Vasquez S.; Zoccali M.; Hill V.; Renzini A.; Gonzalez O.A.; Gardner E.; Debattista V.P.; Robin A.C.; Rejkuba M.; Baffico M.; Monelli M.; Motta V.; Minniti D.
(2014-04-04)
Context. It has recently been discovered that the Galactic bulge is X-shaped, with the two southern arms of the X both crossing the lines of sight at l = 0 and | b| > 4, hence producing a double red clump in the bulge ...