While it is incontrovertible that the inner Galaxy contains a bar , its structure near the Galactic plane has remained uncertain , where extinction from intervening dust is greatest .
We investigate here the Galactic bar outside the bulge , the long bar , using red clump giant ( RCG ) stars from UKIDSS , 2MASS , VVV , and GLIMPSE .
We match and combine these surveys to investigate a wide area in latitude and longitude , |b| \leq 9 ^ { \circ } and |l| \leq 40 ^ { \circ } .
We find : 1 . The bar extends to l \sim 25 ^ { \circ } at |b| \sim 5 ^ { \circ } from the Galactic plane , and to l \sim 30 ^ { \circ } at lower latitudes . 2 . The long bar has an angle to the line-of-sight in the range ( 28 - 33 ) ^ { \circ } , consistent with studies of the bulge at |l| < 10 ^ { \circ } . 3 . The scale-height of RCG stars smoothly transitions from the bulge to the thinner long bar . 4 . There is evidence for two scale heights in the long bar .
We find a \sim 180 { pc } thin bar component reminiscent of the old thin disk near the sun , and a \sim 45 { pc } super-thin bar component which exists predominantly towards the bar end . 5 . Constructing parametric models for the RC magnitude distributions , we find a bar half length of 5.0 \pm 0.2 { kpc } for the 2-component bar , and 4.6 \pm 0.3 { kpc } for the thin bar component alone . We conclude that the Milky Way contains a central box/peanut bulge which is the vertical extension of a longer , flatter bar , similar as seen in both external galaxies and N-body models .