2008MNRAS.390.1388C

This paper concludes a systematic search for evidence of the Monoceros Ring and Canis Major dwarf galaxy around the Galactic plane. Presented here are the results for the Galactic longitude range of l = (280-025)°. Testing the claim that the Monoceros Ring encircles the entire Galaxy, this survey attempts to document the position of the Monoceros Ring with increasing Galactic longitude. Additionally, with the discovery of the purported Canis Major dwarf galaxy, searching for more evidence of its interaction is imperative for tracing its path through the Galaxy and understanding its role in the evolution of the Milky Way. Two new detections of the Monoceros Ring have been found at (l, b) = (280, +15)° and (300, +10)°. Interestingly, in general, there seem to be more detections above the plane than below it; in this survey, around 2/3 of the firm Monoceros Ring detections are in the north. This coincides with the northern detections appearing to be qualitatively denser and broader than their southern counterparts. The maximum of the Galactic warp in the south is also probed in this survey. It is found that these fields do not resemble those in the Canis Major region suggesting that the warp does not change the shape of the colour-magnitude diagram as is witnessed around Canis Major. The origins and morphology of the Monoceros Ring are still elusive primarily due to its enormous extent on the sky. Continued probing of the Galactic Outer Disc is needed before a consensus can be reached on its nature.