J/ApJ/758/110 CN and CH indexes in stars of NGC 6791 (Carrera, 2012)
Analysis of the CN and CH molecular band strengths in stars of the open
cluster NGC 6791.
Carrera R.
<Astrophys. J., 758, 110 (2012)>
=2012ApJ...758..110C 2012ApJ...758..110C
ADC_Keywords: Clusters, open ; Photometry, VRI ; Spectroscopy
Keywords: Galaxy: disk; open clusters and associations: individual: NGC 6791;
stars: abundances
Abstract:
Low-resolution SDSS/SEGUE spectra have been used to study the behavior
of the strengths of the CN and CH molecular bands in stars at
different evolutionary stages of the open cluster NGC 6791. We find a
significant spread in the strengths of the CN bands, more than twice
that expected from the uncertainties, although the bimodalities
observed in globular clusters are not clearly observed here. This
behavior is observed not only among red clump objects but also in
unevolved stars such as those in the main sequence and lower red giant
branch. In contrast, not all of the stars studied show significant
scatter in their CH strengths.
Description:
In the framework of the Sloan Extension for Galactic Understanding and
Exploration (SEGUE) survey (Yanny et al. 2009, Cat. J/AJ/137/4377),
low-resolution (R∼2000) spectra in the wavelength range of
3600-9200Å were obtained for more than 1000 stars observed in two
plates in the line of sight of NGC 6791. The reduced spectra, together
with the atmosphere parameters, radial velocities, etc., derived for
observed stars were made public in the eighth Sloan Digital Sky Survey
(SDSS) data release (Aihara et al. 2011ApJS..193...29A 2011ApJS..193...29A). To select
members of NGC 6791 from all of the observed stars we followed a
similar procedure as that described by Smolinski et al. (2011,
Cat. J/AJ/141/89).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 110 104 Index measurements for the sample stars
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See also:
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
J/A+A/543/A106 : UBVRI photometry in NGC6791 (Brogaard+, 2012)
J/A+A/525/A2 : Eclipsing binaries in NGC6791 (Brogaard+, 2011)
J/AJ/142/126 : CN & CH in SDSS Galactic globular clusters (Smolinski+, 2011)
J/AJ/141/89 : SEGUE stellar parameter pipeline. IV. (Smolinski+, 2011)
J/ApJ/729/L10 : KIC stars properties in NGC 6791 and NGC 6819 (Basu+, 2011)
J/A+A/524/A44 : CN and CH line strengths in 12 globulars (Pancino+, 2010)
J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)
J/A+A/486/437 : CN and CH line strengths in 8 Galactic GlCl (Kayser+, 2008)
J/AJ/136/2070 : SEGUE pipeline. III. (Allende Prieto+, 2008)
J/AJ/136/2050 : SEGUE stellar parameter pipeline. II. (Lee+, 2008)
J/A+A/471/515 : V light curves of NGC 6791 variable stars (De Marchi+, 2007)
J/AJ/134/1298 : CaII EWs in 29 Galactic clusters (Carrera+, 2007)
J/AJ/133/1585 : Stromgren photometry in NGC 6791 (Anthony-Twarog+, 2007)
J/AJ/129/2856 : Variable stars in NGC 6791 (Mochejska+, 2005)
J/AJ/129/656 : Infrared photometry of NGC 6791 (Carney+, 2005)
J/AJ/125/197 : CN abundances of the 47 Tuc main sequence (Harbeck+, 2003)
J/PASP/115/413 : BVI photometry in the open cluster NGC 6791 (Stetson+, 2003)
J/AJ/123/3460 : Low-amplitude variables in NGC 6791 (Mochejska+, 2002)
J/A+AS/114/1 : CCD UBVI photometry of NGC 6791 (Kaluzny+, 1995)
J/AJ/108/585 : UBVI photometry of NGC 6791 (Montgomery+, 1994)
J/MNRAS/243/492 : BV Photometry of NGC 6791 (Kaluzny, 1990)
http://www.sdss.org/ : SDSS home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Plate SDSS plate number
6- 8 I3 --- Fiber SDSS fiber number
10- 11 I2 h RAh Hour of Right Ascension (J2000)
13- 14 I2 min RAm Minute of Right Ascension (J2000)
16- 20 F5.2 s RAs Second of Right Ascension (J2000)
22- 22 A1 --- DE- Sign of the Declination (J2000)
23- 24 I2 deg DEd Degree of Declination (J2000)
26- 27 I2 arcmin DEm Arcminute of Declination (J2000)
29- 33 F5.2 arcsec DEs Arcsecond of Declination (J2000)
35- 39 F5.2 mag gmag [14.7/20.2] SDSS g band magnitude
41- 44 F4.2 mag g-r [0.3/1.5] SDSS (g-r) color index
46- 50 I5 --- SBG [1697/14328] Stetson et al. 2003 (J/PASP/115/413)
identifier (<Cl* NGC 6791 SBG NNNNN> in Simbad)
52- 56 F5.2 mag Vmag [13.8/19.7] The V band magnitude
58- 61 F4.2 mag V-I The (V-I) color index
63- 67 F5.2 --- S3839H [-0.5/0.5] The S3839H index (1)
69- 72 F4.2 --- e_S3839H Uncertainty in S3839H
74- 78 F5.2 --- S3839N [-0.3/0.8] The S3839N index (1)
80- 83 F4.2 --- e_S3839N Uncertainty in S3839N
85- 89 F5.2 --- S4142 [-0.5/0.1] The S4142 index (1)
91- 94 F4.2 --- e_S4142 Uncertainty in S4142
96-100 F5.2 --- CH4300 [-0.5/-0.2] The CH4300 index (1)
102-105 F4.2 --- e_CH4300 Uncertainty in CH4300
107-110 A4 --- Stage Evolutionary stage (MS=Main Sequence,
lRGB=lower Red Giant Branch, uRGB=upper RGB, or
RC=red clump)
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Note (1): the indexes are defined from the flux ratios in bands (Å):
S3839N = -2.5log[F(3846-3883)/F(3883-3916))]
(Norris et al. 1981ApJ...244..205N 1981ApJ...244..205N)
S3839H = -2.5log[F(3861-3884)/F(3894-3910))]
(Harbeck et al. 2003AJ....125..197H 2003AJ....125..197H)
S4142 = -2.5log(F(4120-4216)/F(4216-4290))
CH4300 = -2.5log[2F(4270-4260)/[F(4230-4260)+F(4390-4420]]
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Jul-2014