We present a detailed study of the X-ray dust scattering halo of the black hole candidate Cygnus X-1 based on two Chandra HETGS observations .
Using 18 different dust models , including one modified by us ( dubbed XLNW ) , we probe the interstellar medium between us and this source .
A consistent description of the cloud properties along the line of sight that describes at the same time the halo radial profile , the halo lightcurves , and the column density from source spectroscopy is best achieved with a small subset of these models .
Combining the studies of the halo radial profile and the halo lightcurves , we favor a geometric distance to Cygnus X-1 of d = 1.81 \pm { 0.09 } kpc .
Our study also shows that there is a dense cloud , which contributes \sim 50 % of the dust grains along the line of sight to Cygnus X-1 , located at \sim 1.6 kpc from us .
The remainder of the dust along the line of sight is close to the black hole binary .