Stellar populations and large-scale structure of the SMC – II. Geometry of the north-eastern and south-western outlying regions

The three-dimensional (3D) distribution of the old disc and halo populations in the Small Magellanic Cloud (SMC) outlying (projected distances from the optical centre larger than 2 kpc) north-eastern and south-western regions is presented. The magnitudes of the Horizontal Branch (HB)/clump stars in these regions are used as distance indicators. It is shown that in the north-eastern regions there is a significant line-of-sight depth of 17 kpc on average, reaching a maximum value of 23 kpc. These regions are ∼ 10 kpc deeper than the south-western regions. This result is attributed to the disruptive effect of the tidal field of the Large Magellanic Cloud (LMC) on the SMC. The possibility of the existence of two separate entities along the line-of-sight is examined.