AX J1745.6-2901 is an X-ray binary located at only 1.45 arcmin from Sgr A ^ { \star } , showcasing a strong X-ray dust scattering halo .
We combine Chandra and XMM-Newton observations to study the halo around this X-ray binary .
Our study shows two major thick dust layers along the line of sight ( LOS ) towards AX J1745.6-2901 .
The LOS position and N _ { H } of these two layers depend on the dust grain models with different grain size distribution and abundances .
But for all the 19 dust grain models considered , dust Layer-1 is consistently found to be within a fractional distance of 0.11 ( mean value : 0.05 ) to AX J1745.6-2901 and contains only ( 19-34 ) % ( mean value : 26 % ) of the total LOS dust .
The remaining dust is contained in Layer-2 , which is distributed from the Earth up to a mean fractional distance of 0.64 .
A significant separation between the two layers is found for all the dust grain models , with a mean fractional distance of 0.31 .
Besides , an extended wing component is discovered in the halo , which implies a higher fraction of dust grains with typical sizes \lesssim 590 Å than considered in current dust grain models .
Assuming AX J1745.6-2901 is 8 kpc away , dust Layer-2 would be located in the Galactic disk several kpc away from the Galactic Centre ( GC ) .
The dust scattering halo biases the observed spectrum of AX J1745.6-2901 severely in both spectral shape and flux , and also introduces a strong dependence on the size of the instrumental point spread function and the source extraction region .
We build Xspec models to account for this spectral bias , which allow us to recover the intrinsic spectrum of AX J1745.6-2901 free from dust scattering opacity .
If dust Layer-2 also intervenes along the LOS to Sgr A ^ { \star } and other nearby GC sources , a significant spectral correction for the dust scattering opacity would be necessary for all these GC sources .