J/ApJ/925/66 Abundances of Sculptor dSph stars (de los Reyes+, 2022)
Simultaneous constraints on the star formation history and nucleosynthesis of
Sculptor dSph.
de los Reyes M.A.C., Kirby E.N., Ji A.P., Nunez E.H.
<Astrophys. J., 925, 66 (2022)>
=2022ApJ...925...66D 2022ApJ...925...66D
ADC_Keywords: Abundances; Galaxies, dwarf; Models; Spectra, optical
Keywords: Dwarf galaxies ; Dwarf spheroidal galaxies ;
Sculptor dwarf elliptical galaxy ; Star formation ; Nucleosynthesis ;
Stellar nucleosynthesis ; Galaxies ; Galaxy spectroscopy
Abstract:
We demonstrate that using up to seven stellar abundance ratios can
place observational constraints on the star formation histories (SFHs)
of Local Group dSphs, using Sculptor dSph as a test case. We use a
one-zone chemical evolution model to fit the overall abundance
patterns of α elements (which probe the core-collapse supernovae
that occur shortly after star formation), s-process elements (which
probe AGB nucleosynthesis at intermediate delay times), and iron-peak
elements (which probe delayed Type Ia supernovae). Our best-fit model
indicates that Sculptor dSph has an ancient SFH, consistent with
previous estimates from deep photometry. However, we derive a total
star formation duration of ∼0.9Gyr, which is shorter than
photometrically derived SFHs. We explore the effect of various model
assumptions on our measurement and find that modifications to these
assumptions still produce relatively short SFHs of duration ≲1.4Gyr.
Our model is also able to compare sets of predicted nucleosynthetic
yields for supernovae and AGB stars, and can provide insight into the
nucleosynthesis of individual elements in Sculptor dSph. We find that
observed [Mn/Fe] and [Ni/Fe] trends are most consistent with sub-MCh
Type Ia supernova models, and that a combination of "prompt" (delay
times similar to core-collapse supernovae) and "delayed" (minimum
delay times ≳50Myr) r-process events may be required to reproduce
observed [Ba/Mg] and [Eu/Mg] trends.
Description:
In this work, we primarily use literature abundances derived from
medium-resolution spectroscopy with the DEep Imaging Multi-Object
Spectrograph (DEIMOS) on the Keck II telescope. We compile several
abundance ratios from five catalogs (see Table 1).
We also use supplemental data from the Dwarf galaxy Abundances and
Radial-velocities Team (DART) survey (Tolstoy+ 2006Msngr.123...33T 2006Msngr.123...33T),
which used ESO VLT/FLAMES to obtain high-resolution (R≳20000) spectra
of RGB stars in dSphs.
Throughout this paper, we assume a flat ΛCDM cosmology with
Planck 2018 parameters (H0=67.4km/s/Mpc, Ωm=0.315).
Objects:
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RA (ICRS) DE Designation(s)
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01 00 09.39 -33 42 32.0 Sculptor dSph = NAME Scl dSph
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 150 465 Abundance catalog of Sculptor dSph stars
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See also:
J/ApJ/617/1091 : La and Eu abundances in 85 stars (Simmerer+, 2004)
J/ApJS/191/352 : Abundances in stars of MW dwarf satellites (Kirby+, 2010)
J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/ApJ/789/147 : Star formation histories of LG dwarf galaxies (Weisz+, 2014)
J/ApJ/801/125 : Carbon in red giants in GCs and dSph galaxies (Kirby+, 2015)
J/MNRAS/449/761 : EWs of metal-poor stars in UMi I dSph galaxy (Ural+, 2015)
J/ApJ/830/93 : Abundances of Ret II brightest red giant members (Ji+, 2016)
J/ApJ/834/9 : Sp. obs. of LeoA, Aqr & Sgr dwarf gal. (Kirby+, 2017)
J/ApJ/869/50 : Barium abundances of red giant branch stars (Duggan+, 2018)
J/ApJS/237/18 : Cr, Co & Ni abund. for metal-poor red giants (Kirby+, 2018)
J/ApJS/237/13 : Yields of 13-120M☉ massive stars (Limongi+, 2018)
J/A+A/631/A80 : Mn lines NLTE formation in late-type stars (Bergemann+, 2019)
J/A+A/631/A171 : Neutron-capture elements in dwarf gal. (Skuladottir+, 2019)
J/A+A/626/A15 : Sculptor Red Giant Branch stars abundances (Hill+, 2019)
J/ApJ/891/85 : Manganese abund. in GC & dSph galaxies (de los Reyes+, 2020)
J/ApJ/913/53 : Gas content of galaxies within 2Mpc of the MW (Putman+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Survey Spectroscopic survey (1)
8- 14 A7 --- ID ID of star (from Kirby+ 2010, J/ApJS/191/352
or Hill+ 2019, J/A+A/626/A15)
17- 17 I1 h RAh [0/1] Hour of Right Ascension (J2000)
19- 20 I2 min RAm Minute of Right Ascension (J2000)
22- 26 F5.2 s RAs Second of Right Ascension (J2000)
28 A1 - DE- [-] Sign of Declination (J2000)
30- 31 I2 deg DEd [33] Degree of Declination (J2000)
33- 34 I2 arcmin DEm [30/52] Arcminute of Declination (J2000)
36- 40 F5.2 arcsec DEs Arcsecond of Declination (J2000)
42- 46 F5.2 [Sun] [Fe/H] [-3.9/-0.89] Iron logarithmic abundance
relative to the Sun
48- 51 F4.2 [Sun] e_[Fe/H] [0.1/0.6] Uncertainty in [Fe/H]
53- 57 F5.2 [Sun] [Mg/Fe] [-0.7/1.2]? Magnesium-to-iron logarithmic
ratio relative to the Sun
59- 62 F4.2 [Sun] e_[Mg/Fe] [0.1/1]? Uncertainty in [Mg/Fe]
64- 68 F5.2 [Sun] [Si/Fe] [-0.6/1.4]? Silicon-to-iron logarithmic
ratio relative to the Sun
70- 73 F4.2 [Sun] e_[Si/Fe] [0.1/1]? Uncertainty in [Si/Fe]
75- 79 F5.2 [Sun] [Ca/Fe] [-0.7/1.2]? Calcium-to-iron logarithmic
ratio relative to the Sun
81- 84 F4.2 [Sun] e_[Ca/Fe] [0.03/1]? Uncertainty in [Ca/Fe]
86- 90 F5.2 [Sun] [C/Fe] [-1.1/0.7]? Carbon-to-iron logarithmic ratio
relative to the Sun
92- 95 F4.2 [Sun] e_[C/Fe] [0.3/0.5]? Uncertainty in [C/Fe]
97- 101 F5.2 [Sun] [Mn/Fe] [-0.9/0.7]? Manganese-to-iron logarithmic
ratio relative to the Sun
103- 106 F4.2 [Sun] e_[Mn/Fe] [0.03/0.5]? Uncertainty in [Mn/Fe]
108- 112 F5.2 [Sun] [Ni/Fe] [-1.4/0.6]? Nickel-to-iron logarithmic ratio
relative to the Sun
114- 117 F4.2 [Sun] e_[Ni/Fe] [0.09/0.4]? Uncertainty in [Ni/Fe]
119- 123 F5.2 [Sun] [Ba/Fe] [-1.7/1.6]? Barium-to-iron logarithmic ratio
relative to the Sun
125- 128 F4.2 [Sun] e_[Ba/Fe] [0.16/0.5]? Uncertainty in [Ba/Fe]
130- 134 F5.2 [Sun] [Ba/Fe]s [-3.4/1.1]? S-process Barium-to-iron
logarithmic ratio relative to the Sun (2)
136- 139 F4.2 [Sun] e_[Ba/Fe]s [0.16/0.5]? Uncertainty in [Ba/Fe]s
141- 145 F5.2 [Sun] [Eu/Fe] [-0.22/0.9]? Europium-to-iron logarithmic
ratio relative to the Sun
147- 150 F4.2 [Sun] e_[Eu/Fe] [0.19/0.4]? Uncertainty in [Eu/Fe]
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Note (1): Survey as follows:
DEIMOS = The DEIMOS abundances are compiled from a number of sources:
[Fe/H], [Mg/Fe], [Si/Fe], [Ca/Fe] - Kirby+ (2010, J/ApJS/191/352)
[C/Fe] - Kirby+ (2015, J/ApJ/801/125)
[Ni/Fe] - Kirby+ (2018, J/ApJS/237/18)
[Mn/Fe] - de los Reyes+ (2020, J/ApJ/891/85)
[Ba/Fe] - Duggan+ (2018, J/ApJ/869/50)
DART = The DART abundances are from Hill+ (2019, J/A+A/626/A15),
except for [Mn/Fe], which are from North+ (2012A&A...541A..45N 2012A&A...541A..45N).
Note (2): The s-process contribution to [Ba/Fe] is estimated using Equation 1
as described in the text.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-Aug-2023