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J/ApJ/844/164  HST astro-photometric analysis of NGC5139. III.  (Bellini+, 2017)

The state-of-the-art HST astro-photometric analysis of the core of ω Centauri. III. The main sequence's multiple populations galore. Bellini A., Milone A.P., Anderson J., Marino A.F., Piotto G., van der Marel R.P., Bedin L.R., King I.R. <Astrophys. J., 844, 164 (2017)> =2017ApJ...844..164B
ADC_Keywords: Clusters, globular ; Stars, dwarfs Keywords: globular clusters: individual (NGC 5139); Hertzsprung-Russell and C-M diagrams; stars: Population II; techniques: photometric Abstract: We take advantage of the exquisite quality of the Hubble Space Telescope 26-filter astro-photometric catalog of the core of ωCen presented in the first paper of this series and the empirical differential-reddening correction presented in the second paper in order to distill the main sequence into its constituent populations. To this end, we restrict ourselves to the five most useful filters: the magic "trio" of F275W, F336W, and F438W, along with F606W and F814W. We develop a strategy for identifying color systems where different populations stand out most distinctly, then we isolate those populations and examine them in other filters where their subpopulations also come to light. In this way, we have identified at least 15 subpopulations, each of which has a distinctive fiducial curve through our five-dimensional photometric space. We confirm the MSa to be split into two subcomponents, and find that both the bMS and the rMS are split into three subcomponents. Moreover, we have discovered two additional MS groups: the MSd (which has three subcomponents) shares similar properties with the bMS, and the MSe (which has four subcomponents) has properties more similar to those of the rMS. We examine the fiducial curves together and use synthetic spectra to infer relative heavy-element, light-element, and helium abundances for the populations. Our findings show that the stellar populations and star formation history of ω Cen are even more complex than inferred previously. Finally, we provide as a supplement to the original catalog a list that identifies for each star which population it is most likely associated with. Description: The results presented here are the product of a massive effort, and represent a continuation of what we published in Bellini+ (2010, J/AJ/140/631). Paper I of this series (Bellini+ 2017, J/ApJ/842/6) describes the photometric techniques we adopted and applied to 650 individual exposures in 26 different bands. The photometry has been corrected for differential reddening and zero-point spatial variations in Bellini+ (2017ApJ...842....7B, Paper II). In this paper, we analyze the CMDs and the so-called "chromosome" maps (Milone+ 2017MNRAS.464.3636M) of the MS of the cluster, and finally identify at least 15 distinct stellar populations. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 9 478477 Multi-population identifier
See also: VII/195 : Globular Clusters in the Milky Way (Harris, 1996) J/ApJ/654/915 : Deep FORS1 BR photometry of omega Cen (Sollima+, 2007) J/AJ/140/631 : HST WFC3/UVIS photometry of omega Cen core (Bellini+, 2010) J/ApJ/722/1373 : ω Centauri giants abundances (Johnson+, 2010) J/ApJ/731/64 : Spectroscopy of 300 RGBs in ω Cen (Marino+, 2011) J/ApJ/791/107 : Parameters of NGC 5139 SGBs stars (Villanova+, 2014) J/ApJ/842/6 : Astro-photometric cat. of the core of NGC5139 (Bellini+, 2017) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 6 I6 --- ID [1/478477] Star ID, Bellini+ (2017, J/ApJ/842/6) 8- 9 I2 --- Pop [0/15]? Sub-population identity (1)
Note (1): Sub-population identity as follows: 0 = any star in the astro-photometric catalog not in a sub-population, including those that did not qualify for this analysis; 1 = MSa1 (Fe:+++, He:+++, N:?); 2 = MSa2 (Fe:+++, He:+++, N:?); 3 = bMS1 (Fe:+, He:+++, N:++); 4 = bMS2 (Fe:+, He:+++, N:++); 5 = bMS3 (Fe:+, He:+++, N:++); 6 = rMS1 (Fe:-, He:-, N:-); 7 = rMS2 (Fe:-, He:-, N:+); 8 = rMS3 (Fe:-, He:-, N:+); 9 = MSd1 (Fe:++, He:++, N:+); 10 = MSd2 (Fe:++, He:++, N:+); 11 = MSd3 (Fe:++, He:++, N:+); 12 = MSe1 (Fe:-, He:-, N:+); 13 = MSe2 (Fe:+, He:-, N:-); 14 = MSe3 (Fe:+, He:-, N:+); 15 = MSe4 (Fe:+, He:-, N:-). (One or more "+" signs indicate an increasingly high abundance, a "-" sign refers a relative abundance similar to that of the reference subpopulation, and a "?" means that that abundance cannot be qualitatively quantified with the tools at our disposal.)
History: From electronic version of the journal References: Bellini et al. Paper I. 2017ApJ...842....6B Cat. J/ApJ/842/6 Bellini et al. Paper II. 2017ApJ...842....7B Bellini et al. Paper III. 2017ApJ...844..164B This Catalog
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Mar-2018
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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