J/MNRAS/513/1557 Accreted halo stars abundances (Carrillo+, 2022)
The detailed chemical abundance patterns of accreted halo stars from
the optical to infrared.
Carrillo A., Hawkins K., Jofre P., de Brito Silva D., Das P., Lucey M.
<Mon. Not. R. Astron. Soc. 513, 1557-1580 (2022)>
=2022MNRAS.513.1557C 2022MNRAS.513.1557C (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, halo ; Abundances ; Optical
Keywords: stars: abundances - Galaxy: abundances - Galaxy: formation -
Galaxy: halo
Abstract:
Understanding the assembly of our Galaxy requires us to also
characterize the systems that helped build it. In this work, we
accomplish this by exploring the chemistry of accreted halo stars from
the Gaia-Enceladus/Gaia-Sausage (GES) selected in the infrared from
the Apache Point Observatory Galactic Evolution Experiment (APOGEE)
Data Release 16. We use high resolution optical spectra for 62 GES
stars to measure abundances in 20 elements spanning the α,
Fe-peak, light, odd-Z, and notably, the neutron-capture groups of
elements to understand their trends in the context of and in contrast
to the Milky Way and other stellar populations. Using these derived
abundances we find that the optical and the infrared abundances agree
to within 0.15 dex except for O, Co, Na, Cu, and Ce. These stars have
enhanced neutron- capture abundance trends compared to the Milky Way,
and their [Eu/Mg] and neutron-capture abundance ratios (e.g., [Y/Eu],
[Ba/Eu], [Zr/Ba], [La/Ba], and [Nd/Ba]) point to r-process enhancement
and a delay in s-process enrichment. Their [α/Fe] trend is lower
than the Milky Way trend for [Fe/H]>-1.5dex, similar to previous
studies of GES stars and consistent with the picture that these stars
formed in a system with a lower rate of star formation. This is
further supported by their depleted abundances in Ni, Na, and Cu
abundances, again, similar to previous studies of low-α stars
with accreted origins.
Description:
Abundances based on observations from MIKE Magellan and the Tull
Spectrograph at McDonald Observatory.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
main.dat 949 62 Stellar atmospheric parameters and abundances
of target sample
targets.dat 107 62 Observational properties of target sample
(table 1)
abund.dat 49 3917 Individual line abundances (table A1)
nlte.dat 259 62 NLTE corrections calculated using
https://nlte.mpia.de/gui-siuAC_secE.php
(table A2)
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
Byte-by-byte Description of file: main.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- APOGEE Object identification from APOGEE
20- 29 F10.6 deg RAdeg Right ascension (ICRS)
31- 40 F10.6 deg DEdeg Declination (ICRS)
42- 59 F18.13 K Teff Effective temperature
61- 77 F17.14 K e_Teff Error in effective temperature
79- 84 F6.4 [cm/s2] logg Surface gravity
86-105 F20.18 [cm/s2] e_logg Error in surface gravity
107-112 F6.3 [-] [Fe/H] Metallicity
114-118 F5.3 [-] e_[Fe/H] Error in metallicity
120-124 F5.3 km/s vmicro Microturbulence
126-130 F5.3 km/s e_vmicro Error in microturbulence
132-150 F19.17 [-] [O/Fe] ? Abundance [O/Fe]
152-154 F3.1 [-] e_[O/Fe] ? Abundance uncertainty in [O/Fe]
156 I1 --- o_[O/Fe] Number of O lines
158-179 F22.19 [-] [Na/Fe] ? Abundance [Na/Fe]
181-201 F21.19 [-] e_[Na/Fe] ? Abundance uncertainty in [Na/Fe]
203 I1 --- o_[Na/Fe] Number of Na lines
205-223 F19.17 [-] [Mg/Fe] ? Abundance [Mg/Fe]
225-244 F20.18 [-] e_[Mg/Fe] ? Abundance uncertainty in [Mg/Fe]
246 I1 --- o_[Mg/Fe] Number of Mg lines
248-268 F21.18 [-] [Si/Fe] Abundance [Si/Fe]
270-289 F20.18 [-] e_[Si/Fe] Abundance uncertainty in [Si/Fe]
291 I1 --- o_[Si/Fe] Number of Si lines
293-313 F21.18 [-] [Ca/Fe] Abundance [Ca/Fe]
315-334 F20.18 [-] e_[Ca/Fe] Abundance uncertainty in [Ca/Fe]
336-337 I2 --- o_[Ca/Fe] Number of Ca lines
339-360 F22.19 [-] [Sc/Fe] Abundance [Sc/Fe]
362-381 E20.12 [-] e_[Sc/Fe] Abundance uncertainty in [Sc/Fe]
383 I1 --- o_[Sc/Fe] Number of Sc lines
385-405 F21.18 [-] [V/Fe] ? Abundance [V/Fe]
407-427 F21.19 [-] e_[V/Fe] ? Abundance uncertainty in [V/Fe]
429 I1 --- o_[V/Fe] Number of V lines
431-452 F22.19 [-] [Cr/Fe] Abundance [Cr/Fe]
454-474 F21.19 [-] e_[Cr/Fe] Abundance uncertainty in [Cr/Fe]
476 I1 --- o_[Cr/Fe] Number of Cr lines
478-497 F20.17 [-] [Mn/Fe] ? Abundance [Mn/Fe]
499-519 F21.19 [-] e_[Mn/Fe] ? Abundance uncertainty in [Mn/Fe]
521 I1 --- o_[Mn/Fe] Number of Mn lines
523-543 F21.18 [-] [Co/Fe] ? Abundance [Co/Fe]
545-564 F20.18 [-] e_[Co/Fe] ? Abundance uncertainty in [Co/Fe]
566 I1 --- o_[Co/Fe] Number of Co lines
568-589 F22.19 [-] [Ni/Fe] Abundance [Ni/Fe]
591-610 F20.18 [-] e_[Ni/Fe] Abundance uncertainty in [Ni/Fe]
612 I1 --- o_[Ni/Fe] Number of Ni lines
614-634 F21.18 [-] [Cu/Fe] ? Abundance [Cu/Fe]
636-655 F20.18 [-] e_[Cu/Fe] ? Abundance uncertainty in [Cu/Fe]
657 I1 --- o_[Cu/Fe] Number of Cu lines
659-679 F21.18 [-] [Zn/Fe] Abundance [Zn/Fe]
681-683 F3.1 [-] e_[Zn/Fe] Abundance uncertainty in [Zn/Fe]
685 I1 --- o_[Zn/Fe] Number of Zn lines
687-708 E22.14 [-] [Y/Fe] ? Abundance [Y/Fe]
710-730 F21.19 [-] e_[Y/Fe] ? Abundance uncertainty in [Y/Fe]
732 I1 --- o_[Y/Fe] Number of Y lines
734-754 F21.18 [-] [Zr/Fe] ? Abundance [Zr/Fe]
756-775 F20.18 [-] e_[Zr/Fe] ? Abundance uncertainty in [Zr/Fe]
777 I1 --- o_[Zr/Fe] Number of Zr lines
779-800 F22.19 [-] [Ba/Fe] ? Abundance [Ba/Fe]
802-804 F3.1 [-] e_[Ba/Fe] ? Abundance uncertainty in [Ba/Fe]
806 I1 --- o_[Ba/Fe] Number of Ba lines
808-828 F21.18 [-] [La/Fe] ? Abundance [La/Fe]
830-850 F21.19 [-] e_[La/Fe] ? Abundance uncertainty in [La/Fe]
852 I1 --- o_[La/Fe] Number of La lines
854-873 F20.18 [-] [Ce/Fe] ? Abundance [Ce/Fe]
875-877 F3.1 [-] e_[Ce/Fe] ? Abundance uncertainty in [Ce/Fe]
879 I1 --- o_[Ce/Fe] Number of Ce lines
881-899 F19.17 [-] [Nd/Fe] Abundance [Nd/Fe]
901-921 F21.19 [-] e_[Nd/Fe] Abundance uncertainty in [Nd/Fe]
923 I1 --- o_[Nd/Fe] Number of Nd lines
925-943 F19.17 [-] [Eu/Fe] ? Abundance [Eu/Fe]
945-947 F3.1 [-] e_[Eu/Fe] ? Abundance uncertainty in [Eu/Fe]
949 I1 --- o_[Eu/Fe] Number of Eu lines
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Byte-by-byte Description of file: targets.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- APOGEE Object identification from APOGEE
20- 38 I19 --- GaiaDR2 Gaia DR2 source ID
40- 49 F10.6 deg RAdeg Right ascension (ICRS)
51- 60 F10.6 deg DEdeg Declination (ICRS)
62- 71 F10.7 mag Gmag Gaia G mag
73- 83 F11.6 km/s RV Radial velocity
85- 94 F10.8 km/s e_RV Error in radial velocity
96-107 F12.8 --- snropt signal-to-noise ratio in the optical spectra
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Byte-by-byte Description of file: abund.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- APOGEE Object identification from APOGEE
20- 21 A2 --- Element Element
23- 28 F6.1 nm lambda Wavelength
30- 36 F7.3 [-] log(gf) Oscillator strength
38- 42 F5.3 eV EP Excitation potential
44- 49 F6.3 [-] log(Abund) log(Nelement)/log(NH)
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Byte-by-byte Description of file: nlte.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- APOGEE Object identification from APOGEE
20- 21 I2 --- C6363.85 [0/30] NLTE correction for O I (6363.85nm)
23- 28 F6.3 --- C4571.09 NLTE correction for Mg I (4571.09nm)
30- 35 F6.3 --- C5711.07 NLTE correction for Mg I (5711.07nm)
37- 42 F6.3 --- C5665.6 NLTE correction for Si I (5665.6nm)
44- 49 F6.3 --- C5690.47 NLTE correction for Si I (5690.47nm)
51- 56 F6.3 --- C5701.14 NLTE correction for Si I (5701.14nm)
58- 63 F6.3 --- C5708.44 NLTE correction for Si I (5708.44nm)
65- 70 F6.3 --- C5772.15 NLTE correction for Si I (5772.15nm)
72- 77 F6.3 --- C5948.541 NLTE correction for Si I (5948.541nm)
79- 84 F6.3 --- C4789.546 NLTE correction for Cr I (4789.546nm)
86- 91 F6.3 --- C4936.34 NLTE correction for Cr I (4936.34nm)
93- 98 F6.3 --- C4964.93 NLTE correction for Cr I (4964.93nm)
100-105 F6.3 --- C5247.573 NLTE correction for Cr I (5247.573nm)
107-112 F6.3 --- C5272.002 NLTE correction for Cr I (5272.002nm)
114-119 F6.3 --- C5296.69 NLTE correction for Cr I (5296.69nm)
121-126 F6.3 --- C5345.81 NLTE correction for Cr I (5345.81nm)
128-133 F6.3 --- C5348.32 NLTE correction for Cr I (5348.32nm)
135-140 F6.3 --- C5409.79 NLTE correction for Cr I (5409.79nm)
142-147 F6.3 --- C4783.427 NLTE correction for Mn I (4783.427nm)
149-154 F6.3 --- C4823.505 NLTE correction for Mn I (4823.505nm)
156-161 F6.3 --- C5394.707 NLTE correction for Mn I (5394.707nm)
163-168 F6.3 --- C5420.265 NLTE correction for Mn I (5420.265nm)
170-175 F6.3 --- C5432.543 NLTE correction for Mn I (5432.543nm)
177-182 F6.3 --- C6013.517 NLTE correction for Mn I (6013.517nm)
184-189 F6.3 --- C6021.799 NLTE correction for Mn I (6021.799nm)
191-196 F6.3 --- C5212.686 NLTE correction for Co I (5212.686nm)
198-203 F6.3 --- C5301.04 NLTE correction for Co I (5301.04nm)
205-210 F6.3 --- C5331.46 NLTE correction for Co I (5331.46nm)
212-217 F6.3 --- C5352.05 NLTE correction for Co I (5352.05nm)
219-224 F6.3 --- C5369.59 NLTE correction for Co I (5369.59nm)
226-231 F6.3 --- C5530.78 NLTE correction for Co I (5530.78nm)
233-238 F6.3 --- C5590.72 NLTE correction for Co I (5590.72nm)
240-245 F6.3 --- C5647.23 NLTE correction for Co I (5647.23nm)
247-252 F6.3 --- C5915.55 NLTE correction for Co I (5915.55nm)
254-259 F6.3 --- C6771.04 NLTE correction for Co I (6771.04nm)
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Acknowledgements:
Andreia Carrillo, andreia.carrillo(at)durham.ac.uk
(End) Patricia Vannier [CDS] 27-Apr-2022