J/MNRAS/450/815 Red giants in NGC 5286 (Marino+, 2015)
Iron and s-elements abundance variations in NGC 5286: comparison with
'anomalous' globular clusters and Milky Way satellites.
Marino A.F., Milone A.P., Karakas A.I., Casagrande L., Yong D.,
Shingles L., Da Costa G., Norris J.E., Stetson P.B., Lind K., Asplund M.,
Collet R., Jerjen H., Sbordone L., Aparicio A., Cassisi S.
<Mon. Not. R. Astron. Soc., 450, 815-845 (2015)>
=2015MNRAS.450..815M 2015MNRAS.450..815M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Stars, giant ; Abundances
Keywords: stars: abundances - globular clusters: general -
globular clusters: individual: NGC 5286
Abstract:
We present a high-resolution spectroscopic analysis of 62 red giants
in the Milky Way globular cluster (GC) NGC 5286. We have determined
abundances of representative light proton-capture, α, Fe-peak
and neutron-capture element groups, and combined them with photometry
of multiple sequences observed along the colour-magnitude diagram. Our
principal results are: (i) a broad, bimodal distribution in s-process
element abundance ratios, with two main groups, the s-poor and s-rich
groups; (ii) substantial star-to-star Fe variations, with the s-rich
stars having higher Fe, e.g. <[Fe/H]s-rich-<[Fe/H]>s-poor∼0.1dex;
and (iii) the presence of O-Na-Al (anti)correlations in both stellar
groups. We have defined a new photometric index, cBVI=(B-V)-(V-I),
to maximize the separation in the colour-magnitude diagram between the
two stellar groups with different Fe and s-element content, and this
index is not significantly affected by variations in light elements
(such as the O-Na anticorrelation). The variations in the overall
metallicity present in NGC 5286 add this object to the class of
anomalous GCs. Furthermore, the chemical abundance pattern of NGC 5286
resembles that observed in some of the anomalous GCs, e.g. M 22, NGC
1851, M 2, and the more extreme ω Centauri, that also show
internal variations in s-elements, and in light elements within stars
with different Fe and s-elements content. In view of the common
variations in s-elements, we propose the term s-Fe-anomalous GCs to
describe this sub-class of objects. The similarities in chemical
abundance ratios between these objects strongly suggest similar
formation and evolution histories, possibly associated with an origin
in tidally disrupted dwarf satellites.
Description:
We used photometric data from the Wide Field Imager (WFI) of the Max
Planck 2.2m telescope at La Silla collected through the U filter under
the SUrvey of Multiple pOpulations in GCs (SUMO; programme
088.A-9012-A, PI. A. F. Marino). These U images consist of
14x850s+3x300s collected on 2012 February. Additionally, we have used
B, V, and I photometry from the archive maintained by P.B. Stetson
(Stetson, 2000PASP..112..925S 2000PASP..112..925S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 93 Coordinates, basic photometric data and radial
velocities for the stars in the field of view
of NGC5286
table3.dat 92 205 *Line list for the program stars
table4.dat 135 55 Adopted atmospheric parameters and chemical
abundances derived for the NGC5286 stars
observed with GIRAFFE
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Note on table3.dat: For the UVES targets we list the measured EWs. For GIRAFFE,
we synthesized the same lines used for UVES, in the common spectral range
6120-6400Å; a few lines have been used only for GIRAFFE.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Inst Instrument
9- 19 A11 --- Name Name (N5286_NNNNA)
21- 22 I2 h RAh Right ascension (J2000)
24- 25 I2 min RAm Right ascension (J2000)
27- 31 F5.2 s RAs Right ascension (J2000)
33 A1 --- DE- Declination sign (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 43 F4.1 arcsec DEs Declination (J2000)
45- 50 F6.3 mag Bmago Original B magnitude
52- 57 F6.3 mag Vmago Original V magnitude
59- 64 F6.3 mag Imago Original I magnitude
66- 71 F6.3 mag Bmagc ?=- Corrected B magnitude
73- 78 F6.3 mag Vmagc ?=- Corrected V magnitude
80- 85 F6.3 mag Imagc ?=- Corrected I magnitude
87- 92 F6.2 km/s RV Radial velocity
94- 99 A6 --- Memb Probable cluster membership
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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 A1 --- Note [G] G: GIRAFFE additional synthetised lines
3- 10 F8.3 0.1nm lambda Wavelength
12- 15 F4.1 --- Species Species
17- 21 F5.3 eV L.E.P. Excitation potential
23- 28 F6.3 [-] loggf Total oscillator strength
30- 34 F5.1 0.1nm 1219U ?=- Equivalent width for N5286_1219U star
35 A1 --- n_1219U [s] s for saturated
38- 42 F5.1 0.1nm 1439U ?=- Equivalent width for N5286_1439U star
43 A1 --- n_1439U [s] s for saturated
46- 50 F5.1 0.1nm 859U ?=- Equivalent width for N5286_859U star
51 A1 --- n_859U [s] s for saturated
54- 58 F5.1 0.1nm 1309U ?=- Equivalent width for N5286_1309U star
59 A1 --- n_1309U [s] s for saturated
62- 66 F5.1 0.1nm 579U ?=- Equivalent width for N5286_579U star
67 A1 --- n_579U [s] s for saturated
70- 74 F5.1 0.1nm 1339U ?=- Equivalent width for N5286_1339U star
75 A1 --- n_1339U [s] s for saturated
78- 82 F5.1 0.1nm 177U ?=- Equivalent width for N5286_177U star
83 A1 --- n_177U [s] s for saturated
86- 92 A7 --- r_loggf Refierence for loggf (1)
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Note (1): References as follows:
1 = Kurucz compendium (AIP Conf. Proc. Vol. 1171, Recent Directions in
Astrophysical Quantitative Spectroscopy and Radiation Hydrodynamics.
Hubeny I., Stone J. M., MacGregor K., Werner K., editors.
New York: Am. Inst. Phys.; 2009. p. 43.)
2 = Fuhr & Wiese (CRC Handbook of Chemistry and Physics. 90th edn. Lide D.R.,
editor. FL: CRC Press, Boca Raton; 2009. p. 10)
3 = Yong et al. (2014MNRAS.441.3396Y 2014MNRAS.441.3396Y)
4 = NIST
5 = Gaia-ESO linelist (Heiter et al., in prep.)
6 = Yong et al. (2013MNRAS.434.3542Y 2013MNRAS.434.3542Y)
7 = Melendez & Barbuy (2009A&A...497..611M 2009A&A...497..611M)
8 = Johnson & Pilachowsky (2010, Cat. J/ApJ/722/1373)
9 = Bielski (1975, J. Quant. Spectrosc. Radiat. Transfer, 15,463),
Kurucz & Bell (1995, CD-ROM. Cambridge, MA: Smithsonian Astrophysical
Observatory)
10 = Hannaford et al. (1982ApJ...261..736H 1982ApJ...261..736H)
11 = Biemont et al. (1981ApJ...248..867B 1981ApJ...248..867B)
12 = Gallagher (1967, Phys. Rev. 157, 24),
Sneden et al. (2000AJ....120.1351S 2000AJ....120.1351S)
13 = Gallagher (1967, Phys. Rev. 157, 24),
Burris et al. (2000ApJ...544..302B 2000ApJ...544..302B)
14 = Gallagher (1967, Phys. Rev. 157, 24),
Sneden et al. (1996ApJ...467..819S 1996ApJ...467..819S)
15 = Lawler, Bonvallet & Sneden (2001ApJ...556..452L 2001ApJ...556..452L)
16 = Sneden et al. (2009, Cat. J/ApJS/182/80)
17 = Ivarsson et al. (2001, Phys. Scr. , 61, 455)
18 = Li et al. (2007, Phys. Scr. 76, 577)
19 = Lawler et al. (2001ApJ...563.1075L 2001ApJ...563.1075L)
HFS = hyperfine structure
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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- 11 A11 --- Name Name (N5286_NNNNA)
15- 18 I4 K Teff Effective temperature
20- 23 F4.2 [cm/s2] logg Surface gravity
25- 28 F4.2 km/s vt ? Microturbulent velocity
30- 34 F5.2 [-] [Fe/H] Metallicity
36- 39 F4.2 [-] e_[Fe/H] rms uncertainty on [Fe/H]
41- 44 F4.2 [-] [O/Fe] ?=- [O/Fe] abundance
46- 50 F5.2 [-] [Na/Fe]N ?=- NLTE [Na/Fe] abundance
52- 55 F4.2 [-] e_[Na/Fe]N ?=- rms uncertainty on [Na/Fe]N (1)
57- 61 F5.2 [-] [Na/Fe]L ?=- LTE [Na/Fe] abundance
63- 66 F4.2 [-] e_[Na/Fe]L ?=- rms uncertainty on [Na/Fe]L (1)
68- 71 F4.2 [-] [Si/Fe] ?=- [Si/Fe] abundance
73- 76 F4.2 [-] e_[Si/Fe] ?=- rms uncertainty on [Si/Fe] (1)
78- 81 F4.2 [-] [Ca/Fe] ?=- [Ca/Fe] abundance
83- 86 F4.2 [-] e_[Ca/Fe] ?=- rms uncertainty on [Ca/Fe] (1)
88- 92 F5.2 [-] [Sc/Fe] ?=- [Sc/Fe] abundance
94- 97 F4.2 [-] e_[Sc/Fe] ?=- rms uncertainty on [Sc/Fe] (1)
99-102 F4.2 [-] [Ti/Fe] ?=- [Ti/Fe] abundance
104-107 F4.2 [-] [Ni/Fe] ?=- [Ni/Fe] abundance
109-112 F4.2 [-] e_[Ni/Fe] ?=- rms uncertainty on [Ni/Fe] (1)
114-118 F5.2 [-] [Ba/Fe] ?=- [Ba/Fe] abundance
120-123 F4.2 [-] [La/Fe] ?=- [La/Fe] abundance
125-128 F4.2 [-] e_[La/Fe] ?=- rms uncertainty on [La/Fe] (1)
130-135 A6 --- Group Status of s-rich or s-poor
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Note (1): Line-to-line scatter is listed when more than one line has been
analysed.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Jan-2016