption criticized by BT12 has negligible effects on the results, hence their criticisms is not the solution to the puzzling results found by MB12.