J/A+A/666/A125 Abundances of disk and bulge giants (Forsberg+, 2022)
Abundances of disk and bulge giants from high-resolution optical spectra.
V. Molybdenum: The p-process element.
Forsberg R., Ryde N., Jonsson H., Rich R.M., Johansen A.
<Astron. Astrophys. 666, A125 (2022)>
=2022A&A...666A.125F 2022A&A...666A.125F (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Abundances ; Spectroscopy ; Optical
Keywords: stars: abundances - Galaxy: abundances - Galaxy: bulge -
Galaxy: disk - Galaxy: evolution - solar neighborhood
Abstract:
In this work, we aim to make a differential comparison of the
neutron-capture and p-process element molybdenum (Mo) in the stellar
populations in the local disk(s) and the bulge, focusing on minimising
possible systematic effects in the analysis.
The stellar sample consists of 45 bulge and 291 local disk K-giants
observed with high-resolution optical spectra. The abundances are
determined by fitting synthetic spectra using the Spectroscopy Made
Easy (SME) code. The disk sample is separated into thin- and
thick-disk components using a combination of abundances and
kinematics. The cosmic origin of Mo is investigated and discussed by
comparing with published abundances of Mo and the neutron-capture
elements cerium (Ce) and europium (Eu).
We determine reliable Mo abundances for 35 bulge and 282 disk giants
with a typical uncertainty of [Mo/Fe] ∼0.2 and ∼0.1dex for the
bulge and disk, respectively.
We find that the bulge is possibly enhanced in [Mo/Fe] compared to the
thick disk, which we do not observe in either [Ce/Fe] or [Eu/Fe]. This
might suggest a higher past star-formation rate in the bulge; however,
as we do not observe the bulge to be enhanced in [Eu/Fe], the origin
of the molybdenum enhancement is yet to be constrained. Although the
scatter is large, we may be observing evidence of the p-process
contributing to the heavy element production in the chemical evolution
of the bulge.
Description:
We present abundances of the element molybdenum (Mo, Z=42) for a
sample of 291 K giants in the solar neighborhood and 45 K giants in
the bulge. For the local disk stars, we used observations obtained
with the spectrograph FIES at NOT, and from archives (FIES and
PolarBase), while for the bulge stars, the observations were taken
with the UVES/FLAMES spectrograph at VLT. The FIES spectra have
R=67000, the PolarBase spectra have R=67000, and the UVES/FLAMES
spectra have R=47000. In general, most disk stars are very bright and
have S/N around 100, the bulge stars are fainter with S/R of 10-80.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 95 291 Basic data for the observed bulge giants
tablea2.dat 42 291 Stellar parameters and abundances for observed
bulge giants
tablea3.dat 41 45 Basic data for the observed disk giants
tablea4.dat 31 45 Stellar parameters and abundances for observed
disk giants
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See also:
J/A+A/598/A100 : Abundances of disk giants: O, Mg, Ca and Ti (Jonsson+, 2017)
J/A+A/625/A141 : Abundances of disk and bulge giants (Lomaeva+, 2019)
J/A+A/631/A113 : Abund. of disk + bulge giants: Zr, La, Ce, Eu (Forsberg, 2019)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Name (HIP, KIC or TYC)
16- 31 A16 --- AName Alternative name
33- 34 I2 h RAh Right ascension (J2000)
36- 37 I2 min RAm Right ascension (J2000)
39- 46 F8.5 s RAs Right ascension (J2000)
48 A1 --- DE- Declination sign (J2000)
49- 50 I2 deg DEd Declination (J2000)
52- 53 I2 arcmin DEm Declination (J2000)
55- 61 F7.4 arcsec DEs Declination (J2000)
63- 67 F5.2 mag Vmag V magnitude
69- 75 F7.2 km/s RV Radial velocity
77- 79 I3 --- S/N Signal-to-noise ratio (1)
81- 95 A15 --- Ref Source of spectrum (2)
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Note (1): As measured by http://www.stecf.org/software/ASTROsoft/DER_SNR
Note (2): Thygesen+2012 for Thygesen et al., 2012, Cat. J/A+A/543/160.
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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- 14 A14 --- Name Name (HIP, KIC or TYC)
18- 21 I4 K Teff Effective temperature
23- 26 F4.2 [cm/s2] logg Surface gravity
28- 32 F5.2 [-] [Fe/H] Relative iron abundance
34- 37 F4.2 km/s vmic Mictoturbulence velocity
39- 42 F4.2 --- A(Mo) ? Molybdenum abundance
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Name
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 18 F6.3 s RAs Right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 31 F5.2 arcsec DEs Declination (J2000)
33- 38 F6.3 mag Vmag V magnitude
40- 41 I2 --- S/N Signal-to-noise ratio (1)
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Note (1): As measured by http://www.stecf.org/software/ASTROsoft/DER_SNR
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Byte-by-byte Description of file: tablea4.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Name
7- 10 I4 K Teff Effective temperature
12- 15 F4.2 [cm/s2] logg Surface gravity
17- 21 F5.2 [-] [Fe/H] Relative iron abundance
23- 26 F4.2 km/s vmic Mictoturbulence velocity
28- 31 F4.2 --- A(Mo) ? Molybdenum abundance
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Acknowledgements:
Rebecca Forsberg, rebecca(at)astro.lu.se
References:
Jonsson et al., Paper I 2017A&A...598A.100J 2017A&A...598A.100J, Cat. J/A+A/598/A100
Jonsson et al., Paper II 2017A&A...598A.101J 2017A&A...598A.101J
Lomaeva et al., Paper III 2019A&A...625A.141L 2019A&A...625A.141L, Cat. J/A+A/625/A141
Forsberg et al. Paper IV 2019A&A...631A.113F 2019A&A...631A.113F, Cat. J/A+A/631/A113
(End) Patricia Vannier [CDS] 29-Jul-2022