J/ApJ/833/225 -2.6≤[Fe/H]≤0.2 F and G dwarfs. II. Abundances (Zhao+, 2016)
Systematic non-LTE study of the -2.6≤[Fe/H]≤0.2 F and G dwarfs in the solar
neighborhood.
II. Abundance patterns from Li to Eu.
Zhao G., Mashonkina L., Yan H.L., Alexeeva S., Kobayashi C., Pakhomov Y.,
Shi J.R., Sitnova T., Tan K.F., Zhang H.W., Zhang J.B., Zhou Z.M.,
Bolte M., Chen Y.Q., Li X., Liu F., Zhai M.
<Astrophys. J., 833, 225-225 (2016)>
=2016ApJ...833..225Z 2016ApJ...833..225Z (SIMBAD/NED BibCode)
ADC_Keywords: Stars, dwarfs ; Abundances ; Spectroscopy
Keywords: Galaxy: evolution; line: formation; stars: abundances;
stars: atmospheres; stars: late-type
Abstract:
For the first time, we present an extensive study of stars with
individual non-LTE (NLTE) abundances for 17 chemical elements from Li
to Eu in a sample of stars uniformly distributed over the
-2.62≤[Fe/H]≤+0.24 metallicity range that is suitable for the
Galactic chemical evolution research. The star sample has been
kinematically selected to trace the Galactic thin and thick disks and
halo. We find new results and improve earlier ones as follows: (i) the
element-to-iron ratios for Mg, Si, Ca, and Ti form a metal-poor (MP)
plateau at a similar height of 0.3 dex, and the knee occurs at common
[Fe/H]~-0.8. The knee at the same metallicity is observed for [O/Fe],
and the MP plateau is formed at [O/Fe]=0.61. (ii) The upward trend of
[C/O] with decreasing metallicity exists at [Fe/H]←1.2, supporting
the earlier finding of Akerman et al. (iii) An underabundance of Na
relative to Mg in the [Fe/H]←1 stars is nearly constant, with the
mean [Na/Mg]~-0.5. (iv) The K/Sc, Ca/Sc, and Ti/Sc ratios form
well-defined trends, suggesting a common site of the K-Ti production.
(v) Sr follows the Fe abundance down to [Fe/H]~-2.5, while Zr is
enhanced in MP stars. (vi) The comparisons of our results with some
widely used Galactic evolution models are given. The use of the NLTE
element abundances gives increased credit to the interpretation of the
data in the context of the chemical evolution of the Galaxy.
Description:
Our stellar sample, the observed stellar spectra, and the
determination of atmospheric parameters were presented in Paper I
(Sitnova+, 2015ApJ...808..148S 2015ApJ...808..148S).
Spectra of 48 stars were obtained for our project using the Hamilton
Echelle Spectrograph mounted on the Shane 3m telescope of the Lick
Observatory. Their resolving power is R∼60000, the spectral coverage
is 3700-9300Å. For two stars their spectra were obtained with
CFHT/ESPaDOnS, as described in Paper I. The high-quality observed
spectrum of HD 140283 was taken from the ESO UVESPOP survey (Bagnulo+
2003Msngr.114...10B 2003Msngr.114...10B).
For some stars our observational material was complemented with the
data from our earlier projects, namely, VLT2/UVES, 67.D-0086A
(HD74000, BD-04°3208), and 2.2m/FOCES (HD59374, HD59984, HD103095,
HD134169). We also employed the archives of CFHT/ESPaDOnS10 for
BD-13°3442, VLT2/UVES, and 3.6m/HARPS11 for HD59374
(074.C-0364(A), R∼115000), HD59984 (076.B-0133(A), R∼57000), HD100563
(R∼115000), and HD108177 (R∼115000), as well as 1.93m/SOPHIE12
(R=76500) and 1.93m/ELODIE13 (R=42000) for HD64090 and BD+66°0268.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
stars.dat 41 51 List of objects from table 3; table added by CDS
table3.dat 87 1020 Summary of the obtained stellar abundances
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See also:
J/MNRAS/456/1221 : FGK dwarfs atmospheric parameters (Ryabchikova+, 2016)
J/ApJ/817/53 : Fe abundance analysis in HD84937 (Sneden+, 2016)
J/A+A/585/A102 : Copper abundances in solar neighborhood stars (Yan+, 2016)
J/A+A/584/A86 : Abundance analysis of HD 140283 (Siqueira-Mello+, 2015)
J/AZh/92/834 : A list of tantalum lines (Pakhomov, 2015)
J/A+A/572/A103 : Inelastic silicon-hydrogen collision data (Belyaev+, 2014)
J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)
J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)
J/AJ/146/97 : Ti lines for the Lick hallow-cathode lamp (Pakhomov+, 2013)
J/ApJ/771/67 : Abundances for 97 metal-poor stars. II. (Ishigaki+, 2013)
J/A+A/552/A128 : Abundances of neutron-capture elements (Mishenina+, 2013
J/ApJ/756/46 : Lithium abundances in HIP stars (Ramirez+, 2012)
J/A+A/545/A32 : Chemical abundances of 1111 FGK stars (Adibekyan+, 2012)
J/A+A/541/A143 : NLTE Corrections of the Ca lines (Spite+, 2012)
J/MNRAS/403/1413 : Updated stellar yields from AGB models (Karakas, 2010)
J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)
J/A+A/503/541 : Li in late-type stars non-LTE calculations (Lind+, 2009)
J/AZh/84/997 : Abundances of Sr, Y, Zr, Ce and Ba (Mashonkina+, 2007)
J/A+A/469/1203 : IRON project LXIV (Melendez+, 2007)
J/A+A/442/961 : Li content of the Galactic Halo stars (Charbonnel+, 2005)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/A+A/433/185 : Abundance analysis of 102 F and G dwarfs (Bensby+, 2005)
J/A+A/420/183 : Spectro. survey in solar neighborhood (Allende Prieto+ 2004)
J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)
J/MNRAS/340/304 : [X/Fe] of Galactic disc F and G dwarfs (Reddy+, 2003)
J/A+AS/142/467 : Broadening of metallic lines by H collisions (Barklem+ 2000)
J/A+A/326/751 : Chemical composition of halo and disk stars (Nissen+, 1997)
J/A+A/275/101 : Chemical evol. of the galactic disk I. (Edvardsson+ 1993)
Byte-by-byte Description of file: stars.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Object, Simbad name
12- 15 I4 K Teff [4810/6600] Object effective temperature,
derived (1)
17- 20 F4.2 cm/s2 logg [3/4.8] Object surface gravity, derived (1)
22- 26 F5.2 [Sun] [Fe/H] [-2.7/0.3] Object metallicity, derived (1)
28- 30 F3.1 km/s xi [0.6/2] Microturbulence velocity, derived (1)
32- 41 A10 --- Pop Object Galactic population (Halo, Thick disk
or Thin disk)
--------------------------------------------------------------------------------
Note (1): Stellar atmosphere parameters from Paper I
(Sitnova+ 2015ApJ...808..148S 2015ApJ...808..148S).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name Object, Simbad name
12- 15 I4 K Teff [4810/6600] Object effective temperature,
derived (1)
17- 20 F4.2 cm/s2 logg [3/4.8] Object surface gravity, derived (1)
22- 26 F5.2 [Sun] [Fe/H] [-2.7/0.3] Object metallicity, derived (1)
28- 30 F3.1 km/s xi [0.6/2] Microturbulence velocity, derived (1)
32- 41 A10 --- Pop Object Galactic population (Halo, Thick disk
or Thin disk)
43- 44 I2 --- Z [3/63]? Atomic number
46- 50 A5 --- Species Chemical species investigated
52- 53 I2 --- N [0/29]? Number of lines fit
55- 59 F5.2 [Sun] [X/H]LTE [-3.6/2.8]? Abundance, relative to hydrogen,
LTE case
61- 64 F4.2 [Sun] e_[X/H]LTE [0/0.3]? Uncertainty in [X/H]LTE
66- 70 F5.2 [Sun] [X/Fe]LTE [-1.1/0.7]? Abundance, relative to iron,
LTE case
72- 76 F5.2 [Sun] [X/H]NLTE [-3.3/2.7]? Abundance, relative to hydrogen,
NLTE case
78- 81 F4.2 [Sun] e_[X/H]NLTE [0/0.3]? Uncertainty in [X/H]NLTE
83- 87 F5.2 [Sun] [X/Fe]NLTE [-0.8/0.7]? Abundance, relative to iron,
NLTE case
--------------------------------------------------------------------------------
Note (1): Stellar atmosphere parameters from Paper I
(Sitnova+ 2015ApJ...808..148S 2015ApJ...808..148S).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Sitnova et al. Paper I. 2015ApJ...808..148S 2015ApJ...808..148S
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-May-2017