J/A+A/440/321 Chemical abundances in 43 metal-poor stars (Jonsell+, 2005)
Chemical abundances in 43 metal-poor stars.
Jonsell K., Edvardsson B., Gustafsson B., Magain P., Nissen P.E., Asplund M.
<Astron. Astrophys. 440, 321 (2005)>
=2005A&A...440..321J 2005A&A...440..321J
ADC_Keywords: Stars, population II ; Abundances, peculiar ; Space velocities ;
Photometry, uvby ; Equivalent widths
Keywords: stars: Population II - stars: fundamental parameters -
stars: abundances - Galaxy: halo - Galaxy: abundances -
Galaxy: evolution
Abstract:
We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V,
Cr, Fe, Ni and Ba for 43 metal-poor field stars in the solar
neighbourhood, most of them subgiants or turn-off-point stars, with
iron abundances [Fe/H] ranging from -0.4 to -3.0. About half of this
sample has not been analysed spectroscopically in detail before.
Effective temperatures were estimated from uvby photometry, and
surface gravities primarily from Hipparcos parallaxes. The analysis is
differential relative to the Sun, and carried out with plane-parallel
MARCS models.
Various sources of error are discussed and found to contribute a
total error of about 0.1-0.2dex for most elements, while relative
abundances, such as [Ca/Fe], are most probably more accurate. For the
oxygen abundances, determined in an NLTE analysis of the 7774Å
triplet lines, the errors may be somewhat larger.
Description:
Data from an analysis of 43 metal-poor field stars with iron
abundances [Fe/H] ranging from -0.4 to -3.0dex are presented here.
Photometric data, stellar velocities, masses, fundamental parameters,
spectral classifications and notations of possible binarity are
given. Tables with line data for O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr,
Fe, Ni and Ba, equivalent widths and resulting abundances are also
given.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 31 1727 Equivalent widths
table2.dat 101 43 Stellar data
table3.dat 72 62 Atomic line data and solar abundances
table4.dat 102 43 Chemical abundances
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HD HD identification number
8- 9 A2 --- Elem Element abbreviation
11- 12 I2 --- Z Atomic number
14 I1 --- Stage [1/2] Ionization stage:
1: neutral, 2: singly ionized
16- 23 F8.3 0.1nm Lambda Air wavelength in Angstrom
26- 30 F5.1 0.1pm EW Equivalent width
31 A1 --- u_EW Uncertainty flag on EW
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HD HD identification number
8- 12 F5.3 mag Vmag Visual apparent magnitude
14- 18 F5.3 mag (b-y) Stromgren colour index
20- 24 F5.3 mag c1 Stromgren Balmer discontinuity index
26- 30 A5 --- r_(b-y) References for Stromgren photometry (1)
32- 35 I4 km/s UVel Stellar U velocity relative to the LSR (2)
37- 40 I4 km/s VVel Stellar V velocity relative to the LSR
42- 45 I4 km/s WVel Stellar W velocity relative to the LSR
47- 50 F4.2 solMass Mass Stellar mass derived from evolutionary tracks
52 I1 --- Model [1/2] Reference for Evolutionary tracks (3)
53 I1 --- r_Mass [2/3]? Marker of uncertain stellar mass (4)
55- 58 I4 K Teff Effective temperature in K
60 I1 --- r_Teff [1]? 1: Teff from Zacs et al., 1998A&A...337..216Z 1998A&A...337..216Z
62- 66 F5.2 [Sun] [Fe/H] Iron abundance set equal to the overall model
metal abundance (5)
68- 71 F4.2 [cm/s2] logg Log of surface gravity
73 I1 --- r_logg [1]? 1: logg from Zacs et al., 1998A&A...337..216Z 1998A&A...337..216Z
75- 77 F3.1 km/s vt Microturbulence parameter
79 I1 --- r_vt [1]? 1: vt from Zacs et al., 1998A&A...337..216Z 1998A&A...337..216Z
81- 90 A10 --- Class MK spectral classification of the stars
according to the SIMBAD database
92-101 A10 --- Note Notes about the stars (6)
--------------------------------------------------------------------------------
Note (1): References for Stromgren photometry are numbered as follows:
1 = Olsen, 1983A&AS...54...55O 1983A&AS...54...55O
2 = Schuster & Nissen, 1988A&AS...73..225S 1988A&AS...73..225S
3 = Lindgren H., ESO (unpublished)
4 = Olsen, 1993, Cat. J/A+AS/102/89
5 = Hauck & Mermilliod, 1998, Cat. II/215
6 = Gronbech &.Olsen, 1976-77, Cat. II/33
7 = SIMBAD database
Note (2): The U velocity is positive in the direction of the galactic center
Note (3): Reference for Evolutionary tracks as follows:
1 = Adopted mass 0.80M☉
2 = VandenBerg et al., 2000ApJ...532..430V 2000ApJ...532..430V
Note (4): Marker of uncertain stellar mass as follows:
2 = The star is located on the lower side of the track
3 = The star is located where the tracks are very compact
Note (5): Abundances are expressed as the logarithm of the number abundance
of an element relative to hydrogen, and normalized to 0.0 for the
Solar ratio
Note (6): Notes about the stars have the following meaning:
Ba = barium star
b = binary
sp. b = spectroscopic binary
v = variable
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- Elem Element abbreviation
4- 5 I2 --- Z Atomic number
7 I1 --- Stage Ionization stage:
1: neutral, 2: singly ionized
9- 16 F8.3 0.1nm Lambda Air wavelength in Angstrom
19- 22 F4.2 --- logeps Solar photospheric abundance (1)
25- 29 F5.1 0.1pm EWSun Solar equivalent width in mA
32- 36 F5.2 --- loggf The oscillator strength multiplied with
the statistical weight, all in logarithm
39- 43 F5.3 eV Elow Lower transition level excitation energy
46 I1 --- Dflag [1/2] Pressure damping flag (2)
48- 51 F4.2 --- Dcorr Damping correction factor applied when
Dflag set to 0
54- 61 E8.2 s-1 Gamma Radiation damping constant
64- 65 A2 --- LevelL Lower level identification of the transition
67- 68 A2 --- LevelU Upper level identification of the transition
--------------------------------------------------------------------------------
Note (1): Abundances are expressed as the logarithm of the number abundance
of an element relative to hydrogen, plus 12.0
Note (2): Pressure damping flags defined as follows:
1 = The hydrogen collision broadening was adopted from Barklem et
al., 2000, Cat. J/A+AS/142/467, and references therein.
2 = Unsoeld (1955, Physik der Stematmospharen, 2nd ed., Berlin
Springer Verlag) approximation, i.e. the hydrogen collision
broadening was calculated following Mihalas D. 1978, "Stellar
Atmospheres", (W.H. Freeman & Co., San Francisco), with the
correction factor in column Dcorr multiplied to the resulting
broadening FWHM, Gamma
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- HD HD identification number
8- 12 F5.2 [Sun] [FeI/H] Iron abundance from Fe I (1)
14- 18 F5.2 [Sun] [OI/H] ? Oxygen abundance from O I (1),(2)
20- 24 F5.2 [Sun] [NaI/H] ? Sodium abundance from Na I (1)
26- 30 F5.2 [Sun] [MgI/H] ? Magnesium abundance from Mg I (1)
32- 36 F5.2 [Sun] [AlI/H] ? Aluminium abundance from Al I (1)
38- 42 F5.2 [Sun] [SiI/H] ? Silicon abundance from Si I (1)
44- 48 F5.2 [Sun] [CaI/H] ? Calcium abundance from Ca I (1)
50- 54 F5.2 [Sun] [ScII/H] ? Scandium abundance from Sc II (1)
56- 60 F5.2 [Sun] [TiI/H] ? Titanium abundance from Ti I (1)
62- 66 F5.2 [Sun] [VI/H] ? Vanadium abundance from V I (1)
68- 72 F5.2 [Sun] [CrI/H] ? Chromium abundance from Cr I (1)
74- 78 F5.2 [Sun] [FeII/H] ? Iron abundance from Fe II (1)
80- 84 F5.2 [Sun] [NiI/H] ? Nickel abundance from Ni I (1)
86- 90 F5.2 [Sun] [BaII/H] ? Barium abundance from Ba II (1)
92- 96 F5.2 [Sun] [alpha/H] ? α element abundance (1)(3)
98-102 F5.2 [Sun] [alpha'/H] ? α' element abundance (1)(4)
--------------------------------------------------------------------------------
Note (1): Abundances are expressed as the logarithm of the number abundance
of an element relative to hydrogen, and normalized to 0.0 for the
Solar ratio
Note (2): For oxygen, NLTE corrections have been applied
Note (3): The α element abundance is the straight mean value of the
abundances derived from Mg I, Si I, Ca I and Ti I
Note (4): The α' element abundance is the straight mean value of the
abundances derived from Mg I, Si I and Ca
--------------------------------------------------------------------------------
Acknowledgements: Karin Jonsell
(End) Karin Jonsell [Uppsala Astron. Obs.], Patricia Vannier [CDS] 02-May-2005