J/MNRAS/486/5349 Chemical compositions of Galactic bulge stars (Duong+, 2019)
HERBS II: Detailed chemical compositions of Galactic bulge stars.
Duong L., Asplund M., Nataf D.M., Freeman K.C., Ness M.
<Mon. Not. R. Astron. Soc., 486, 5349-5361 (2019)>
=2019MNRAS.486.5349D 2019MNRAS.486.5349D (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Milky Way ; Spectroscopy ; Optical ; Infrared
Keywords: stars: abundances - Galaxy: bulge - Galaxy: evolution -
Galaxy: formation
Abstract:
This work explores the detailed chemistry of the Milky Way bulge using
the HERMES spectrograph on the Anglo-Australian Telescope. Here, we
present the abundance ratios of 13 elements for 832 red giant branch
and clump stars along the minor bulge axis at latitudes
b=-10°,-7.5°, and -5°. Our results show that none of the
abundance ratios vary significantly with latitude. We also observe
disc-like [Na/Fe] abundance ratios, which indicate that the bulge does
not contain helium-enhanced populations as observed in some globular
clusters. Helium enhancement is therefore not the likely explanation
for the double red-clump observed in the bulge. We confirm that bulge
stars mostly follow abundance trends observed in the disc. However,
this similarity is not confirmed across all elements and metallicity
regimes. The more metal-poor bulge population at [Fe/H]~←0.8 is
enhanced in the elements associated with core collapse supernovae
(SNeII). In addition, the [La/Eu] abundance ratio suggests higher
r-process contribution, and likely higher star formation in the bulge
compared to the disc. This highlights the complex evolution in the
bulge, which should be investigated further, both in terms of
modelling; and with additional observations of the inner Galaxy.
Description:
The details of data selection, observation, reduction, and analysis
for the stellar sample presented here have been discussed in Duong et
al. (2019MNRAS.486.3586D 2019MNRAS.486.3586D) (Paper I). Briefly, the majority of the
sample are red giant and red clump stars with confirmed bulge
membership from the ARGOS survey (Freeman et al. 2013MNRAS.428.3660F 2013MNRAS.428.3660F,
Cat. J/MNRAS/428/3660; Ness et al. 2013MNRAS.430..836N 2013MNRAS.430..836N). The 2MASS
Ks magnitude range of ARGOS stars is 11-14. Our sample also includes
15 bulge stars from the EMBLA survey (Howes et al.
2016MNRAS.460..884H 2016MNRAS.460..884H, Cat. J/MNRAS/460/884), which were added to help
increase the number of metal-poor stars. We were able to probe the
full metallicity range of the bulge, from [Fe/H]∼0.5 to [Fe/H]~-2. The
minor axis fields (l,b)=(0,-10); (0,-7.5), and (0,-5) were observed
with the HERMES spectrograph, at resolving power R∼28000. The four
wavelength intervals covered by HERMES are 4713-4903Å (blue CCD);
5648-5873Å (green CCD); 6478-6737Å (red CCD), and 7585-7887Å
(IR CCD).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1a.dat 518 202 Abundances catalogue for 202 red giant branch
and clump stars along the minor bulge axis at
latitude b=-5°
tableb1b.dat 460 315 Abundances catalogue for 315 red giant branch
and clump stars along the minor bulge axis at
latitude b=-7.5°
tableb1c.dat 518 300 Abundances catalogue for 300 red giant branch
and clump stars along the minor bulge axis at
latitude b=-10°
tableb2.dat 27 31 Lines and atomic data used to derive abundance
ratios in this work
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: tableb1a.dat tableb1c.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- ID 2MASS source identifier (HHMMSSSS+DDMMSSS)
18- 25 F8.4 deg RAdeg Right ascension (J2000)
27- 34 F8.4 deg DEdeg Declination (J2000)
36- 44 F9.4 K Teff Effective temperature
46- 63 F18.14 K e_Teff Error on Teff
65- 73 F9.7 [cm/s2] logg Surface gravity
75- 93 F19.17 [cm/s2] e_logg Error on logg
95-116 F22.19 [-] [Fe/H] Iron to hydrogen abundance ratio
118-136 F19.17 [-] e_[Fe/H] Error on [Fe/H]
138-150 F13.10 [-] [Na/Fe] ? Na to iron abundance ratio
152-163 F12.10 [-] e_[Na/Fe] ? Error on [Na/Fe]
165-177 F13.10 [-] [Al/Fe] ? Al to iron abundance ratio
179-191 F13.11 [-] e_[Al/Fe] ? Error on [Al/Fe]
193-205 F13.10 [-] [Sc/Fe] ? Sc to iron abundance ratio
207-220 F14.12 [-] e_[Sc/Fe] ? Error on [Sc/Fe]
222-234 F13.10 [-] [Cr/Fe] ? Cr to iron abundance ratio
236-255 F20.18 [-] e_[Cr/Fe] ? Error on [Cr/Fe]
257-269 F13.10 [-] [Mn/Fe] ? Mn to iron abundance ratio
271-283 F13.11 [-] e_[Mn/Fe] ? Error on [Mn/Fe]
285-297 F13.10 [-] [Co/Fe] ? Co to iron abundance ratio
299-310 F12.10 [-] e_[Co/Fe] ? Error on [Co/Fe]
312-324 F13.10 [-] [Ni/Fe] ? Ni to iron abundance ratio
326-345 F20.18 [-] e_[Ni/Fe] ? Error on [Ni/Fe]
347-359 F13.10 [-] [Cu/Fe] ? Cu to iron abundance ratio
361-372 F12.10 [-] e_[Cu/Fe] ? Error on [Cu/Fe]
374-386 F13.10 [-] [Zr/Fe] ? Zr to iron abundance ratio
388-400 F13.11 [-] e_[Zr/Fe] ? Error on [Zr/Fe]
402-414 F13.10 [-] [La/Fe] ? La to iron abundance ratio
416-429 F14.12 [-] e_[La/Fe] ? Error on [La/Fe]
431-443 F13.10 [-] [Ce/Fe] ? Ce to iron abundance ratio
445-456 F12.10 [-] e_[Ce/Fe] ? Error on [Ce/Fe]
458-470 F13.10 [-] [Nd/Fe] ? Nd to iron abundance ratio
472-491 F20.18 [-] e_[Nd/Fe] ? Error on [Nd/Fe]
493-505 F13.10 [-] [Eu/Fe] ? Eu to iron abundance ratio
507-518 F12.10 [-] e_[Eu/Fe] ? Error on [Eu/Fe]
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Byte-by-byte Description of file: tableb1b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- ID 2MASS source identifier (HHMMSSSS+DDMMSSS)
18- 25 F8.4 deg RAdeg Right ascension (J2000)
27- 34 F8.4 deg DEdeg Declination (J2000)
36- 44 F9.4 K Teff Effective temperature
46- 63 F18.14 K e_Teff Error on Teff3
65- 73 F9.7 [cm/s2] logg Surface gravity
75- 93 F19.17 [cm/s2] e_logg Error on logg3
95-116 F22.19 [-] [Fe/H] Iron to hydrogen abundance ratio
118-136 F19.17 [-] e_[Fe/H] Error on [Fe/H]
138-148 F11.8 [-] [Na/Fe] ? Na to iron abundance ratio
150-158 F9.7 [-] e_[Na/Fe] ? Error on [Na/Fe]
160-170 F11.8 [-] [Al/Fe] ? Al to iron abundance ratio
172-181 F10.8 [-] e_[Al/Fe] ? Error on [Al/Fe]
183-193 F11.8 [-] [Sc/Fe] ? Sc to iron abundance ratio
195-205 F11.9 [-] e_[Sc/Fe] ? Error on [Sc/Fe]
207-217 F11.8 [-] [Cr/Fe] ? Cr to iron abundance ratio
219-238 F20.18 [-] e_[Cr/Fe] ? Error on [Cr/Fe]
240-249 F10.7 [-] [Mn/Fe] ? Mn to iron abundance ratio
251-260 F10.8 [-] e_[Mn/Fe] ? Error on [Mn/Fe]
262-272 F11.8 [-] [Co/Fe] ? Co to iron abundance ratio
274-282 F9.7 [-] e_[Co/Fe] ? Error on [Co/Fe]
284-294 F11.8 [-] [Ni/Fe] Ni to iron abundance ratio
296-315 F20.18 [-] e_[Ni/Fe] Error on [Ni/Fe]
317-327 F11.8 [-] [Cu/Fe] ? Cu to iron abundance ratio
329-337 F9.7 [-] e_[Cu/Fe] ? Error on [Cu/Fe]
339-349 F11.8 [-] [Zr/Fe] ? Zr to iron abundance ratio
351-360 F10.8 [-] e_[Zr/Fe] ? Error on [Zr/Fe]
362-372 F11.8 [-] [La/Fe] ? La to iron abundance ratio
374-383 F10.8 [-] e_[La/Fe] ? Error on [La/Fe]
385-395 F11.8 [-] [Ce/Fe] ? Ce to iron abundance ratio
397-405 F9.7 [-] e_[Ce/Fe] ? Error on [Ce/Fe]
407-417 F11.8 [-] [Nd/Fe] ? Nd to iron abundance ratio
419-438 F20.18 [-] e_[Nd/Fe] ? Error on [Nd/Fe]
440-450 F11.8 [-] [Eu/Fe] ? Eu to iron abundance ratio
452-460 F9.7 [-] e_[Eu/Fe] ? Error on [Eu/Fe]
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Species Lines used to derive abundance ratios
6- 14 F9.4 0.1nm lambda Wavelenght (Å)
16- 21 F6.3 [-] loggf Logarithm of oscillator strength
23- 27 F5.3 eV EP Excitation potential
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History:
From electronic version of the journal
References:
Duong et al., Paper I 2019MNRAS.486.3586D 2019MNRAS.486.3586D
(End) Ana Fiallos [CDS] 02-Nov-2022