We use the adiabatic compression theory to build a physically well - motivated Milky Way mass model in agreement with the observational data .
The visible mass of the Galaxy is distributed in a spheroidal bulge and a multi - components disc parametrized by three galactic parameters , the Sun distance to the galactic centre , R _ { 0 } , the total bulge mass , M _ { \mathrm { bulge } } , and the local disc surface density , \Sigma _ { \odot } .
To model the dark matter component , we adiabatically compress a Navarro , Frenk and White ( NFW ) halo ( with concentration c and total mass M _ { \mathrm { vir } } ) for fixed values of the spin parameter , \lambda , the fraction of the mass in baryons , m _ { \mathrm { b } } , and the thin disc contribution to total angular momentum , j _ { \mathrm { d } } .
An iterative selection procedure is used to explore in very detail the wide space of parameters only selecting those combinations of \left \ { R _ { 0 } ,M _ { \mathrm { bulge } } , \Sigma _ { \odot } , \lambda,m _ { \mathrm { b } } ,j _ { % \mathrm { d } } ,c,M _ { \mathrm { vir } } \right \ } that give rise to a Milky Way model in agreement with the observational constraints .
This analysis leads us to conclude that only models with R _ { 0 } = 8.5 kpc , 0.8 { \times } 10 ^ { 10 } M _ { \odot } < M _ { \mathrm { bulge } } < 1.6 { \times } 10 ^ { 10 } M _ { \odot } and 49 M _ { \odot } pc ^ { -2 } \leq \Sigma _ { \odot } \leq 56 M _ { \odot } pc ^ { -2 } can be reconciled with the set of observational constraints .
As regard the parameters entering the adiabatic compression , we find 0.03 \leq \lambda \leq 0.10 and 0.04 \leq m _ { \mathrm { b } } \leq 0.10 , while the final estimates of the parameters describing the initial halo profile turn out to be 5 \stackrel { < } { \sim } c \stackrel { < } { \sim } 12 and 7 { \times } 10 ^ { 11 } M _ { \odot } \stackrel { < } { \sim } M _ { \mathrm { vir } } \stackrel { < } { \sim% } 17 { \times } 10 ^ { 11 } M _ { \odot } ( all at 95.7 \% CL ) .