  Analyses of recent cosmic microwave background (CMB) observations have
provided increasing indications for the existence of large scale anisotropy in
the universe. Given the far reaching consequences of such an anisotropy for our
understanding of the universe, it is important to employ alternative indicators
in order to determine whether the reported anisotropy is cosmological in
origin, and if so extract further information that may be helpful for
identifying its causes. Here we propose a new directional indicator, based on
angular-separation histograms of pairs of pixels with similar temperatures in
the CMB map, which provides a measure of departure from statistical isotropy.
The main advantage of this indicator is that it can be used to generate a sky
map of large-scale anisotropies in the CMB temperature map, thus allowing a
possible additional window into their causes. Using this indicator, we find a
statistically significant (at 95% CL) preferred direction in the CMB data and
discuss how it compares with other such axes recently reported. We also show
that our findings are robust with respect to both the details of the method
used, and the choice of the WMAP CMB maps employed, including the three-year
CMB data released recently.
