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J/A+A/524/A44       CN and CH line strengths in 12 globulars (Pancino+, 2010)

Low-resolution spectroscopy of main sequence stars belonging to 12 Galactic globular clusters. I. CH and CN band strength variations. Pancino E., Rejkuba M., Zoccali M., Carrera R. <Astron. Astrophys. 524, A44 (2010)> =2010A&A...524A..44P
ADC_Keywords: Clusters, globular ; Spectroscopy ; Stars, dwarfs ; Stars, early-type Keywords: stars: abundances - stars: early-type Abstract: Globular clusters show star-to-star abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, within which two subsequent generations of stars co-exist in globular clusters. Observations of chemical abundances in the main sequence and sub-giant branch stars allow us to investigate the signature of this chemically processed material without the complicating effects caused by stellar evolution and internal mixing. Our main goal is to investigate the carbon-nitrogen anti-correlation with low-resolution spectroscopy of 20-50 stars fainter than the first dredge-up in seven Galactic globular clusters (NGC288, NGC1851, NGC5927, NGC6352, NGC6388, and Pal12) with different properties. We complemented our observations with 47Tuc archival data, with four additional clusters from the literature (M15, M22, M55, NGC362), and with additional literature data on NGC288. Description: In this first paper, we measured the strength of the CN and CH band indices, which correlate with the N and C abundances, and we investigated the anti-correlation and bimodality of these indices. We compared rCN, the ratio of stars belonging to the CN-strong and weak groups, with 15 different cluster parameters. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 00 24 05.4 -72 04 53 NGC 104 = GCl 1 05 14 06.3 -40 02 50 NGC 1851 = GCl 9 00 52 45.3 -26 34 43 NGC 288 = GCl 2 15 28 00.4 -50 40 22 NGC 5927 = = GCl 35 17 25 29.2 -48 25 22 NGC 6352 = GCl 64 17 36 17.5 -44 44 08 NGC 6388 = GCl 70 19 10 51.8 -59 58 55 NGC 6752 = GCl 108 21 46 38.8 -21 15 03 Pal 12 = GCl 123 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 80 346 CH and CN bands index measurements
See also: J/A+A/486/437 : CN and CH line strengths in 8 Galactic GlCl (Kayser+, 2008) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 8 A8 --- GGC Cluster name 10- 13 I4 --- Seq Star sequential number in cluster 15- 23 F9.5 deg RAdeg Right ascension (J2000.0) 25- 33 F9.5 deg DEdeg Declination (J2000.0) 35- 40 F6.3 --- CN S3839(CN) band strength index 42- 47 F6.3 --- dCN S3839(CN) corrected for Teff and logg effects 49- 53 F5.3 --- e_CN Poisson uncertainty on S3839(CN) 55- 59 F5.3 --- CH CH4300 band strength index 61- 66 F6.3 --- dCH CH4300 corrected for Teff and logg effects 68- 72 F5.3 --- e_CH Poisson uncertainty on CH4300 74- 77 I4 km/s HRV Heliocentric radial velocity 79- 80 I2 km/s e_HRV Uncertainty on radial velocity
Acknowledgements: Elena Pancino, elena.pancino(at)oabo.inaf.it
(End) Elena Pancino [INAF-OABo, Italy], Patricia Vannier [CDS] 13-Sep-2010
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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