Two-dimensional density profiles of the propagating plasma stream in the yz plane (a, c, e, and g) and the xz plane (b, d, f, and h) at 28 ns (a and b), 38 ns (c and d), 68 ns (e and f), 88 ns (g and h) after the laser irradiation of the target. The spatial scale, shown in (c), is the same for all the images. The colour bar is the same for all the images. The red ellipses on the left edge of the box in panels (g) and (h) represent the characteristic sizes in the yz and xz planes respectively, of the laser beam irradiating the target.