J/MNRAS/446/3319 Line list for the NGC 1851 stars (Yong+, 2015)
CNO abundances in the globular clusters NGC 1851 and NGC 6752.
Yong D., Grundahl F., Norris J.E.
<Mon. Not. R. Astron. Soc., 446, 3319-3329 (2015)>
=2015MNRAS.446.3319Y 2015MNRAS.446.3319Y (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Magnitudes ; Effective temperatures ;
Abundances ; Spectroscopy
Keywords: Stars: abundances - Galaxy: abundances -
globular clusters: individual: NGC 1851 -
globular clusters: individual: NGC 6752
Abstract:
We measure the C+N+O abundance sum in red giant stars in two Galactic
globular clusters, NGC 1851 and NGC 6752. NGC 1851 has a split
subgiant branch which could be due to different ages or C+N+O content
while NGC 6752 is representative of the least complex globular
clusters. For NGC 1851 and NGC 6752, we obtain average values of
A(C+N+O)=8.16±0.10 (σ=0.34) and 7.62±0.02 (σ=0.06),
respectively. When taking into account the measurement errors, we find
a constant C+N+O abundance sum in NGC 6752. The C+N+O abundance
dispersion is only 0.06 dex, and such a result requires that the
source of the light element abundance variations does not increase the
C+N+O sum in this cluster. For NGC 1851, we confirm a large spread in
C+N+O. In this cluster, the anomalous RGB has a higher C+N+O content
than the canonical RGB by a factor of 4 (∼0.6 dex). This result
lends further support to the idea that the two subgiant branches in
NGC 1851 are roughly coeval, but with different CNO abundances.
Description:
The targets were selected from the Stromgren uvby photometry from
Grundahl et al. (1999ApJ...524..242G 1999ApJ...524..242G). Observations of these targets
were obtained using the multiobject spectrograph FLAMES/GIRAFFE
(Pasquini et al. 2002Msngr.110....1P 2002Msngr.110....1P) in IFU mode. The field of view
is 25 arcmin and there are 15 IFU units each of which has an aperture
of 2x3 arcsec2 consisting of 20 square spaxels of length 0.52 arcsec.
For NGC 1851, we obtained spectra using the HR4 (R=32500:∼4300 Å;
total exposure time of 7.9 h), HR13 (R=36000:∼6300 Å, total exposure
time of 1.4 h) and HR19B (R=35000:∼8000 Å, total exposure time
of 1.3 h) gratings.
Objects:
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RA (ICRS) DE Designation(s)
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05 14 06.76 -40 02 47.6 NGC 1851 = GCl 9
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 88 15 Stellar parameters and CNO abundances
for NGC 1851
table4.dat 115 43 Line list for the NGC 1851 stars
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See also:
J/A+A/333/479 : NGC 1851 dynamical and evolutionary properties
(Saviane+ 1998)
J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003)
J/A+A/533/A69 : Spectroscopy of 124 RGB stars in NGC 1851 (Carretta+, 2011)
J/MNRAS/442/3044 : Photometry and abundances of NGC1851 stars (Marino+, 2014)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Star name (NR NNNN)
9- 11 I3 --- OName ?=- Other star name (NNN) (1)
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 23 F5.2 s RAs Second of Right Ascension (J2000)
25 A1 --- DE- Sign of the Declination (J2000)
26- 27 I2 deg DEd Degree of Declination (J2000)
29- 30 I2 arcmin DEm Arcminute of Declination (J2000)
32- 36 F5.2 arcsec DEs Arcsecond of Declination (J2000)
38- 42 F5.2 mag Vmag V-band magnitude
44- 46 A3 --- CMD Group from colour-magnitude diagram
48- 51 I4 K Teff Effective temperature
53- 56 F4.2 [cm/s2] log(g) Surface gravity
58- 61 F4.2 km/s Vt ?=- Microturbulent velocity
62 A1 --- n_Vt [a] Note on Vt (2)
64- 68 F5.2 [-] [Fe/H] ?=- Metallicity
70- 73 F4.2 [-] C ?=- Carbon abundance
75- 78 F4.2 [-] N ?=- Nitrogen abundance (3)
80- 83 F4.2 [-] O ?=- Oxygen abundance
85- 88 F4.2 [-] C+N+O ?=- Carbon nitrogen and oxygen abundance sum
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Note (1): Star names from Stetson (1981AJ.....86..687S 1981AJ.....86..687S),
Cl* NGC 1851 STET NNN in simbad.
Note (2): Note as follows:
a= Spectrum affected by TiO.
Note (3): The N abundances are from CN and have been adjusted by -0.44 dex (see
Sections 4.1 and 4.2 for details).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm Lambda Wavelength (Å)
9- 12 F4.1 --- Species Species identifier (1)
14- 17 F4.2 eV LEP Lower Excitation Potential
19- 23 F5.2 [-] log(gf) Log of the oscillator strength
25- 29 F5.1 0.1pm Line1 ?=- NR 712 line wavelength (mÅ)
31- 35 F5.1 0.1pm Line2 ?=- NR 1290 line wavelength (mÅ)
37- 41 F5.1 0.1pm Line3 ?=- NR 1469 line wavelength (mÅ)
43- 47 F5.1 0.1pm Line4 ?=- NR 2352 line wavelength (mÅ)
49- 53 F5.1 0.1pm Line5 ?=- NR 2953 line wavelength (mÅ)
55- 59 F5.1 0.1pm Line6 ?=- NR 3213 line wavelength (mÅ)
61- 65 F5.1 0.1pm Line7 ?=- NR 3272 line wavelength (mÅ)
67- 71 F5.1 0.1pm Line8 ?=- NR 4740 line wavelength (mÅ)
73- 77 F5.1 0.1pm Line9 ?=- NR 5171 line wavelength (mÅ)
79- 83 F5.1 0.1pm Line10 ?=- NR 5246 line wavelength (mÅ)
85- 89 F5.1 0.1pm Line11 ?=- NR 5543 line wavelength (mÅ)
91- 95 F5.1 0.1pm Line12 ?=- NR 6217 line wavelength (mÅ)
97-101 F5.1 0.1pm Line13 ?=- NR 6221 line wavelength (mÅ)
103-107 F5.1 0.1pm Line14 ?=- NR 6250 line wavelength (mÅ)
109-113 F5.1 0.1pm Line15 ?=- NR 8066 line wavelength (mÅ)
115 A1 --- Source [ABC] Source (2)
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Note (1): The digits to the left of the decimal point are the atomic number.
The digit to the right of the decimal point is the ionization state
(0=neutral, 1=singly ionized).
Note (2): Source as follows:
A = Gratton et al. (2003, J/A+A/404/187);
B = Oxford group including Blackwell et al. (1979MNRAS.186..633B 1979MNRAS.186..633B;
1980MNRAS.191..445B 1980MNRAS.191..445B; 1986MNRAS.220..549B 1986MNRAS.220..549B), Blackwell, Petford & Shallis
(1979MNRAS.186..657B 1979MNRAS.186..657B), and Blackwell, Lynas-Gray & Smith
(1995A&A...296..217B 1995A&A...296..217B);
C = Yong et al. (2005A&A...438..875Y 2005A&A...438..875Y).
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 02-Nov-2017