J/A+A/439/129 HERES II. Spectroscopic analysis (Barklem+, 2005)
The Hamburg/ESO R-process enhanced star survey (HERES).
II. Spectroscopic analysis of the survey sample.
Barklem P.S., Christlieb N., Beers T.C., Hill V., Bessell M.S., Holmberg J.,
Marsteller B., Rossi S., Zickgraf F.-J., Reimers D.
<Astron. Astrophys., 439, 129-151 (2005)>
=2005A&A...439..129B 2005A&A...439..129B
ADC_Keywords: Stars, metal-deficient ; Abundances, peculiar ;
Spectra, ultraviolet
Keywords: stars: abundances - stars: population II - Galaxy: abundances -
Galaxy: evolution - Galaxy: halo
Abstract:
We present the results of analysis of "snapshot" spectra of 253
metal-poor halo stars -3.8≤[Fe/H]≤-1.5 obtained in the HERES survey.
The snapshot spectra have been obtained with VLT/UVES and have
typically S/N∼54 per pixel (ranging from 17 to 308), R∼20000,
lambda=3760-4980Å. This sample represents the major part of the
complete HERES sample of 373 stars; however, the CH strong content of
the sample is not dealt with here.
Description:
The spectra are analysed using an automated line profile analysis
method based on the Spectroscopy Made Easy (SME) codes of Valenti &
Piskunov (1996A&AS..118..595V 1996A&AS..118..595V). Elemental abundances of moderate
precision (absolute rms errors of order 0.25dex, relative rms errors
of order 0.15dex) have been obtained for 22 elements, C, Mg, Al, Ca,
Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, and
Eu, where detectable. Of these elements, 14 are usually detectable at
the 3sigma confidence level for our typical spectra. The remainder can
be detected in the least metal-poor stars of the sample, spectra with
higher than average S/N, or when the abundance is enhanced.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 41 253 The sample
table2a.dat 72 253 Derived stellar atmosphere parameters for
the sample
table2b.dat 54 5566 Elemental abundances for the sample
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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- 13 A13 --- Name Star name (1)
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 24 F4.1 s RAs Right ascension (J2000)
26 A1 --- DE- Declination sign (J2000)
27- 28 I2 deg DEd Declination (J2000)
30- 31 I2 arcmin DEm Declination (J2000)
33- 34 I2 arcsec DEs Declination (J2000)
36- 41 F6.1 km/s RV Barycentric radial velocity (2)
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Note (1): Coordinates of the HES stars (prefix HE) have been derived
from the Digitized Sky Survey I and are accurate to 1".
Coordinates of the HK survey stars (prefix CS, BPS CS NNNN in Simbad)
are from identifications of the sources in the 2MASS All Sky Release,
Cat. II/246.
Note (2): Barycentric radial velocities were measured from the snapshot
spectra and are accurate to a few km/s.
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Byte-by-byte Description of file: table2a.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Star name
15- 17 I3 --- S/N Average signal-to-noise ratio per pixel for
the whole observed spectrum
19- 22 I4 K Teff Effective temperature
24- 26 I3 K e_Teff rms uncertainty on Teff
28- 31 F4.2 [cm/s+2] logg Surfave gravity
33- 36 F4.2 [cm/s+2] e_logg Relative rms error estimate on logg
38- 41 F4.2 [cm/s+2] E_logg Absolute rms error estimate on logg
43- 47 F5.2 [Sun] [Fe/H] Abundance [Fe/H]
49- 52 F4.2 [Sun] e_[Fe/H] Relative rms error estimate on [Fe/H]
54- 57 F4.2 [Sun] E_[Fe/H] Absolute rms error estimate on [Fe/H]
59- 62 F4.2 km/s Vt Microturbulence velocity
64- 67 F4.2 km/s e_Vt Relative rms error estimate on Vt
69- 72 F4.2 km/s E_Vt Absolute rms error estimate on Vt
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Byte-by-byte Description of file: table2b.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Name Star name
15- 16 A2 --- El Element
18- 22 F5.2 [---] logEpsX ?=-9.99 log of abundance for the element
24- 27 F4.2 [---] e_logEpsX ?=0.00 Relative rms error estimate on logEpsX
29- 32 F4.2 [---] E_logEpsX ?=0.00 Absolute rms error estimate on logEpsX
34- 38 F5.2 [---] [X/Fe] ?=-9.99 Abundance [X/Fe]
40- 43 F4.2 [---] e_[X/Fe] ?=0.00 Relative rms error estimate on [X/Fe]
45- 48 F4.2 [---] E_[X/Fe] ?=0.00 Absolute rms error estimate on [X/Fe]
50- 51 I2 --- N Number of features of the element used (1)
53- 54 I2 --- N3 Number of features of the element used
classified as 3sigma detections (2)
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Note (1): Number of features of the element used in each star, noting that
this varies from star to star as certain features may be automatically
rejected if the star has a strong G band, if the feature is near a
Balmer line in warmer stars (see Sect. 3.2), or if they are determined
to be affected by a cosmic ray hit or bad pixel.
Note (2): Number of the features used, classified as 3sigma detections.
In the case of CH bands we simply classify detections and
non-detections with 1 and 0 respectively.
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History:
* 27-Jul-2006: From electronic version of the journal
In table1, HE 0249-0126, that was in the original version of the table,
was suppressed, and HE 1237-3103 was added (From author).
References:
Christlieb et al., Paper I 2004A&A...428.1027C 2004A&A...428.1027C
(End) Patricia Vannier [CDS] 27-Jul-2006