J/A+A/520/A95 Abundances of red giants in M54 and Sgr dSph (Carretta+, 2010)
Detailed abundances of a large sample of giant stars in M 54 and in
the Sagittarius nucleus.
Carretta E. Bragaglia A., Gratton R., Lucatello S., Bellazzini M.,
Catanzaro G., Leone F., Momany Y., Piotto G., D'Orazi V.
<Astron. Astrophys. 520, A95 (2010)>
=2010A&A...520A..95C 2010A&A...520A..95C
ADC_Keywords: Stars, giant ; Stars, late-type ; Abundances, [Fe/H]
Abundances, peculiar
Keywords: stars: abundances - stars: atmospheres - stars: Population II -
globular clusters: individual: NGC 6715 (M 54), NGC 5139 (omega Cen) -
globular clusters: general
Abstract:
Homogeneous abundances of light elements, alpha-elements, and Fe-group
elements from high-resolution FLAMES spectra are presented for 76 red
giant stars in NGC 6715 (M 54), a massive globular cluster (GC) lying
in the nucleus of the Sagittarius dwarf galaxy. We also derived
detailed abundances for 27 red giants belonging to the Sgr nucleus.
Our abundances assess the intrinsic metallicity dispersion (∼0.19dex,
rms scatter) of M 54, with the bulk of stars peaking at [Fe/H]~-1.6
and a long tail extending to higher metallicities, similar to
ω Cen. The spread in these probable nuclear star clusters
exceeds those of most GCs: these massive clusters are located in a
region intermediate between normal GCs and dwarf galaxies. M 54 shows
the Na-O anticorrelation, typical signature of GCs, which is instead
absent in the Sgr nucleus. The light elements (Mg, Al, Si)
participating to the high temperature Mg-Al cycle show that the entire
pattern of (anti)correlations produced by proton-capture reactions in
H-burning is clearly different between the most metal-rich and most
metal-poor components in the two most massive GCs in the Galaxy,
confirming early result based on the Na-O anticorrelation. As in
ω Cen, stars affected by most extreme processing, i.e. showing
the signature of more massive polluters, are those of the metal-rich
component. These observations can be understood if the burst of star
formation giving birth to the metal-rich component was delayed by as
much as 10-30Myr with respect to the metal-poor one. The evolution of
these massive GCs can be easily reconciled in the general scenario for
the formation of GCs recently sketched in Carretta et al.(2010a)
taking into account that ω Cen could have already incorporated
the surrounding nucleus of its progenitor and lost the rest of the
hosting galaxy while the two are still observable as distinct
components in M 54 and the surrounding field.
Description:
For a sample of ∼100 stars in M54 and the Sgr nucleus we give here:
identifications, coordinates, BVIK magnitudes, heliocentric RV
(table2); atmospheric parameters, [Fe/H] (table3); [O/Fe], [Na/Fe],
[Mg/Fe], [Al/Fe] (table5); the α-elements Si, Ca, and Ti
(table6); the Fe-peak elements Sc, V, Cr, Mn, Co, Ni, and Cu (table7).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 103 Identifications, positions, photometry and velocity
table3.dat 82 103 Teff, logg, [A/H],Vt, [Fe/H]I, [Fe/H]II
table5.dat 99 103 [O/Fe], [Na/Fe], [Mg/Fe], [Al/Fe]
table6.dat 90 103 [Si/Fe], [Ca/Fe], [Ti/Fe] I & II
table7.dat 161 103 [Sc/Fe], [V/Fe], [Cr/Fe],[Mn/Fe], [Co/Fe],
[Ni/Fe], [Cu/Fe]
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See also:
J/AJ/118/1245 : Elemental abundances in five stars in M54 (Brown+, 1999)
J/A+A/505/117 : Abundances of red giants in 15 globulars (Carretta+, 2009)
J/A+A/505/139 : Abundances of red giants in 17 globulars (Carretta+, 2009)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Cl M54 or SgrN
7- 14 I8 --- ID Identification number
18- 19 I2 h RAh Right ascension (J2000.0)
21- 22 I2 min RAm Right ascension (J2000.0)
24- 28 F5.2 s RAs Right ascension (J2000.0)
31 A1 --- DE- Declination sign (J2000.0)
32- 33 I2 deg DEd Declination (J2000.0)
35- 36 I2 arcmin DEm Declination (J2000.0)
38- 42 F5.2 arcsec DEs Declination (J2000.0)
46- 51 F6.3 mag Bmag B magnitude
53- 58 F6.3 mag Vmag V magnitude
60- 65 F6.3 mag Imag I magnitude
67- 72 F6.3 mag Kmag K magnitude
75- 80 F6.2 km/s RV1 ?=0 Heliocentric radial velocity
83- 88 F6.2 km/s RV2 ?=0 Heliocentric radial velocity
91- 99 A9 --- Instr Instrument (1)
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Note (1): Instruments as follows:
UVES = UVES
HR11 = Giraffe-HR11
HR13 = Giraffe-HR13
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Cl M54 or SgrN
7- 14 I8 --- ID Identification number
17- 20 I4 K Teff Effective temperature
23- 26 F4.2 [cm/s2] logg Gravity
29- 33 F5.2 [Sun] [A/H] Metallicity
36- 39 F4.2 km/s vt Microturbulent velocity
43- 44 I2 -- nFeI Number of FeI lines
49- 54 F6.3 [Sun] [Fe/H]1 FeI (neutral iron) abundance
57- 61 F5.3 [Sun] e_[Fe/H]1 rms on [Fe/H]1
64- 65 I2 -- nFeII ? Number of FeII lines
70- 75 F6.3 [Sun] [Fe/H]2 ? FeII (ionized iron) abundance
78- 82 F5.3 [Sun] e_[Fe/H]2 ? rms on [Fe/H]2
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Cl M54 or SgrN
7- 14 I8 --- ID Identification number
17 I1 --- nO number of O lines
22- 26 F5.2 [Sun] [O/Fe] Oxygen abundance
29- 32 F4.2 [Sun] e_[O/Fe] ? rms on [O/Fe]
37 I1 --- nNa ? Number of Na lines
42- 46 F5.2 [Sun] [Na/Fe] ? Sodium abundance
49- 52 F4.2 [Sun] e_[Na/Fe] ? rms on [Na/Fe]
57 I1 --- nMg ? Number of Mg lines
62- 66 F5.2 [Sun] [Mg/Fe] ? Magnesium abundance
69- 72 F4.2 [Sun] e_[Mg/Fe] ? rms on [Mg/Fe]
77 I1 --- nAl ? Number of Al lines
81- 85 F5.2 [Sun] [Al/Fe] ? Aluminum abundance
88- 91 F4.2 [Sun] e_[Al/Fe] ? rms on [Al/Fe]
96 I1 --- f_[O/Fe] [0,1]? 0=upper limit; 1=measure of Oxygen
99 I1 --- f_[Al/Fe] [0,1]? 0=upper limit; 1=measure of Aluminium
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Cl M54 or SgrN
6- 13 I8 --- ID Ndentification number
16- 17 I2 --- nSi Number of Si lines
21- 25 F5.2 [Sun] [Si/Fe] Silicon abundance
29- 32 F4.2 [Sun] e_[Si/Fe] ? rms on [Si/Fe]
36- 37 I2 --- nCa ? Number of Ca lines
42- 46 F5.2 [Sun] [Ca/Fe] ? Calcium abundance
50- 53 F4.2 [Sun] e_[Ca/Fe] ? rms on [Ca/Fe]
57- 58 I2 --- nTi1 ? Number of Ti I lines
64- 68 F5.2 [Sun] [Ti/Fe]1 ? Titanium (neutral) abundance
72- 75 F4.2 [Sun] e_[Ti/Fe]1 ? rms on [Ti/Fe]1
80 I1 --- nTi2 ? Number of Ti II lines
86- 90 F5.2 [Sun] [Ti/Fe]2 ? Titanium (ionized) abundance
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Cl M54 or SgrN
6- 13 I8 --- ID Identification number
16- 17 I2 --- nSc Number of Sc lines
23- 27 F5.2 [Sun] [Sc/Fe] Scandium abundance
31- 34 F4.2 [Sun] e_[Sc/Fe] ? rms on [Sc/Fe]
39- 40 I2 --- nV ? Number of V lines
46- 50 F5.2 [Sun] [V/Fe] ? Vanadium abundance
54- 57 F4.2 [Sun] e_[V/Fe] ? rms on [V/Fe]
61- 62 I2 --- nCr ? Number of Cr lines
68- 72 F5.2 [Sun] [Cr/Fe] ? Cromium abundance
76- 79 F4.2 [Sun] e_[Cr/Fe] ? rms on [Cr/Fe]
83- 84 I2 --- nMn ? Number of Mn lines
90- 94 F5.2 [Sun] [Mn/Fe] ? Manganese abundance
98-101 F4.2 [Sun] e_[Mn/Fe] ? rms on [Mn/Fe]
106-107 I2 --- nCo ? Number of Co lines
113-117 F5.2 [Sun] [Co/Fe] ? Cobalt abundance
121-124 F4.2 [Sun] e_[Co/Fe] ? rms on [Co/Fe]
129-130 I2 --- nNi ? Number of Ni lines
136-140 F5.2 [Sun] [Ni/Fe] ? Nichel abundance
144-147 F4.2 [Sun] e_[Ni/Fe] ? rms on [Ni/Fe]
152 I1 --- nCu ? Number of Cu lines
157-161 F5.2 [Sun] [Cu/Fe] ? Copper abundance
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Acknowledgements:
Eugenio Carretta, eugenio.carretta(at)oabo.inaf.it
(End) Eugenio Carretta [Bologna Obs.], Francois Ochsenbein [CDS] 16-Aug-2010