The structure of the Galactic bar

Abstract

We present a deep near-infrared wide-angle photometric analysis of the structure of the inner Galactic bar and central disc. The presence of a triaxial structure at the centre of the Galaxy is confirmed, consistent with a bar inclined at 22° ± 5°.5 from the Sun - Galactic Centre line, extending to approximately 2.5 kpc from the Galactic Centre and with a rather small axis ratio. A feature at l = -9°.8 not aligned with this triaxiality suggests the existence of a second structure in the inner Galaxy, a double triaxiality or an inner ring. We argue that this is likely to be the signature of the end of the Galactic bar, at approximately 2.5-3 kpc, which is circumscribed by an inner pseudo-ring. No thick dust lane preceding the bar is detected and a hole in the dust distribution of the disc inside the bar radius is inferred. © 2005 RAS.