J/A+A/576/A113 Abundances of solar neighbourhood stars (Zenoviene+, 2015)
Stellar substructures in the solar neighbourhood.
IV. Kinematic Group 1 in the Geneva-Copenhagen survey.
Zenoviene R., Tautvaisiene G., Nordstroem B., Stonkute E., Barisevicius G.
<Astron. Astrophys., 576, A113-113 (2015)>
=2015A&A...576A.113Z 2015A&A...576A.113Z
ADC_Keywords: Stars, nearby ; Abundances
Keywords: stars: abundances - Galaxy: disk - Galaxy: formation -
Galaxy: evolution
Abstract:
A combined study of kinematics and chemical composition of stars is
one of the most promising tools of research in Galaxy formation. The
main goal in this field of research is to reconstruct the formation
history of our Galaxy, to reveal the origin of the thick disc, and to
find remnants of ancient mergers. We determine detailed elemental
abundances in stars belonging to the so-called Group 1 of the
Geneva-Copenhagen survey (GCS) and compare the chemical composition
with the Galactic thin- and thick-disc stars, with the GCS Group 2 and
Group 3 stars, as well as with several kinematic streams of similar
metallicities. The aim is to search for chemical signatures that might
give information about the formation history of this kinematic group
of stars. High-resolution spectra were obtained with the Fibre-fed
Echelle Spectrograph spectrograph at the Nordic Optical Telescope, La
Palma, and were analysed with a differential model atmosphere method.
Comparison stars were observed and analysed with the same method. The
average value of [Fe/H] for the 37 stars of Group 1 is
-0.20±0.14dex. Investigated Group 1 stars can be separated into
three age subgroups. Along with the main 8- and 12-Gyr-old
populations, a subgroup of stars younger than 5Gyr can be separated as
well. Abundances of oxygen, α-elements, and r-process dominated
elements are higher than in Galactic thin-disc dwarfs. This elemental
abundance pattern has similar characteristics to that of the Galactic
thick disc and differs slightly from those in Hercules, Arcturus, and
AF06 stellar streams. The similar chemical composition of stars in
Group 1, as well as in Group 2 and 3, with that in stars of the thick
disc might suggest that their formation histories are linked. The
chemical composition pattern together with the kinematic properties
and ages of stars in the investigated GCS groups provide evidence of
their common origin and possible relation to an ancient merging event.
A gas-rich satellite merger scenario is proposed as the most likely
origin.
Description:
We obtained high-resolution spectra of the programme and comparison
stars with the Fibre-fed Echelle Spectrograph on the Nordic Optical
2.5 m telescope (NOT) during 2008, 2011, and 2012.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 231 50 Main atmospheric parameters and elemental
abundances of programme and comparison stars
table5.dat 150 50 Elemental abundances of neutron-capture
elements for programme and comparison stars
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See also:
V/130 : Geneva-Copenhagen Survey of Solar neighbourhood III (Holmberg+, 2009)
J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Group Group (G1)
18- 27 A10 --- Star Star name
29- 32 I4 K Teff Effective temperature
34- 36 F3.1 [cm/s2] logg Surface gravity
38- 40 F3.1 km/s vt Microturbulent velocity
42- 46 F5.2 [Sun] [Fe/H] Metallicity
48- 51 F4.2 [Sun] s1 rms on [FeI/H] σ(FeI)
53- 54 I2 --- n1 Number of lines for FeI
56- 59 F4.2 [Sun] s2 rms on [FeII/H] σ(FeII)
61 I1 --- n2 Number of lines for FeII
63- 67 F5.2 [Sun] [O/Fe] ?=- [O/Fe] abundance
69- 73 F5.2 [Sun] [Na/Fe] ?=- [Na/Fe] abundance
75- 78 F4.2 [Sun] e_[Na/Fe] ?=- rms uncertainty on [Na/Fe]
80 I1 --- o_[Na/Fe] ?=- Number of lines for Na
82- 86 F5.2 [Sun] [Mg/Fe] ?=- [Mg/Fe] abundance
88- 91 F4.2 [Sun] e_[Mg/Fe] ?=- rms uncertainty on [Mg/Fe]
93 I1 --- o_[Mg/Fe] ?=- Number of lines for Mg
95- 99 F5.2 [Sun] [Al/Fe] ?=- [Al/Fe] abundance
101-104 F4.2 [Sun] e_[Al/Fe] ?=- rms uncertainty on [Al/Fe]
106 I1 --- o_[Al/Fe] ?=- Number of line for Al
108-112 F5.2 [Sun] [Si/Fe] ?=- [Si/Fe] abundance
114-117 F4.2 [Sun] e_[Si/Fe] ?=- rms uncertainty on [Si/Fe]
119-120 I2 --- o_[Si/Fe] ?=- Number of line for Si
122-126 F5.2 [Sun] [Ca/Fe] ?=- [Ca/Fe] abundance
128-131 F4.2 [Sun] e_[Ca/Fe] ?=- rms uncertainty on [Ca/Fe]
133-134 I2 --- o_[Ca/Fe] ?=- Number of line for Ca
136-140 F5.2 [Sun] [Sc/Fe] ?=- [Sc/Fe] abundance
142-145 F4.2 [Sun] e_[Sc/Fe] ?=- rms uncertainty on [Sc/Fe]
147-148 I2 --- o_[Sc/Fe] ?=- Number of line for Sc
150-154 F5.2 [Sun] [TiI/Fe] ?=- [TiI/Fe] abundance
156-159 F4.2 [Sun] e_[TiI/Fe] ?=- rms uncertainty on [TiI/Fe]
161-162 I2 --- o_[TiI/Fe] ?=- Number of line for TiI
164-168 F5.2 [Sun] [TiII/Fe] ?=- [TiII/Fe] abundance
170-173 F4.2 [Sun] e_[TiII/Fe] ?=- rms uncertainty on [TiII/Fe]
175 I1 --- o_[TiII/Fe] ?=- Number of line for TiII
177-181 F5.2 [Sun] [V/Fe] ?=- [V/Fe] abundance
183-186 F4.2 [Sun] e_[V/Fe] ?=- rms uncertainty on [V/Fe]
188-189 I2 --- o_[V/Fe] ?=- Number of line for V
191-195 F5.2 [Sun] [Cr/Fe] ?=- [Cr/Fe] abundance
197-200 F4.2 [Sun] e_[Cr/Fe] ?=- rms uncertainty on [Cr/Fe]
202-203 I2 --- o_[Cr/Fe] ?=- Number of line for Cr
205-209 F5.2 [Sun] [Co/Fe] ?=- [Co/Fe] abundance
211-214 F4.2 [Sun] e_[Co/Fe] ?=- rms uncertainty on [Co/Fe]
216-217 I2 --- o_[Co/Fe] ?=- Number of line for Co
219-223 F5.2 [Sun] [Ni/Fe] ?=- [Ni/Fe] abundance
225-228 F4.2 [Sun] e_[Ni/Fe] ?=- rms uncertainty on [Ni/Fe]
230-231 I2 --- o_[Ni/Fe] ?=- Number of line for Ni
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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- 16 A16 --- Group Group (G1)
18- 27 A10 --- Star Star name
29- 33 F5.2 [Sun] [Y/Fe] ?=- [Y/Fe] abundance
35- 38 F4.2 [Sun] e_[Y/Fe] ?=- rms uncertainty on [Y/Fe]
40 I1 --- o_[Y/Fe] ?=- Number of lines for Y
42- 46 F5.2 [Sun] [ZrI/Fe] ?=- [ZrI/Fe] abundance
48- 51 F4.2 [Sun] e_[ZrI/Fe] ?=- rms uncertainty on [ZrI/Fe]
53 I1 --- o_[ZrI/Fe] ?=- Number of lines for ZrI
55- 59 F5.2 [Sun] [ZrII/Fe] ?=- [ZrII/Fe] abundance
61- 64 F4.2 [Sun] e_[ZrII/Fe] ?=- rms uncertainty on [ZrII/Fe]
66 I1 --- o_[ZrII/Fe] ?=- Number of line for ZrII
68- 72 F5.2 [Sun] [Ba/Fe] ?=- [Ba/Fe] abundance
74- 78 F5.2 [Sun] [La/Fe] ?=- [La/Fe] abundance
80- 83 F4.2 [Sun] e_[La/Fe] ?=- rms uncertainty on [La/Fe]
85 I1 --- o_[La/Fe] ?=- Number of line for La
87- 91 F5.2 [Sun] [Ce/Fe] ?=- [Ce/Fe] abundance
93- 96 F4.2 [Sun] e_[Ce/Fe] ?=- rms uncertainty on [Ce/Fe]
98 I1 --- o_[Ce/Fe] ?=- Number of line for Ce
100-104 F5.2 [Sun] [Pr/Fe] ?=- [Pr/Fe] abundance
106-109 F4.2 [Sun] e_[Pr/Fe] ?=- rms uncertainty on [Pr/Fe]
111 I1 --- o_[Pr/Fe] ?=- Number of line for Pr
113-117 F5.2 [Sun] [Nd/Fe] ?=- [Nd/Fe] abundance
119-122 F4.2 [Sun] e_[Nd/Fe] ?=- rms uncertainty on [Nd/Fe]
124 I1 --- o_[Nd/Fe] ?=- Number of line for Nd
126-130 F5.2 [Sun] [Sm/Fe] ?=- [Sm/Fe] abundance
132-135 F4.2 [Sun] e_[Sm/Fe] ?=- rms uncertainty on [Sm/Fe]
137 I1 --- o_[Sm/Fe] ?=- Number of line for Sm
139-143 F5.2 [Sun] [Eu/Fe] ?=- [Eu/Fe] abundance
145-148 F4.2 [Sun] e_[Eu/Fe] ?=- rms uncertainty on [Eu/Fe]
150 I1 --- o_[Eu/Fe] ?=- Number of line for Eu
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Global Notes:
Note (G1): the groups are:
Group 1 = group #1 as defined by Helmi et al. (2006MNRAS.365.1309H 2006MNRAS.365.1309H): 37 stars
Thick-disc = kinematical group of the thick disc stars: 5 stars
Thin-disc = kinematical group of the thin disc stars: 8 stars
History:
From electronic version of the journal
References:
Stonkute et al., Paper I 2012A&A...541A.157S 2012A&A...541A.157S
Stonkute et al., Paper II 2013A&A...555A...6S 2013A&A...555A...6S
Zenoviene et al., Paper III 2014A&A...563A..53Z 2014A&A...563A..53Z
(End) Patricia Vannier [CDS] 01-Jun-2015