A Distinct Structure Inside the Galactic Bar
Abstract
We present the result of a near-infrared (J H Ks) survey along the Galactic plane, -10.5deg < l < +10.5deg and b=+1.0deg, with the IRSF 1.4m telescope and the SIRIUS camera. Ks vs. H-Ks color-magnitude diagrams reveal a well-defined population of red clump (RC) stars whose apparent magnitude peak changes continuously along the Galactic plane, from Ks=13.4 at l=-10deg to Ks=12.2 at l=+10deg after dereddening. This variation can be explained by the bar-like structure found in previous studies, but we find an additional inner structure at |l| < 4deg, where the longitude - apparent magnitude relation is distinct from the outer bar, and the apparent magnitude peak changes by only 0.1 mag over the central 8deg. The exact nature of this inner structure is as yet uncertain.
Cite
@article{arxiv.astro-ph/0502058,
title = {A Distinct Structure Inside the Galactic Bar},
author = {Shogo Nishiyama and Tetsuya Nagata and Daisuke Baba and Yasuaki Haba and Ryota Kadowaki and Daisuke Kato and Mikio Kurita and Chie Nagashima and Takahiro Nagayama and Yuka Murai and Yasushi Nakajima and Motohide Tamura and Hidehiko Nakaya and Koji Sugitani and Takahiro Naoi and Noriyuki Matsunaga and Toshihiko Tanabe and Nobuhiko Kusakabe and Shuji Sato},
journal= {arXiv preprint arXiv:astro-ph/0502058},
year = {2009}
}
Comments
8 pages, 4 figures. accepted by ApJL