J/ApJ/810/148 Red giant abundances in NGC 2808 (Carretta, 2015)
Five groups of red giants with distinct chemical composition in the
globular cluster NGC 2808.
Carretta E.
<Astrophys. J., 810, 148 (2015)>
=2015ApJ...810..148C 2015ApJ...810..148C (SIMBAD/NED BibCode)
ADC_Keywords: Abundances, [Fe/H] ; Clusters, globular ; Stars, giant
Keywords: stars: abundances; stars: atmospheres; stars: Population II
Abstract:
The chemical composition of multiple populations in the massive
globular cluster (GC) NGC 2808 is addressed with the homogeneous
abundance reanalysis of 140 red giant branch stars. UVES spectra for
31 stars and GIRAFFE spectra for the other giants were analyzed with
the same procedures used for about 2500 giants in 23 GCs in our FLAMES
survey, deriving abundances of Fe, O, Na, Mg, Si, Ca, Ti, Sc, Cr, Mn,
and Ni. Iron, elements from α capture, and those in the Fe group
do not show intrinsic scatter. On our UVES scale, the metallicity of
NGC 2808 is [Fe/H]=-1.29±0.005±0.034 (±statistical±systematic
error) with σ=0.030 (31 stars). The main features related to
proton-capture elements are retrieved, but the improved statistics and
the smaller associated internal errors allow us to uncover five
distinct groups of stars along the Na-O anticorrelation. We observe
large depletions in Mg, anticorrelated with enhancements of Na and
also Si, suggestive of unusually high temperatures for proton
captures. About 14% of our sample is formed by giants with solar or
subsolar [Mg/Fe] ratios. Using the [Na/Mg] ratios, we confirm the
presence of five populations with different chemical compositions that
we call P1, P2, I1, I2, and E in order of decreasing Mg and increasing
Na abundances. Statistical tests show that the mean ratios in any pair
of groups cannot be extracted from the same parent distribution. The
overlap with the five populations recently detected from UV photometry
is good but not perfect, confirming that more distinct components
probably exist in this complex GC.
Description:
In the present paper we provide the full derivation of the atmospheric
parameters for all stars with available spectra from previous analyses
(see Carretta+ 2006A&A...450..523C 2006A&A...450..523C and Caretta 2014ApJ...795L..28C 2014ApJ...795L..28C).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 61 140 Adopted atmospheric parameters and derived
iron abundances in NGC 2808
table4.dat 71 140 Abundances of proton-capture elements in
stars of NGC 2808
table5.dat 86 140 Abundances of α-capture and Fe-peak
elements in stars of NGC 2808
table6.dat 55 31 Abundances of TiII, CrII, and Mn in stars
of NGC 2808 observed with UVES
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See also:
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
J/MNRAS/449/4038 : Li abundance of giants in 3 GCs (D'Orazi+, 2015)
J/A+A/578/A116 : Abundances of red giants in NGC6093 (M80) (Carretta+, 2015)
J/A+A/564/A60 : NGC 4833 Na-O measured with FLAMES (Carretta+, 2014)
J/MNRAS/437/1609 : NGC 2808 HB stars abundances (Marino+, 2014)
J/A+A/557/A138 : Detailed chemical abundances in NGC 362 (Carretta+ 2013)
J/ApJ/769/40 : Potassium abundance in red giants of GCs (Carretta+, 2013)
J/ApJ/760/86 : Equivalent widths for 13 NGC2419 RGB stars (Cohen+, 2012)
J/ApJ/750/L14 : Abundances of red giants in NGC 6752 (Carretta+, 2012)
J/A+A/542/A129 : NGC 2808 central kinematics (Luetzgendorf+, 2012)
J/A+A/534/A123 : Horizontal branch stars in NGC 2808 (Gratton+, 2011)
J/A+A/533/A69 : Spectroscopy of 124 RGB stars in NGC 1851 (Carretta+, 2011)
J/A+A/528/A127 : Radial velocities in the globular NGC 2808 (Moni Bidin+, 2011)
J/A+A/520/A95 : Abundances of red giants in M54 and Sgr dSph (Carretta+, 2010)
J/ApJ/712/L21 : Calcium abundances in 17 globular clusters (Carretta+, 2010)
J/A+A/505/139 : Abundances of red giants in 17 GCs (Carretta+, 2009)
J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009)
J/A+A/490/625 : Abundances of NGC 6121 red giants (Marino+, 2008)
J/A+A/464/967 : Abundances of red giants in NGC 6388 (Carretta+, 2007)
J/A+A/464/953 : Abundances of red giants in NGC 6441 (Gratton+, 2007)
J/A+A/464/939 : Abundances of red giants in NGC 6218 (Carretta+, 2007)
J/A+A/464/927 : Abundances of red giants in NGC 6752 (Carretta+, 2007)
J/A+A/455/271 : Abundances of red giants in NGC 6441 (Gratton+, 2006)
J/AJ/131/1766 : Abundances and equivalent widths in NGC 2808 (Carretta, 2006)
J/A+A/417/597 : Radial velocities in 4 globular clusters (Recio-Blanco+, 2004)
J/A+A/413/343 : RGB stars in NGC 2808 (Cacciari+, 2004)
J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003)
J/AJ/121/327 : Metal Abundances of NGC6819 Red Clump Stars (Bragaglia+, 2001)
J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)
J/A+A/350/955 : Atmospheric parameters in metal-poor stars II (Gratton+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 1 A1 --- f_ID Observation flag; U: observed with UVES;
otherwise GIRAFFE
4- 8 I5 --- ID [7183/56924] Star ID from Bedin et al.
(2000A&A...363..159B 2000A&A...363..159B)
10- 13 I4 K Teff [3863/5036] Stellar Effective Temperature
15- 18 F4.2 [cm/s2] log(g) [0.3/2.5] Stellar Surface Gravity
20- 24 F5.2 [Sun] [A/H] [-1.3/-1] Input metallicity
26- 29 F4.2 km/s vt [0.6/2] Microturbulent velocity
31- 32 I2 --- o_[Fe/H]I [15/93] Number of FeI lines
34- 39 F6.3 [Sun] [Fe/H]I [-1.3/-1] Abundance [Fe/H]I
41- 45 F5.3 [Sun] e_[Fe/H]I [0.03/0.2] rms uncertainty on [Fe/H]I
47- 48 I2 --- o_[Fe/H]II [3/11]? Number of FeII lines
50- 55 F6.3 [Sun] [Fe/H]II [-1.3/-1]? Abundance [Fe/H]II
57- 61 F5.3 [Sun] e_[Fe/H]II [0.005/0.3]? rms uncertainty on [Fe/H]II
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 1 A1 --- f_ID Observation flag; U: observed with UVES;
otherwise GIRAFFE
3- 7 I5 --- ID [7183/56924] Star ID from Bedin et al.
(2000A&A...363..159B 2000A&A...363..159B)
9- 9 I1 --- o_[O/Fe] [0/2] Number of O lines
11- 16 F6.3 [Sun] [O/Fe] [-1/0.5]? Abundance [O/Fe]
18- 22 F5.3 [Sun] e_[O/Fe] [0/0.2]? rms uncertainty on [O/Fe]
24- 24 I1 --- o_[Na/Fe] [1/4] Number of Na lines
26- 31 F6.3 [Sun] [Na/Fe] [-0.2/0.9]? Abundance [Na/Fe]
33- 37 F5.3 [Sun] e_[Na/Fe] [0/0.2]? rms uncertainty on [Na/Fe]
39- 39 I1 --- o_[Mg/Fe] [0/3] Number of Mg lines
41- 46 F6.3 [Sun] [Mg/Fe] [-0.2/0.5]? Abundance [Mg/Fe]
48- 52 F5.3 [Sun] e_[Mg/Fe] [0.002/0.2]? rms uncertainty on [Mg/Fe]
54- 55 I2 --- o_[Si/Fe] [2/13] Number of Si lines
57- 62 F6.3 [Sun] [Si/Fe] [0.1/0.5] Abundance [Si/Fe]
64- 68 F5.3 [Sun] e_[Si/Fe] [0.02/0.3] rms uncertainty on [Si/Fe]
70- 71 I2 --- limO [0/1] Flag: Upper limits (limO=0);
detections (=1) for O
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 1 A1 --- f_ID Observation flag; U: observed with UVES;
otherwise GIRAFFE
3- 7 I5 --- ID [7183/56924] Star ID from Bedin et al.
(2000A&A...363..159B 2000A&A...363..159B)
9- 10 I2 --- o_[Ca/Fe] [1/18] Number of Ca lines
12- 17 F6.3 [Sun] [Ca/Fe] [0.2/0.5] Abundance [Ca/Fe]
19- 23 F5.3 [Sun] e_[Ca/Fe] [0.02/0.3]? rms uncertainty on [Ca/Fe]
25- 26 I2 --- o_[Ti/Fe]I [2/10] Number of Ti lines
28- 33 F6.3 [Sun] [Ti/Fe]I [0.1/0.3] Abundance [Ti/Fe]I
35- 39 F5.3 [Sun] e_[Ti/Fe]I [0/0.2] rms uncertainty on [Ti/Fe]I
41- 41 I1 --- o_[Sc/Fe]II [2/8] Number of Sc lines
43- 48 F6.3 [Sun] [Sc/Fe]II [-0.1/0.1] Abundance [Sc/Fe]II
50- 54 F5.3 [Sun] e_[Sc/Fe]II [0.006/0.3] rms uncertainty on [Sc/Fe]II
56- 57 I2 --- o_[Cr/Fe]I [1/26] Number of Cr lines
59- 64 F6.3 [Sun] [Cr/Fe]I [-0.2/0.03] Abundance [Cr/Fe]I
66- 70 F5.3 [Sun] e_[Cr/Fe]I [0.04/0.3]? rms uncertainty on [Cr/Fe]I
72- 73 I2 --- o_[Ni/Fe] [2/32] Number of Ni lines
75- 80 F6.3 [Sun] [Ni/Fe] [-0.2/-0.02] Abundance [Ni/Fe]
82- 86 F5.3 [Sun] e_[Ni/Fe] [0.007/0.3] rms uncertainty on [Ni/Fe]
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- f_ID Observation flag; U: observed with UVES;
otherwise GIRAFFE
4- 8 I5 --- ID [7536/56032] Star ID from Bedin et al.
(2000A&A...363..159B 2000A&A...363..159B)
10- 11 I2 --- o_[Ti/Fe]II [5/12]? Number of Ti lines
13- 18 F6.3 [Sun] [Ti/Fe]II [0.1/0.3]? Abundance [Ti/Fe]II
20- 24 F5.3 [Sun] e_[Ti/Fe]II [0.04/0.5]? rms uncertainty on [Ti/Fe]II
26- 27 I2 --- o_[Cr/Fe]II [2/17] Number of Cr lines
29- 34 F6.3 [Sun] [Cr/Fe]II [-0.09/0.04] Abundance [Cr/Fe]II
36- 40 F5.3 [Sun] e_[Cr/Fe]II [0.05/0.4] rms uncertainty on [Cr/Fe]II
42- 42 I1 --- o_[Mn/Fe] [3] Number of Mn lines
44- 49 F6.3 [Sun] [Mn/Fe] [-0.5/-0.2] Abundance [Mn/Fe]
51- 55 F5.3 [Sun] e_[Mn/Fe] [0.009/0.3] rms uncertainty on [Mn/Fe]
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Acknowledgements:
Eugenio Carretta [Osservatorio Astronomico di Bologna (OABO) - INAF] for
the coordinates of table 1.
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Dec-2015