2008/02/25 by Shogo Nishiyama, Tetsuya Nagata, Motohide Tamura +4 · 6 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Bulge #Center (category theory) #Extinction (optical mineralogy) #Galactic Center #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitational lens #Infrared #Interstellar medium #Optics #Physics #Stellar, planetary, and galactic studies #Telescope #Wavelength #astro-ph
paper · pdf · doi:10.1086/587791
8 pages, 7 figures, Accepted for publication in ApJ
arxiv created 2008/02/25 · openalex publication_date 2008/06/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have determined the ratios of total to selective extinction directly from observations in the optical V band and near-infrared J band toward the Galactic center. The OGLE (Optical Gravitational Lensing Experiment) Galactic bulge fields have been observed with the SIRIUS camera on the Infrared Survey Facility telescope, and we obtain A V / E V – J = 1.251 ± 0.014 and A J / E V – J = 0.225 ± 0.007. From these ratios, we derive A J / A V = 0.188 ± 0.005; combining this with the near-infrared extinction ratios obtained in Paper I for more reddened fields near the Galactic center, we obtain A V : A J : A H : A K s = 1:0.188:0.108:0.062, which implies steeply declining extinction toward longer wavelengths. In particular, it is striking that the K s -band extinction is ≈1/16 the visual extinction A V , much smaller than the 1/10 usually employed.