J/MNRAS/487/3797 A bright star sample observed with SOPHIE (Bonifacio+, 2019)
The Pristine survey - V. A bright star sample observed with SOPHIE.
Bonifacio P., Caffau E., Sestito F., Lardo C., Martin N.F., Starkenburg E.,
Sbordone L., Francois P., Jablonka P., Henden A.A., Salvadori S.,
Gonzalez Hernandez J.I., Aguado D.S., Hill V., Venn K., Navarro J.F.,
Arentsen A., Sanchez-Janssen R., Carlberg R.
<Mon. Not. R. Astron. Soc., 487, 3797-3814 (2019)>
=2019MNRAS.487.3797B 2019MNRAS.487.3797B (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Stars, atmospheres ; Stars, population II ;
Radial velocities ; Space velocities ; Optical
Keywords: stars: abundances - stars: atmospheres - stars: Population II
stars: kinematics and dynamics - Galaxy: abundances -
Galaxy: evolution
Abstract:
With the aim of probing the properties of the bright end of the
Pristine survey and its effectiveness in selecting metal-poor stars,
we selected a sample of bright candidate metal-poor stars combining
Pristine CaHK photometry with APASS gi photometry, before the Gaia
second data release became available. These stars were observed with
the SOPHIE spectrograph at the 1.93m telescope of Observatoire de
Haute Provence and we used photometry and parallaxes from Gaia DR2 to
derive their atmospheric parameters. Chemical abundances were
determined from the spectra for 40 stars of the sample. Eight stars
were confirmed to be very metal-poor ([Fe/H]←2.0), as expected from
the photometric estimate. No star was found with [Fe/H]←3.0, although
for nine stars the photometric estimate was below this value. Three
multiple systems are identified from their multipeaked
cross-correlation functions. Two metal-poor stars with [Fe/H]~-1.0
have an age estimate of about 4Gyr. Accretion from a satellite galaxy
is a possible explanation for these 'young metal-poor stars', but they
could also be field blue stragglers. Galactic orbits for our sample of
stars allowed us to divide them into three classes that we label
'Halo', 'Thick', and 'Thin' and tentatively identify as halo, thick
disc, and thin disc. We present a new method for deriving photometric
metallicities, effective temperatures, and surface gravities by
combining Gaia parallaxes, photometry, and Pristine CaHK photometry.
Comparison with spectroscopic metallicities shows a very good
agreement and suggests that we can further improve the efficiency of
Pristine CaHK in selecting metal-poor stars.
Description:
The SOPHIE spectra were acquired during two runs, the first between
2018 February 16 and February 20 (observer P. Bonifacio) and the
second between 2018 April 13 and April 17 (observer F. Sestito). We
always used the High Efficiency mode, which provides a resolving power
R=39000, with one fibre on the object (fibre A) and one on the sky
(fibre B). The spectra cover the wavelength range 387.2-694.3nm. The
typical integration time was 1h for each star. During the observations
we aimed at a signal-to-noise ratio, as estimated from the
exposure-meter, in the range 15-20. For some stars we took several
exposures or lengthened the exposure time in order to reach this.
To derive the stellar parameters, we used Gaia DR2 (Gaia Collaboration
2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345). Reddennings were derived from the
maps of Green et al. (2018MNRAS.478..651G 2018MNRAS.478..651G). By using the parallax, we
derived the absolute G magnitude (Gabs=G+5+5log(plx)). This latter
value combined with the Gaia (GBP-GRP) colour was compared to
PARSEC (Bressan et al. 2012MNRAS.427..127B 2012MNRAS.427..127B; Marigo et al.
2017ApJ...835...77M 2017ApJ...835...77M) isochrones of metallicity close to the
metallicity estimate, in order to derive the effective temperature
(Teff) and the surface gravity (logg) of each star.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 41 5 Measured radial velocities of
Pristine_113.6058+45.8841
table2.dat 87 45 Stellar parameters
table3.dat 95 40 Chemical abundances of iron, sodium, magnesium,
aluminium, silicon, and sulphur
table4.dat 105 40 Chemical abundances of calcium to manganese
table5.dat 96 40 Chemical abundances of cobalt to barium
table7.dat 30 13 Carbon abundances for the cool stars
tablea1.dat 104 44 Inferred orbital parameters of the stars in the
sample (space velocities, apocentre and
pericentre distances)
tablea2.dat 151 44 Inferred orbital parameters of the stars in the
sample (eccentricities, energies, actions and
maximum heights)
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 F15.7 d BJD Barycentric Julian date
17- 19 F3.1 km/s RV1 ? Radial velocity of the first peak
21- 24 F4.1 km/s RV2 ? Radial velocity of the second peak
26- 29 F4.1 km/s RV Mean radial velocity estimated by fitting a
single gaussian
31- 41 A11 --- Comment Shape of the cross correlation function
(Single peak or Double peak)
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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- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27 A1 --- f_Name Flag on Name (1)
29- 30 I2 h RAh Right ascension (J2000)
32- 33 I2 min RAm Right ascension (J2000)
35- 39 F5.2 s RAs Right ascension (J2000)
41 A1 --- DE- Declination sign (J2000)
42- 43 I2 deg DEd Declination (J2000)
45- 46 I2 arcmin DEm Declination (J2000)
48- 49 I2 arcsec DEs Declination (J2000)
51- 55 F5.2 mag Vmag V-band magnitude
57- 62 F6.1 km/s RV ? Radial velocity
64- 67 I4 K Teff ? Effective temperature
69- 72 F4.2 [cm/s2] logg ? Surface gravity
74- 76 F3.1 km/s vt ? Microturbulence velocity
78- 82 F5.2 [-] [Fe/H] ? Fe to hydrogen abundance ratio
84- 87 F4.2 [-] e_[Fe/H] ? Error on [Fe/H] (G1)
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Note (1): Flag as follows:
M = Multiple system
F = F star or star with low S/N spectra
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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- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27- 30 F4.2 [-] A(FeI) FeI to hydrogen abundance ratio
32- 35 F4.2 [-] e_A(FeI) Error on A(FeI) (G1)
37- 40 F4.2 [-] A(FeII) FeII to hydrogen abundance ratio
42- 45 F4.2 [-] e_A(FeII) ? Error on A(FeII) (G1)
47- 50 F4.2 [-] A(Na) ? Sodium abundance
52- 55 F4.2 [-] e_A(Na) ? Error on A(Na) (G1)
57- 60 F4.2 [-] A(Mg) ? Magnesium abundance
62- 65 F4.2 [-] e_A(Mg) ? Error on A(Mg) (G1)
67- 70 F4.2 [-] A(Al) ? Aluminium abundance
72- 75 F4.2 [-] A(SiI) ? Silicon Si I abundance
77- 80 F4.2 [-] e_A(SiI) ? Error on A(SiI) (G1)
82- 85 F4.2 [-] A(SiII) ? Silicon Si II abundance
87- 90 F4.2 [-] e_A(SiII) ? Error on A(SiII) (G1)
92- 95 F4.2 [-] A(S) ? Sulphur abundance
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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- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27- 30 F4.2 [-] A(Ca) Calcium abundance
32- 35 F4.2 [-] e_A(Ca) ? Error on A(Ca) (G1)
37- 40 F4.2 [-] A(Sc) ? Scandium abundance
42- 45 F4.2 [-] e_A(Sc) ? Error on A(Sc) (G1)
47- 50 F4.2 [-] A(TiI) ? Titanium Ti I abundance
52- 55 F4.2 [-] e_A(TiI) ? Error on A(TiI) (G1)
57- 60 F4.2 [-] A(TiII) ? Titanium Ti II abundance
62- 65 F4.2 [-] e_A(TiII) ? Error on A(TiII) (G1)
67- 70 F4.2 [-] A(V) ? Vanadium abundance
72- 75 F4.2 [-] e_A(V) ? Error on A(V) (G1)
77- 80 F4.2 [-] A(CrI) ? Chromium Cr I abundance
82- 85 F4.2 [-] e_A(CrI) ? Error on A(CrI) (G1)
87- 90 F4.2 [-] A(CrII) ? Chromium Cr II abundance
92- 95 F4.2 [-] e_A(CrII) ? Error on A(CrII) (G1)
97-100 F4.2 [-] A(Mn) ? Manganese abundance
102-105 F4.2 [-] e_A(Mn) ? Error on (Mn) (G1)
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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- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27- 30 F4.2 [-] A(Co) ? Cobalt abundance
32- 35 F4.2 [-] A(Ni) ? Nickel abundance
37- 40 F4.2 [-] e_A(Ni) ? Error on A(Ni) (G1)
42- 45 F4.2 [-] A(Cu) ? Copper abundance
47- 50 F4.2 [-] e_A(Cu) ? Error on A(Cu) (G1)
52- 55 F4.2 [-] A(Zn) ? Zinc abundance
57- 60 F4.2 [-] e_A(Zn) ? Error on A(Zn) (G1)
62- 65 F4.2 [-] A(Sr) ? Strontium abundance
67- 70 F4.2 [-] e_A(Sr) ? Error on A(Sr) (G1)
72- 75 F4.2 [-] A(Y) ? Yttrium abundance
77- 80 F4.2 [-] e_A(Y) ? Error on A(Y) (G1)
82- 85 F4.2 [-] A(Zr) ? Zirconium abundance
87- 91 F5.2 [-] A(Ba) ? Barium abundance
93- 96 F4.2 [-] e_A(Ba) ? Error on A(Ba) (G1)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27- 30 F4.2 [-] A(C) Carbon abundance
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27- 32 F6.1 km/s ULSR Space velocity U with respect to the Local
Standard of Rest
34- 37 F4.1 km/s E_ULSR Upper error on U
39- 42 F4.1 km/s e_ULSR Lower error on U
44- 49 F6.1 km/s VLSR Space velocity V with respect to the Local
Standard of Rest
51- 54 F4.1 km/s E_VLSR Upper error on V
56- 59 F4.1 km/s e_VLSR Lower error on V
61- 66 F6.1 km/s WLSR Space velocity W with respect to the Local
Standard of Rest
68- 71 F4.1 km/s E_WLSR Upper error on W
73- 76 F4.1 km/s e_WLSR Lower error on W
78- 81 F4.1 kpc Apo Apocentre distance in the galactocentric frame
83- 87 F5.1 kpc E_Apo Upper error on Apo
89- 92 F4.1 kpc e_Apo Lower error on Apo
94- 96 F3.1 kpc Peri Pericentre distance in the galactocentric
frame
98-100 F3.1 kpc E_Peri Upper error on Peri
102-104 F3.1 kpc e_Peri Lower error on Peri
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- Name Star name (Pristine_DDD.dddd+DD.dddd)
27- 31 F5.3 --- ecc Eccentricity of the orbit (1)
33- 37 F5.3 --- E_ecc Upper error on ecc
39- 43 F5.3 --- e_ecc Lower error on ecc
45- 52 F8.1 km2/s2 E Energy of the orbit
54- 60 F7.1 km2/s2 E_E Upper error on E
62- 68 F7.1 km2/s2 e_E Lower error on E
70- 75 F6.1 kpc.km/s Jphi Rotational component of the action
77- 81 F5.1 kpc.km/s E_Jphi Upper error on Jphi
83- 87 F5.1 kpc.km/s e_Jphi Lower error on Jphi
89- 94 F6.1 kpc.km/s Jr Radial component of the action
96-100 F5.1 kpc.km/s E_Jr Upper error on Jr
102-106 F5.1 kpc.km/s e_Jr Lower error on Jr
108-113 F6.1 kpc.km/s Jz Vertical component of the action
115-120 F6.1 kpc.km/s E_Jz Upper error on Jz
122-126 F5.1 kpc.km/s e_Jz Lower error on Jz
128-132 F5.2 kpc zmax Maximum height of the orbit above the
galactic plane
134-139 F6.2 kpc E_zmax Upper error on zmax
141-145 F5.2 kpc e_zmax Lower error on zmax
147-151 A5 --- Orbit Type of the orbit (Thin, Thick, Halo)
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Note (1): The eccentricity is defined as ecc=(rapo-rperi)/(rapo+rperi)
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Global Notes:
Note (G1): Line-to-line scatter, if there is none, the abundance has been
derived from a single line
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History:
From electronic version of the journal
References:
Starkenburg et al. Paper I 2017MNRAS.471.2587S 2017MNRAS.471.2587S
Caffau et al. Paper II 2017AN....338..686C 2017AN....338..686C, Cat. J/AN/338/686
Youakim et al. Paper III 2017MNRAS.472.2963Y 2017MNRAS.472.2963Y, Cat. J/MNRAS/472/2963
Starkenburg et al. Paper IV 2018MNRAS.481.3838S 2018MNRAS.481.3838S
(End) Ana Fiallos [CDS] 17-Nov-2022