The State-of-the-art HST Astro-photometric Analysis of the Core of omega Centauri. I. The Catalog

作者：Bellini A; Anderson J; Bedin L R; King I R; van der Marel R P; Piotto G; Cool A

来源：Astrophysical Journal, 2017, 842(1): 6.

DOI：10.3847/1538-4357/aa7059

• globular clusters: individual (NGC 5139)
• Hertzsprung-Russell and C-M diagrams
• proper motions
• stars: Population II
• techniques: photometric

We have constructed the most. comprehensive catalog of photometry and proper motions ever assembled for a globular cluster (GC). The core of omega Cen has been imaged over 650 times through WFC3's UVIS and IR channels for the purpose of detector calibration. There exist from 4 to over 60 exposures through each of 26 filters. stretching continuously from F225W in the UV to F160W in the infrared. Furthermore, the 11 yr baseline between these data and a 2002 ACS survey has allowed us to more than double the proper-motion accuracy and triple the number of well-measured stars compared to our previous groundbreaking effort. This totally unprecedented complete spectral coverage of. over 470,000 stars within the cluster's core, from the tip of the red. giant branch down to the white dwarfs, provides the best astro-photometric observational database yet to understand the multiple-population phenomenon in any GC. In this first paper of the series, we describe in detail the data-reduction processes and deliver the astro-photometric catalog to the astronomical community.

• 出版日期2017-6-10