Table 2
Density laws where ρ0 is the local mass density, d0 a normalization factor to have a density of 1 at the solar position, kflare the flare factor and 
in kpc with ϵ being the axis ratio and (R,z) the cylindrical galactic coordinates. Local density ρ0 and axial ratio ϵ can be found in Table 1.
| Population | Density laws | |
|
|
||
| Thin disc |  with hR + = 5000 pc and hR− = 3000 pc |
if age ≤ 0.15 Gyr |
 with hR + = 2530 pc and hR− = 1320 pc |
if age > 0.15 Gyr | |
|
|
||
| Thick disc |
|
if |z| ≤ xl,xl = 72 pc |
 with hR = 4000 pc and hz = 1200 pc |
if |z| > xl,xl = 72 pc | |
|
|
||
| Spheroid |
|
if a ≤ ac, ac = 500 pc |
|
if a > ac, ac = 500 pc | |
|
|
||
| Bulge |
|
|
 with  |
|
|
Notes. For simplicity the disc density law is given here without the warp and flare (see text for their characteristics). For the bulge, x,y,z are in the bulge reference frame and values of N, x0, y0, z0, Rc as well as angles from the main axis to the Galaxy reference frame are given in Robin et al. (2003, Table 5).
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