Reddening Distribution across the Center of the Globular Cluster ω Centauri

Citations Over TimeTop 11% of 2005 papers

Abstract

We present new medium-band uvby Stromgren and broad-band VI photometry for the central regions of the globular cluster Omega Cen. From this photometry we have obtained differential reddening estimates relative to two other globular clusters (M13 and NGC288) using a metallicity-independent, reddening-free temperature index, [c]=(u-v)-(v-b) - 0.2(b-y), for hot horizontal-branch (HB) stars (T_e> 8,500K). We estimate color excesses of these hot HB stars using optical and near-infrared colors, and find clumpy extinction variations of almost a factor of two within the area of the cluster core. In particular, the greatest density of more highly reddened objects appears to be shifted along the right ascension axis when compared with less reddened ones. These findings complicate photometric efforts to investigate the star formation history of Omega Cen.

Related Papers

• → Reddening, colour and metallicity of the M31 globular cluster system(2008)69 cited
• → Better age estimation using ultraviolet–optical colours: breaking the age–metallicity degeneracy(2007)78 cited
• → Photometry of the Globular Clusters of NGC 185(1974)18 cited
• → Deep Wide-Field Photometry of the NGC 5128 Globular Cluster System: A Progress Report(2002)
• → U Photometry of Globular Clusters in the Central Region of M 87(1988)