J/MNRAS/446/2348 Chemical analysis of CH stars. II. (Karinkuzhi+, 2015)
Chemical analysis of CH stars -
II. Atmospheric parameters and elemental abundances.
Karinkuzhi D., Goswami A.
<Mon. Not. R. Astron. Soc., 446, 2348-2362 (2015)>
=2015MNRAS.446.2348K 2015MNRAS.446.2348K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, carbon ; Stars, late-type ; Abundances ; Equivalent widths
Keywords: stars: abundances - stars: carbon - stars: late-type -
stars: Population II
Abstract:
We present detailed chemical analyses for a sample of 12 stars
selected from the CH star catalogue of Bartkevicius (1996BaltA...5..217B 1996BaltA...5..217B).
The sample includes two confirmed binaries, four objects that are
known to show radial velocity variations and the rest with no
information on the binary status. A primary objective is to examine if
all these objects exhibit chemical abundances characteristics of CH stars,
based on detailed chemical composition study using high-resolution
spectra. We have used high-resolution (R∼42000) spectra from the
ELODIE archive (Moultaka et al. 2004PASP..116..693M 2004PASP..116..693M). These spectra
cover 3900 to 6800 Å in the wavelength range. We have estimated the
stellar atmospheric parameters, the effective temperature Teff, the
surface gravity log g, and metallicity [Fe/H] from local thermodynamic
equilibrium analysis using model atmospheres. Estimated temperatures
of these objects cover a wide range from 4200 to 6640 K, the surface
gravity from 0.6 to 4.3 and metallicity from -0.13 to -1.5. We report
updates on elemental abundances for several heavy elements, Sr, Y, Zr,
Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. For the object HD 89668, we present
the first abundance analyses results. Enhancement of heavy elements
relative to Fe, a characteristic property of CH stars is evident from
our analyses in the case of four objects, HD 92545, HD 104979, HD 107574
and HD 204613. A parametric-model-based study is performed to
understand the relative contributions from the s- and r-process to the
abundances of the heavy elements.
Description:
Low-resolution spectra of these objects obtained from 2m Himalayan
Chandra Telescope at the Indian Astronomical Observatory, Hanle using
HFOSC clearly show strong features due to carbon. HFOSC is an optical
imager cum spectrograph for conducting low- and medium-resolution
grism spectroscopy (http://www.iiap.res.in/iao/hfosc.html).
High-resolution spectra necessary for abundance analyses of the
programme stars are taken from the ELODIE archive (Moultaka et al.
2004PASP..116..693M 2004PASP..116..693M).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 66 12 Basic data for the programme stars
table4a.dat 71 197 Fe lines used for deriving atmospheric
parameters for the first 6 objects
table4b.dat 70 197 Fe lines used for deriving atmospheric
parameters for the next 6 objects
table8a.dat 71 140 Equivalent widths in mÅ of lines used for
the calculation of light element abundances for
first 6 objects
table8b.dat 70 140 Equivalent widths in mÅ of lines used for
the calculation of light element abundances for
next 6 objects
table9a.dat 71 100 Equivalent widths in mÅ of lines used for
abundance determination of heavy elements for
the first 6 objects
table9b.dat 70 100 Equivalent widths in mÅ of lines used for
abundance determination of heavy elements for
the next 6 objects
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See also:
J/ApJS/105/419 : Spectral Atlas of Carbon Stars (Barnbaum+ 1996)
J/MNRAS/440/1095 : Chemical analysis of CH stars (Karinkuzhi+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Star name (HD NNNNNN)
11- 12 I2 --- Num [1/12] Star number, as in other tables
14- 15 I2 h RAh Simbad Hour of Right Ascension (J2000)
17- 18 I2 min RAm Simbad Minute of Right Ascension (J2000)
20- 24 F5.2 s RAs Simbad Second of Right Ascension (J2000)
26 A1 --- DE- Simbad Sign of the Declination (J2000)
27- 28 I2 deg DEd Simbad Degree of Declination (J2000)
30- 31 I2 arcmin DEm Simbad Arcminute of Declination (J2000)
33- 37 F5.2 arcsec DEs Simbad Arcsecond of Declination (J2000)
39- 43 F5.2 mag Bmag Simbad B-band magnitude
45- 48 F4.2 mag Vmag Simbad V-band magnitude
50- 54 F5.3 mag Jmag Simbad J-band magnitude
56- 60 F5.3 mag Hmag Simbad H-band magnitude
62- 66 F5.3 mag Kmag Simbad K-band magnitude
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Byte-by-byte Description of file: table4a.dat
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Bytes Format Units Label Explanations
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1- 8 F8.3 0.1nm Wave Wavelength (Å)
10- 14 A5 --- El Element
16- 20 F5.3 eV Elow Lower energy level
22- 27 F6.3 [-] loggf Oscillator strength
29- 35 F7.3 0.1pm Abund1 ? HD 55496 abundance
37- 43 F7.3 0.1pm Abund2 ? HD 89668 abundance
45- 50 F6.2 0.1pm Abund3 ? HD 92545 abundance
52- 57 F6.2 0.1pm Abund4 ? HD 104979 abundance
59- 64 F6.2 0.1pm Abund5 ? HD 107574 abundance
66- 71 F6.2 0.1pm Abund6 ? HD 111721 abundance
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Byte-by-byte Description of file: table4b.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.3 0.1nm Wave Wavelength (Å)
10- 14 A5 --- El Element
16- 20 F5.3 eV Elow Lower energy level
22- 27 F6.3 [-] loggf Oscillator strength
29- 34 F6.2 0.1pm Abund7 ? HD 122202 abundance
36- 41 F6.2 0.1pm Abund8 ? HD 126681 abundance
43- 48 F6.2 0.1pm Abund9 ? HD 148897 abundance
50- 55 F6.2 0.1pm Abund10 ? HD 164922 abundance
57- 62 F6.2 0.1pm Abund11 ? HD 167768 abundance
64- 70 F7.3 0.1pm Abund12 ? HD 204613 abundance
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Byte-by-byte Description of file: table8a.dat table9a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.3 0.1nm Wave Wavelength (Å)
10- 14 A5 --- El Element
16- 20 F5.3 eV Elow Lower energy level
22- 27 F6.3 [-] loggf Oscillator strength
29- 35 F7.3 0.1pm EW1 ? HD 55496 equivalent width of line (mÅ)
37- 43 F7.3 0.1pm EW2 ? HD 89668 equivalent width of line (mÅ)
45- 50 F6.2 0.1pm EW3 ? HD 92545 equivalent width of line (mÅ)
52- 57 F6.2 0.1pm EW4 ? HD 104979 equivalent width of line (mÅ)
59- 64 F6.2 0.1pm EW5 ? HD 107574 equivalent width of line (mÅ)
66- 71 F6.2 0.1pm EW6 ? HD 111721 equivalent width of line (mÅ)
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Byte-by-byte Description of file: table8b.dat table9b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.3 0.1nm Wave Wavelength (Å)
10- 14 A5 --- El Element
16- 20 F5.3 eV Elow Lower energy level
22- 27 F6.3 [-] loggf Oscillator strength
29- 34 F6.2 0.1pm EW7 ? HD 122202 equivalent width of line (mÅ)
36- 41 F6.2 0.1pm EW8 ? HD 126681 Equivalent width of line (mÅ)
43- 48 F6.2 0.1pm EW9 ? HD 148897 equivalent width of line (mÅ)
50- 55 F6.2 0.1pm EW10 ? HD 164922 equivalent width of line (mÅ)
57- 62 F6.2 0.1pm EW11 ? HD 167768 equivalent width of line (mÅ)
64- 70 F7.3 0.1pm EW12 ? HD 204613 equivalent width of line (mÅ)
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History:
From electronic version of the journal
References:
Karinkuzhi et al., Paper I., 2014MNRAS.440.1095K 2014MNRAS.440.1095K, Cat. J/MNRAS/440/1095
(End) Tiphaine Pouvreau [CDS] 31-Oct-2017