J/A+A/625/A141 Abundances of disk and bulge giants (Lomaeva+, 2019)
Abundances of disk and bulge giants from high-resolution optical spectra.
III. Sc, V, Cr, Mn, Co, Ni.
Lomaeva M., Joensson H., Ryde N., Schultheis M., Thorsbro B.
<Astron. Astrophys. 625, A141 (2019)>
=2019A&A...625A.141L 2019A&A...625A.141L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, giant ; Abundances ; Spectroscopy
Keywords: Galaxy: evolution - solar neighborhood - stars: abundances
Abstract:
The formation and evolution of the Galactic bulge and the Milky Way is
still a debated subject. Observations of the X-shaped bulge,
cylindrical stellar motions, and the presumed existence of a fraction
of young stars in the bulge have suggested that it formed through
secular evolution of the disk and not through gas dissipation and/or
mergers, as thought previously.
Our goal was to measure the abundances of six iron-peak elements (Sc,
V, Cr, Mn, Co, and Ni) in the local thin and thick disks and in the
bulge. These abundances can provide additional observational
constraints for Galaxy formation and chemical evolution models, and
help us to understand whether the bulge has emerged from the thick
disk or not.
We use high-resolution optical spectra of 291 K giants in the local
disk mostly obtained by the FIES at NOT (signal-to-noise ratio (S/N)
of 80-100) and 45K giants in the bulge obtained by the UVES/FLAMES at
VLT (S/N of 10-80). The abundances are measured using Spectroscopy
Made Easy (SME). Additionally, we apply non-local thermodynamic
equilibrium (NLTE) corrections to the ratios [Mn/Fe] and [Co/Fe]. The
thin and thick disks were separated according to their metallicity,
[Ti/Fe], as well as proper motions and the radial velocities from Gaia
DR2.
The trend of [V/Fe] vs. [Fe/H] shows a separation between the disk
components, being more enhanced in the thick disk. Similarly, the
[Co/Fe] vs. [Fe/H] trend shows a hint of an enhancement in the local
thick disk. The trends of V and Co in the bulge appear to be even more
enhanced, although within the uncertainties. The decreasing value of
[Sc/Fe] with increasing metallicity is observed in all the components,
while our [Mn/Fe] value steadily increases with increasing metallicity
in the local disk and the bulge instead. For Cr and Ni we find a flat
trend following iron for the whole metallicity range in the disk and
the bulge. The ratio of [Ni/Fe] appears slightly overabundant in the
thick disk and the bulge compared to the thin disk, although the
difference is minor.
The somewhat enhanced ratios of [V/Fe] and [Co/Fe] observed in the
bulge suggest that the local thick disk and the bulge might have
experienced different chemical enrichment and evolutionary paths.
However, we are unable to predict the exact evolutionary path of the
bulge solely based on these observations. Galactic chemical evolution
models could, on the other hand, allow us to predict them using these
results.
Description:
We present abundances of six iron-peak elements: Sc, V, Cr, Mn, Co,
and Ni for 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:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 95 291 Basic data for the observed disk giants
tablea2.dat 41 45 Basic data for the observed bulge giants
tablea3.dat 30 98 Atomic line data for lines analyzed
tablea4.dat 75 291 Stellar parameters and abundances for
observed disk giants
tablea5.dat 64 45 Stellar parameters and abundances for
observed bulge giants
--------------------------------------------------------------------------------
See also:
J/A+A/543/A160 : Normalized spectra of 82 Kepler red giants (Thygesen+, 2012)
J/A+A/598/A100 : Abundances of disk giants: O, Mg, Ca and Ti (Jonsson+, 2017)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
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 --- Source Source of spectrum (2)
--------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
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)
--------------------------------------------------------------------------------
Note (1): As measured by http://www.stecf.org/software/ASTROsoft/DER_SNR
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Name Element
6- 14 F9.4 0.1nm lambda Wavelength
16- 21 F6.3 --- loggf log(gf) value
23- 28 F6.4 eV Eexc Excitation energy
30 I1 --- r_loggf Reference for loggf (1)
--------------------------------------------------------------------------------
Note (1): References for loggf as follows:
1 = Kurucz, R.L. 2009, Robert L. Kurucz on-line database of observed and
predicted atomic transitions
2 = Lawler, J.E. & Dakin, J.T., 1989JOSAB...6...11B 1989JOSAB...6...11B
3 = Whaling et al., 1985A&A...153..109W 1985A&A...153..109W
4 = Sobeck et al., 2007ApJ...667.1267S 2007ApJ...667.1267S
5 = Kurucz, R.L. 2010, Robert L. Kurucz on-line database of observed and
predicted atomic transitions
6 = Blackwell-Whitehead, R. & Bergemann, M, 2007A&A...472L..43B 2007A&A...472L..43B
7 = Cardon et al., 1982ApJ...260..395C 1982ApJ...260..395C
8 = Wood et al., 2014ApJS..211...20W 2014ApJS..211...20W
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Name Name (HIP, KIC or TYC)
16- 19 I4 K Teff Effective temperature
21- 24 F4.2 [cm/s2] logg Surface gravity
26- 30 F5.2 [-] [Fe/H] Relative iron abundance
32- 35 F4.2 km/s Vmic Microturbulence velocity
37- 40 F4.2 --- A(Sc) Scandium abundance
42- 47 F6.2 --- A(V) ?=-99.99 Vanadium abundance
49- 54 F6.2 --- A(Cr) ?=-99.99 Chromium abundance
56- 61 F6.2 --- A(Mn) ?=-99.99 Manganese abundance
63- 68 F6.2 --- A(Co) ?=-99.99 Cobalt abundance
70- 75 F6.2 --- A(Ni) ?=-99.99 Nickel abundance
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
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 Microturbulence velocity
28- 31 F4.2 --- A(Sc) Scandium abundance
33- 38 F6.2 --- A(V) ?=-99.99 Vanadium abundance
40- 45 F6.2 --- A(Cr) ?=-99.99 Chromium abundance
47- 52 F6.2 --- A(Mn) ?=-99.99 Manganese abundance
54- 59 F6.2 --- A(Co) ?=-99.99 Cobalt abundance
61- 64 F4.2 --- A(Ni) Nickel abundance
--------------------------------------------------------------------------------
Acknowledgements:
Maria Lomaeva, nat13mlo(at)student.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
(End) Patricia Vannier [CDS] 07-May-2019