J/A+A/689/A201 Pristine Inner Galaxy Survey. IX. (Sestito+, 2024)
The Pristine Inner Galaxy Survey (PIGS) IX. The largest detailed chemical
analysis of very metal-poor stars in the Sagittarius dwarf galaxy.
Sestito F., Vitali S., Jofre P., Venn K.A., Aguado D.S., Aguilera-Gomez C.,
Ardern-Arentsen A., de Brito Silva D., Carlberg R., Eldridge C.J.L.,
Gran F., Hill V., Jablonka P., Kordopatis G., Martin N.F., Matsuno T.,
Rusterucci S., Starkenburg E., Viswanathan A.
<Astron. Astrophys. 689, A201 (2024)>
=2024A&A...689A.201S 2024A&A...689A.201S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Stars, metal-deficient ; Abundances ; Optical
Keywords: stars: abundances - stars: Population II - galaxies: abundances -
galaxies: dwarf - galaxies: individual: Sagittarius dwarf galaxy
Abstract:
The most metal-poor stars provide valuable insights into the early
chemical enrichment history of a system, carrying the chemical
imprints of the first generations of supernovae. The most metal-poor
region of the Sagittarius dwarf galaxy remains inadequately observed
and characterised. To date, only 4 stars with [Fe/H]←2.0 have been
chemically analysed with high-resolution spectroscopy. In this study,
we present the most extensive chemical abundance analysis of 12
low-metallicity stars with metallicities down to [Fe/H]=-3.26 and
located in the main body of Sagittarius. These targets, selected from
the Pristine Inner Galaxy Survey, were observed using the MIKE
high-resolution spectrograph at the Magellan-Clay telescope, which
allowed us to measure up to 17 chemical species. The chemical
composition of these stars reflects the imprint of a variety of type
II supernovae (SNe II). A combination of low- to intermediate-mass
highenergy SNe and hypernovae (∼10-70M☉) is required to account
for the abundance patterns of the lighter elements up to the Fe-peak.
The trend of the heavy elements suggests the involvement of compact
binary merger events and fast-rotating (up to 300km/s)
intermediate-mass to massive metal-poor stars (∼25-120M☉) that
are the sources of rapid and slow processes, respectively.
Additionally, asymptotic giant branch stars contribute to a wide
dispersion of [Ba/Mg] and [Ba/Eu]. The absence of an -knee in our data
indicates that type Ia supernovae did not contribute in the very
metal-poor region ([Fe/H]≤-2.0). However, they might have started to
pollute the interstellar medium at [Fe/H]>-2.0, given the relatively
low [Co/Fe] in this metallicity region.
Description:
The very metal-poor region of the Sagittarius dwarf galaxy
has so far been poorly investigated. In this work, we provide the
first and most detailed chemical abundance analysis for 12 stars,
shedding light on the chemical evolution of this system.
The targets were previously observed with AAT medium-resolution within
the Pristine Inner Galaxy survey (Arentsen et al.,
2020MNRAS.496.4964A 2020MNRAS.496.4964A). Precise radial velocities and chemical
abundances of up to 17 species are measured from the high-resolution
spectra of the MIKE spectrograph at the Magellan-Clay telescope.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 106 12 Pristine names, Gaia informations, and
log of the observations
table2.dat 55 12 Stellar parameters
xhstpa.dat 563 12 [X/H] stellar parameters
xfestpa.dat 827 12 [X/Fe] stellar parameters
moog.txt 98 3726 MOOG output files merged in a single ASCII file
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See also:
J/MNRAS/530/3391 : PIGS VIII (Ardern-Arentsen+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- SName Short name (PHHMMSS+DDMMSS)
16- 42 A27 --- PIGS PIGS name (Pristine_HHMMSs.ss+DDMMSS.s)
44- 62 I19 --- GaiaDR3 Gaia DR3 source id
64- 72 F9.5 deg RAdeg right ascension (J2000)
74- 82 F9.5 deg DEdeg Declination (J2000)
84- 88 F5.2 mag Gmag Gaia DR3 G magnitude
90- 93 F4.2 mag BP-RP Gaia DR3 BP-RP colour index
95- 98 F4.2 mag AV Reddening (G1)
100-103 I4 s Texp Total exposure time
105-106 I2 --- S/N S/N at the MgI Triplet region (∼5180Å)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- SName Short name (PHHMMSS+DDMMSS)
16- 21 F6.2 km/s RV Radial velocity
23- 26 F4.2 km/s e_RV Radial velocity error
28- 31 I4 K Teff Effective temperature
33- 34 I2 K e_Teff Effective temperature error
36- 39 F4.2 [cm/s2] logg Surface gravity
41- 44 F4.2 [cm/s2] e_logg Surface gravity error
46- 50 F5.2 [-] [Fe/H] Metallicity
52- 55 F4.2 [-] e_[Fe/H] Metallicity error
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Byte-by-byte Description of file: xhstpa.dat
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Bytes Format Units Label Explanations
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1- 27 A27 --- PIGS PIGS name (Pristine_HHMMSs.ss+DDMMSS.s)
29- 47 F19.16 --- FeI Abundance FeI
49- 53 F5.3 --- s_FeI Dispersion on FeI
55- 57 I3 --- o_FeI [11/188] Number of lines for element FeI
59- 64 F6.3 --- FeII ?=- Abundance FeII
66- 70 F5.3 --- s_FeII ?=- Dispersion on FeII
72- 74 I3 --- o_FeII [0/25]?=- Number of lines for element FeII
76- 94 F19.16 --- NaI Abundance NaI
96-100 F5.3 --- s_NaI Dispersion on NaI
102 I1 --- o_NaI [2/5] Number of lines for element NaI
104-122 F19.16 --- MgI Abundance MgI
124-128 F5.3 --- s_MgI Dispersion on MgI
130 I1 --- o_MgI [2/7] Number of lines for element MgI
132-137 F6.3 --- AlI ?=- Abundance AlI
139-143 F5.3 --- s_AlI ?=- Dispersion on AlI
145-147 I3 --- o_AlI [0/2]?=- Number of lines for element AlI
149-167 F19.16 --- SiI ?=- Abundance SiI
169-173 F5.3 --- s_SiI ?=- Dispersion on SiI
175-177 I3 --- o_SiI [1/10]?=-Number of lines for element SiI
179-184 F6.3 --- KI ?=-9.99 Abundance KI
186-191 F6.3 --- s_KI ?=-9.99 Dispersion on KI
193-195 F3.1 --- o_KI [0/2] Number of lines for element KI
197-202 F6.3 --- CaI Abundance CaI
204-208 F5.3 --- s_CaI Dispersion on CaI
210-211 I2 --- o_CaI [3/23] Number of lines for element CaI
213-231 F19.16 --- ScII ?=- Abundance ScII
233-237 F5.3 --- s_ScII ?=- Dispersion on ScII
239-241 I3 --- o_ScII [0/8]?=- Number of lines for element ScII
243-248 F6.3 --- TiI ?=- Abundance TiI
250-254 F5.3 --- s_TiI ?=- Dispersion on TiI
256-258 I3 --- o_TiI [2/21]?=-Number of lines for element TiI
260-278 F19.16 --- TiII ?=- Abundance TiII
280-284 F5.3 --- s_TiII ?=- Dispersion on TiII
286-288 I3 --- o_TiII [0/37]?=-Number of lines for element TiII
290-308 F19.16 --- CrI Abundance CrI
310-314 F5.3 --- s_CrI Dispersion on CrI
316-317 I2 --- o_CrI [1/11]Number of lines for element CrI
319-337 F19.16 --- MnI ?=- Abundance MnI
339-343 F5.3 --- s_MnI ?=- Dispersion on MnI
345-347 I3 --- o_MnI [0/7]?=-Number of lines for element MnI
349-367 F19.16 --- CoI ?=- Abundance CoI
369-373 F5.3 --- s_CoI ?=- Dispersion on CoI
375-377 I3 --- o_CoI [0/4]?=-Number of lines for element CoI
379-397 F19.16 --- NiI Abundance NiI
399-403 F5.3 --- s_NiI Dispersion on NiI
405-406 I2 --- o_NiI [1/11] Number of lines for element NiI
408-426 F19.16 --- ZnI ?=- Abundance ZnI
428-432 F5.3 --- s_ZnI ?=- Dispersion on ZnI
434-436 I3 --- o_ZnI [0/2]?=- Number of lines for element ZnI
438-443 F6.3 --- SrII ?=- Abundance SrII
445-449 F5.3 --- s_SrII ?=- Dispersion on SrII
451-453 I3 --- o_SrII [0/2]?=- Number of lines for element SrII
455-473 F19.16 --- YII ?=- Abundance YII
475-479 F5.3 --- s_YII ?=- Dispersion on YII
481-483 I3 --- o_YII [0/5]?=- Number of lines for element YII
485-490 F6.3 --- BaII Abundance BaII
492-496 F5.3 --- s_BaII Dispersion on BaII
498 I1 --- o_BaII [2/5] Number of lines for element BaII
500-505 F6.3 --- [Fe/H]F FERRE [Fe/H]
507-512 F6.4 --- AV ?=- Reddening (G1)
514-524 F11.6 K Teff Effective temperature
526-536 F11.8 K e_Teff Effective temperature error
538-549 F12.10 [cm/s2] logg Surface gravity
551-563 F13.11 [cm/s2] e_logg Surface gravity error
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Byte-by-byte Description of file: xfestpa.dat
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Bytes Format Units Label Explanations
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1- 27 A27 --- PIGS PIGS name (Pristine_HHMMSs.ss+DDMMSS.s)
29- 47 F19.16 --- [Fe/H] Abundance [Fe/H]
49- 68 F20.18 --- e_[Fe/H] rms uncertainty on [Fe/H]
70- 74 F5.2 --- [C/Fe] ?=-9.99 Abundance [C/Fe]
76- 80 F5.2 --- [C/Fe]c ?=-9.99 Corrected abundance [C/Fe]
82-102 F21.18 --- [Na/Fe] Abundance [Na/Fe]
104-123 F20.18 --- e_[Na/Fe] rms uncertainty on [Na/Fe]
125-143 F19.17 --- [Mg/Fe] Abundance [Mg/Fe]
145-164 F20.18 --- e_[Mg/Fe] rms uncertainty on [Mg/Fe]
166-185 F20.17 --- [Al/Fe] ?=-9.99 Abundance [Al/Fe]
187-207 F21.18 --- e_[Al/Fe] ?=-9.99 rms uncertainty on [Al/Fe]
209-228 F20.17 --- [Si/Fe] ?=-9.99 Abundance [Si/Fe]
230-250 F21.18 --- e_[Si/Fe] ?=-9.99 rms uncertainty on [Si/Fe]
252-271 F20.17 --- [K/Fe] Abundance [K/Fe]
273-292 F20.18 --- e_[K/Fe] rms uncertainty on [K/Fe]
294-312 F19.17 --- [Ca/Fe] Abundance [Ca/Fe]
314-333 F20.18 --- e_[Ca/Fe] rms uncertainty on [Ca/Fe]
335-354 F20.17 --- [Sc/Fe] ?=-9.99 Abundance [Sc/Fe]
356-375 F20.17 --- e_[Sc/Fe] ?=-9.99 rms uncertainty on [Sc/Fe]
377-396 F20.17 --- [Ti/Fe] ?=-9.99 Abundance [Ti/Fe]
398-418 F21.18 --- e_[Ti/Fe] ?=-9.99 rms uncertainty on [Ti/Fe]
420-439 F20.17 --- [Cr/Fe] Abundance [Cr/Fe]
441-460 F20.18 --- e_[Cr/Fe] rms uncertainty on [Cr/Fe]
462-481 F20.17 --- [Mn/Fe] ?=-9.99 Abundance [Mn/Fe]
483-503 F21.18 --- e_[Mn/Fe] ?=-9.99 rms uncertainty on [Mn/Fe]
505-525 F21.18 --- [Co/Fe] ?=-9.99 Abundance [Co/Fe]
527-547 F21.18 --- e_[Co/Fe] ?=-9.99 rms uncertainty on [Co/Fe]
549-570 F22.19 --- [Ni/Fe] Abundance [Ni/Fe]
572-591 F20.18 --- e_[Ni/Fe] rms uncertainty on [Ni/Fe]
593-612 F20.17 --- [Zn/Fe] ?=-9.99 Abundance [Zn/Fe]
614-634 F21.18 --- e_[Zn/Fe] ?=-9.99 rms uncertainty on [Zn/Fe]
636-655 F20.17 --- [Sr/Fe] ?=-9.99 Abundance [Sr/Fe]
657-676 F20.17 --- e_[Sr/Fe] ?=-9.99 rms uncertainty on [Sr/Fe]
678-698 F21.18 --- [Y/Fe] ?=-9.99 Abundance [Y/Fe]
700-720 F21.18 --- e_[Y/Fe] ?=-9.99 rms uncertainty on [Y/Fe]
722-743 F22.19 --- [Ba/Fe] Abundance [Ba/Fe]
745-764 F20.18 --- e_[Ba/Fe] rms uncertainty on [Ba/Fe]
766-770 F5.2 --- [Eu/Fe] ?=-9.99 Abundance [Eu/Fe]
772-776 F5.2 --- e_[Eu/Fe] ?=-9.99 rms uncertainty on [Eu/Fe]
778-788 F11.6 K Teff Effective temperature
790-800 F11.8 K e_Teff Effective temperature error
802-813 F12.10 [cm/s2] logg Surface gravity
815-827 F13.11 [cm/s2] e_logg Surface gravity error
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Global notes:
Note (G1): Reddening from Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S) and
updated by Schlafly & Finkbeiner (2011ApJ...737..103S 2011ApJ...737..103S).
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Acknowledgements:
Federico Sestito, sestitof(at)uvic.ca
References:
Arentsen et al., Paper II 2020MNRAS.496.4964A 2020MNRAS.496.4964A
Arentsen et al., Paper I 2020MNRAS.491L..11A 2020MNRAS.491L..11A
Arentsen et al., Paper III 2021MNRAS.505.1239A 2021MNRAS.505.1239A
Vitali et al., Paper IV 2022MNRAS.517.6121V 2022MNRAS.517.6121V
Sestito et al., Paper V 2023MNRAS.518.4557S 2023MNRAS.518.4557S
Zhao et al., Paper VI 2023MNRAS.519..754Z 2023MNRAS.519..754Z
Mashonkina et al., Paper VII 2023MNRAS.523.2111M 2023MNRAS.523.2111M
Ardern-Arentsen et al., Paper VIII 2024MNRAS.530.3391A 2024MNRAS.530.3391A, Cat. J/MNRAS/530/3391
(End) Patricia Vannier [CDS] 29-Aug-2024