J/MNRAS/485/4375 UMa Moving Group chronochemokinematic analysis (Dopcke+, 2019)
The Ursa Major Moving Group: a chronochemokinematic analysis.
Dopcke G., Porto de Mello G.F., Sneden C.
<Mon. Not. R. Astron. Soc., 485, 4375-4388 (2019)>
=2019MNRAS.485.4375D 2019MNRAS.485.4375D (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Effective temperatures ; Spectra, optical ;
Stars, ages ; Space velocities ; Photometry, UBVRI ;
Photometry, uvby
Keywords: techniques: spectroscopic, stars: abundances
Abstract:
Stars in kinematic groups are believed to share the same age,
metallicity, and velocity vectors, and are disrupted by events such as
encounters with massive objects, leaving a residue of stars sharing
the same kinematic properties, thus bridging an important evolutionary
gap between clusters and field stars. We determine the most likely
metallicity for the unevolved stars of the group, collectively, by
assuming that these stars all conform to a single zero-age main
sequence line and requiring that residual Teff and luminosity values
be minimized: the [Fe/H] value that best describes the observed HR
diagram of the group lies in the range +0.05<[Fe/H]<+0.10. In this
work, we report the detailed spectroscopic analysis of 23 stars in the
Ursa Major Group (UMaG), together with seven young field stars that
function as a control sample, based on high S/N, R∼60000 optical
spectra. We present abundances for C, Na, Al, Si, Ca, Sc, Ti, V, Cr,
Mn, Co, Fe, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Gd, and Eu. We
also found that there is a clear kinematic nucleus in the UVW space,
but from the spectroscopic analysis only a fraction of these stars
could be considered chemically and chronologically homogeneous. The
results suggest that the UMaG has physical existence in a
chronochemokinematic sense, but is not chemically peculiar: high Ba
abundance seems to be a common feature of young stars. From the
initial sample, only 14 (61 per cent) stars were finally considered
members of the UMaG, resulting in an average metallicity and standard
deviation of [Fe/H]=0.01 and 0.07, respectively, consistent with
previous works. We finally conclude that even though the UMaG stars
share a common kinematics, age, and metallicity, they do not have the
same chemical abundance pattern, pointing to a dynamical origin of the
Group.
Description:
Our sample consists of 23 UMaG stars that had membership assignment in
the literature, and seven young stars for comparison. Such young stars
have chromospheric activity logR'HK>-4.44 (Noyes et al.
1984ApJ...279..763N 1984ApJ...279..763N). This implies that the stars are young, not older
than the Hyades (635Myr; Cummings et al. 2017AJ....153..128C 2017AJ....153..128C). We also
obtained a spectrum of Ganymede, under the same conditions as the
stellar spectra, to use it as a solar proxy.
The stellar spectra we analysed here were obtained between 1999 27th
February and 1st March, at the McDonald Observatory, using a 2.7m
telescope, and the Tull coude Echelle spectrograph (Tull et al.
1995PASP..107..251T 1995PASP..107..251T). The spectra have R=60000 and S/N>150 for all
spectra, and >300 in most cases, with wavelength coverage from 4500 to
6800Å.
The Paschen slope in the type K, G, and F stars, studied here, is
sensitive to Teff changes, so we used the colours (B-V) Johnson,
(BT-VT) Tycho, and (b-y) Stromgren, which are good indicators of
this slope.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 35 37 Group membership classification according to the
results from King et al. (2003AJ....125.1980K 2003AJ....125.1980K)
table2.dat 46 25 Luminosities, Teff, and parallaxes used for the
photometric analysis
table3.dat 61 31 Atmospheric parameters for the sample
table5.dat 59 37 Space Galactic Velocities (U, V, W) and
radial velocity (RV) for the sample
table6.dat 33 20 The kinematic nucleus of the UMaG
table7.dat 41 21 Results of the evolutionary and nucleosynthetic
analyses
table8.dat 54 14 Final nucleus for the UMaG with chronological,
chemical, and kinematic identity
table9.dat 73 10 Comparison of stellar parameter
table10.dat 95 2 Comparison of abundances
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name (HD NNNNNN)
11- 15 A5 --- Member Likelihood of belonging to the group according
to the results from King et al.
(2003AJ....125.1980K 2003AJ....125.1980K) (1)
17- 21 F5.3 mag B-V B-V colour index (2)
23- 27 F5.3 mag b-y ? b-y coulour index
29 A1 --- r_b-y References for b-y (3)
31- 35 F5.3 mag BT-VT ? BT-VT colour index (2)
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Note (1): Likelihood of membership as follows:
Y = certain membership
Y? = probable
? = uncertain
N? = probable non-member
Field = young field stars used as a control sample
Note (2): (B-V) and (BT-VT) colour indices are from Perryman & ESA
(Perryman M.A.C., ESA , 1997 , The HIPPARCOS and TYCHO catalogues.
ESA SP-1200., Cat. I/239), except for HD 109647 in which case they
are from Mermilliod (1986BICDS..31..185M 1986BICDS..31..185M)
Note (3): References as follows:
G = Olsen (1993A&AS..102...89O 1993A&AS..102...89O)
F = Olsen (1983A&AS...54...55O 1983A&AS...54...55O)
1 = Fabregat & Reglero (1990A&AS...82..531F 1990A&AS...82..531F)
2 = Crawford et al. (1966AJ.....71..709C 1966AJ.....71..709C),
Crawford & Barnes (1969AJ.....74..407C 1969AJ.....74..407C), and
Crawford & Barnes (1993PASP..105...36S 1993PASP..105...36S)
3 = Sowell & Wilson (1993PASP..105...36S 1993PASP..105...36S)
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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- 9 A9 --- Name Star name (HD NNNNNN)
11- 14 I4 K Teff Effective temperature (1)
16- 19 I4 K e_Teff Error on Teff
21- 26 F6.3 [Lsun] logL log of stellar luminosity (2)
28- 32 F5.3 [Lsun] e_logL Error on logL (3)
34- 40 F7.3 mas plx Parallax
42- 46 F5.3 mas e_plx Error on plx
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Note (1): We calculated the Teff from a weighted average of the Tphot(B-V),
Tphot(BT-VT), and Tphot(b-y)
Note (2): The bolometric correction (Cbol) and luminosity (logL), were
calculated following Flower (1996ApJ...469..355F 1996ApJ...469..355F):
Cbol=-25.85+0.014Teff-3.18x10-6(Teff)2+3.12x10-10(Teff)3
-1.17x(Teff)4,
logL=-0.4x(MV+Cbol-4.75)
where MV is the visual magnitude from Hipparcos
Note (3): The uncertainty on logL, is calculated as:
σ(logL)=-0.4xσ(MV) , where σ(MV) is the
uncertainty on the visual magnitude from Hipparcos
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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- 10 A10 --- Name Star name (HD NNNNNNA)
12- 13 A2 --- n_Name Note on Name (1)
15- 18 I4 K Teffsp Spectral effective temperature
20- 23 I4 K Teffph Photomeric effective temperature
25- 27 F3.1 [cm/s2] logg Surface gravity
29- 31 F3.1 km/s vt Microturbulent velocity
33- 37 F5.2 [-] [Fe/H] Iron to hydrogen abundance ratio
39- 42 F4.2 [-] sigFeI Dispersion on the abundance values obtained
from the FeI line
44- 47 F4.2 [-] sigFeII Dispersion on the abundance values obtained
from the FeII line
49- 50 I2 --- nlFeI Number of FeI lines used to obtain all
parameters
52- 53 I2 --- nlFeII Number of FeII lines used to obtain all
parameters
55- 57 F3.1 0.1nm FWHM Mean full width at half-maximum of the
spectra
59- 61 I3 --- S/N Mean signal to noise ratio
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Note (1): The star HD 26913 was observed during the first and the second night,
which are indicated with the suffix N1 and N2, respectively.
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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- 9 A9 --- Name Star name (HD NNNNNN)
11- 15 F5.1 km/s U U component of space galactic velocity
17- 19 F3.1 km/s e_U Error on U
21- 25 F5.1 km/s V V component of space galactic velocity
27- 29 F3.1 km/s e_V Error on V
31- 35 F5.1 km/s W W component of space galactic velocity
37- 39 F3.1 km/s e_W Error on W
41- 45 F5.1 km/s RV Radial velocity
47- 49 F3.1 km/s e_RV Error on RV
51- 59 A9 --- Notes Source of the coordinates and proper motions
used to compute the velocities (1)
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Note (1): The values for right ascension, declination, proper motion, and their
errors were obtained from Gaia Collaboration (2018A&A...616A...1G 2018A&A...616A...1G),
in most of the cases. When the uncertainties associated with Gaia data
surpassed 5 times the one for the other sources we used the latter.
Other sources as follows:
King = King et al. 2003AJ....125.1980K 2003AJ....125.1980K
Hipparcos = Perryman M.A.C., ESA, 1997, The HIPPARCOS and TYCHO catalogues.
ESA SP-1200
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Star name (HD NNNNNN)
11- 15 F5.2 [-] [Fe/H] Iron to hydrogen abundance ratio
17- 24 A8 --- SM93 Star abundance membership according to
Soderblom & Mayor (1993AJ....105..226S 1993AJ....105..226S)
26- 27 A2 --- KKin Star abundance membership from King kinematics
membership (King et al. 2003AJ....125.1980K 2003AJ....125.1980K) (1)
29- 30 A2 --- KSpec Star abundance membership from King spectroscopic
membership (King et al. 2003AJ....125.1980K 2003AJ....125.1980K) (1)
32- 34 A3 --- KFinal Star abundance membership from King Final
membership (King et al. 2003AJ....125.1980K 2003AJ....125.1980K) (1)
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Note (1): Likelihood of membership as follows:
Y = certain membership
Y? = probable
? = uncertain
N? = probable non-member
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Star name (HD NNNNNN)
11- 15 F5.2 [-] [Fe/H] Iron to hydrogen abundance ratio
17 A1 --- f_[Fe/H] Flag on [Fe/H] (1)
19 I1 --- kgroup k-group from the k-means analysis (G1)
21- 30 A10 --- Age Star age (G2)
32- 39 A8 [-] logRHK Logarithm of R'HK chromospheric activity
index (G3)
41 I1 --- r_logRHK References for logRHK (2)
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Note (1): Flag as follows:
* = For HD 13959, we used the Tphoteff to reobtain its [Fe/H]
Note (2): References as follows:
1 = King et al. (2003AJ....125.1980K 2003AJ....125.1980K)
2 = Soderblom & Mayor (1993AJ....105..226S 1993AJ....105..226S)
3 = Wright et al. (2004yCat..21520261W 2004yCat..21520261W)
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Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name Star name (HD NNNNNN)
11- 14 F4.1 km/s U U component of space galactic velocity
16- 18 F3.1 km/s e_U Error on U
20- 24 F5.1 km/s V V component of space galactic velocity
26- 28 F3.1 km/s e_V Error on V
30- 34 F5.2 [-] [Fe/H] Iron to hydrogen abundance ratio
36 I1 --- kgroup k-group from the k-means analysis (G1)
38- 47 A10 --- Age Star age (G2)
49- 55 A7 --- logRHK Logarithm of R'HK chromospheric activity
index (G3)
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Byte-by-byte Description of file: table9.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Star name (HD NNNNNNA)
12- 15 I4 K T Effective temperature (this work)
17- 20 I4 K TAG ? Effective temperature from Ammler-von Eiff &
Guenther (2009A&A...508..677A 2009A&A...508..677A)
22- 25 I4 K TB ? Effective temperature from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
27- 30 I4 K TT ? Effective temperature from Tabernero et al.
(2017A&A...597A..33T 2017A&A...597A..33T)
32- 35 F4.2 [cm/s2] logg Surface gravity (this work)
37- 40 F4.2 [cm/s2] loggAG ? Surface gravity from Ammler-von Eiff &
Guenther (2009A&A...508..677A 2009A&A...508..677A)
42- 45 F4.2 [cm/s2] loggB ? Surface gravity from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
47- 50 F4.2 [cm/s2] loggT ? Surface gravity from Tabernero et al.
(2017A&A...597A..33T 2017A&A...597A..33T)
52- 56 F5.2 [-] [Fe/H] Iron to hydrogen abundance ratio (this work)
58- 62 F5.2 [-] [Fe/H]AG ? Iron to hydrogen abundance ratio from
Ammler-von Eiff & Guenther
(2009A&A...508..677A 2009A&A...508..677A)
64- 67 F4.2 [-] [Fe/H]B ? Iron to hydrogen abundance ratio from
Biazzo et al. (2012MNRAS.427.2905B 2012MNRAS.427.2905B)
69- 73 F5.2 [-] [Fe/H]T ? Iron to hydrogen abundance ratio from
Tabernero et al. (2017A&A...597A..33T 2017A&A...597A..33T)
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Star name (HD NNNNN)
10- 14 F5.2 [-] [Na/Fe] Na to iron abundance ratio (this work)
16- 20 F5.2 [-] [Al/Fe] Al to iron abundance ratio (this work)
22- 25 F4.2 [-] [Ti/Fe] Ti to iron abundance ratio (this work)
27- 31 F5.2 [-] [Cr/Fe] Cr to iron abundance ratio (this work)
33- 37 F5.2 [-] [Ni/Fe] Ni to iron abundance ratio (this work)
39- 43 F5.2 [-] [Na/Fe]B Na to iron abundance ratio from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
45- 48 F4.2 [-] [Al/Fe]B Al to iron abundance ratio from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
50- 54 F5.2 [-] [Ti/Fe]B Ti to iron abundance ratio from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
56- 60 F5.2 [-] [Cr/Fe]B Cr to iron abundance ratio from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
62- 66 F5.2 [-] [Ni/Fe]B Ni to iron abundance ratio from Biazzo et al.
(2012MNRAS.427.2905B 2012MNRAS.427.2905B)
68- 72 F5.2 [-] [Na/Fe]T Na to iron abundance ratio from
Tabernero et al. (2017A&A...597A..33T 2017A&A...597A..33T)
74- 78 F5.2 [-] [Al/Fe]T Al to iron abundance ratio from
Tabernero et al. (2017A&A...597A..33T 2017A&A...597A..33T)
80- 83 F4.2 [-] [Ti/Fe]T Ti to iron abundance ratio from
Tabernero et al. (2017A&A...597A..33T 2017A&A...597A..33T)
85- 89 F5.2 [-] [Cr/Fe]T Cr to iron abundance ratio from
Tabernero et al. (2017A&A...597A..33T 2017A&A...597A..33T)
91- 95 F5.2 [-] [Ni/Fe]T Ni to iron abundance ratio from
Tabernero et al. (2017A&A...597A..33T 2017A&A...597A..33T)
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Global notes:
Note (G1): We applied the k-means clustering algorithm to find groups of stars
that share a common nucleosynthesis history. The minimum for the
total within-cluster sum of squares was k=4. Thus it leads us to
define four groups (hereafter k-group), within the k-means analysis.
k-group 1 (9 members), 2 (15 members), and 3 (5 members) have lower
dispersion in the parameters and are more reliable. k-group 4, with
only 2 members (HD 45088 and HD 72905), had been separated from the
others by having very uncertain values in the r-process and the
light s-process abundances, so its real existence is doubtful.
Note (G2): The stars closer to the zero-age main sequence (ZAMS) than twice
their uncertainties (in luminosity and Teff) were classified as
'ZAMS'. The stars above or below this interval are also marked.
When given, the age is in Gyrs.
Note (G3): To compare our results with other age-related observables, we
searched the literature for the chromospheric activity index logRHK
for the stars in the kinematic group. The giant stars do not have
logRHK index, since it cannot be applied to determine the age of
this stellar type.
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History:
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(End) Ana Fiallos [CDS] 29-Sep-2022