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

Journal Article · Sat Jun 10 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA7059· OSTI ID:22663531

Bellini, A.; Anderson, J.; Van der Marel, R. P. ^[1]; Bedin, L. R.; Piotto, G. ^[2]; King, I. R. ^[3]

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1. Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)
2. Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, v.co dell’Osservatorio 5, Padova I-35122 (Italy)
3. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA (United States)

We have constructed the most comprehensive catalog of photometry and proper motions ever assembled for a globular cluster (GC). The core of ω 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.

• OSTI ID: 22663531
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 842; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCURACY
CALIBRATION
CATALOGS
COMPARATIVE EVALUATIONS
IMAGES
PHOTOMETRY
PROPER MOTION
REDUCTION
WHITE DWARF STARS