J/AJ/132/85 Equivalent width of 33 metal-poor RHB (Preston+, 2006)
Atmospheres, chemical compositions, and evolutionary histories of very
metal-poor red horizontal-branch stars in the galactic field and in
NGC 7078 (M15).
Preston G.W., Sneden C., Thompson I.B., Shectman S.A., Burley G.S.
<Astron. J., 132, 85-110 (2006)>
=2006AJ....132...85P 2006AJ....132...85P
ADC_Keywords: Stars, horizontal branch ; Stars, atmospheres ; Equivalent widths
Keywords: stars: abundances - stars: evolution - stars: horizontal-branch
Abstract:
We have conducted spectrum analyses of 24 field metal-poor ([Fe/H]←2)
red horizontal-branch (RHB) stars identified in the HK objective-prism
survey and 6 such stars in the globular cluster M15, based on
high-quality spectra (R∼40000, S/N∼100) obtained with the Magellan
Inamori Kyocera Echelle spectrograph at the Clay 6.5m telescope at
Las Campanas Observatory. The atmospheric parameters of the RHB stars
provide interesting bridges between turnoff stars of similar
temperature and red giant branch (RGB) stars of similar gravity, and
they permit investigations of abundance trends [X/Fe] versus [Fe/H] in
a relatively unexplored region of the temperature-gravity plane. We
find that the Teff, logg, vt, and [Fe/H] values determined from our
spectra are consistent with expectations from literature spectroscopic
studies of other evolved metal-poor stellar classes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 69 33 Star positions (from Simbad)
table5.dat 41 8382 Equivalent Widths
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See also:
J/A+A/380/578 : EW of 13 horizontal branch stars (Tautvaisiene+, 2001)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Star name
13- 14 I2 h RAh ? Simbad Hour of Right Ascension (J2000.0)
16- 17 I2 min RAm ? Simbad Minute of Right Ascension (J2000.0)
19- 22 F4.1 s RAs ? Simbad Second of Right Ascension (J2000.0)
24 A1 --- DE- Simbad Sign of the Declination (J2000.0)
25- 26 I2 deg DEd ? Simbad Degree of Declination (J2000.0)
28- 29 I2 arcmin DEm ? Simbad Arcminute of Declination (J2000.0)
31- 32 I2 arcsec DEs ? Simbad Arcsecond of Declination (J2000.0)
36- 40 F5.2 mag Bmag Simbad B band magnitude
42- 46 F5.2 mag Vmag Simbad V band magnitude
49- 69 A21 --- SName Simbad name
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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- 11 A11 --- Name Star name
14- 20 F7.2 0.1nm lambda Wavelength in Angstroms
22- 25 F4.1 --- Species Identification in atomic number and ion
27- 31 F5.2 eV chi Excitation potential
33- 37 F5.2 [---] log(gf) ? Log of the oscillator strength
39- 41 I3 10-13m EW ? Equivalent width (in mÅ)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 31-Aug-2007