J/ApJ/925/36 GC intrinsic iron abund. spreads. II. Milky Way (Bailin+, 2022)
Globular cluster intrinsic iron abundance spreads.
II. Protocluster metallicities and the age-metallicity relations of Milky Way
progenitors.
Bailin J., von Klar R.
<Astrophys. J., 925, 36 (2022)>
=2022ApJ...925...36B 2022ApJ...925...36B
ADC_Keywords: Clusters, globular; Milky Way; Abundances, [Fe/H]
Keywords: Milky Way Galaxy ; Globular star clusters ; Milky Way formation
Abstract:
Intrinsic iron abundance spreads in globular clusters (GCs), although
usually small, are very common, and are signatures of self-enrichment:
some stars within the cluster have been enriched by supernova ejecta
from other stars within the same cluster. We use the
Bailin (2018ApJ...863...99B 2018ApJ...863...99B) self-enrichment model to predict the
relationship between properties of the protocluster-its mass and the
metallicity of the protocluster gas cloud-and the final observable
properties today-its current metallicity and the internal iron
abundance spread. We apply this model to an updated catalog of Milky
Way GCs where the initial mass and/or the iron abundance spread is
known to reconstruct their initial metallicities. We find that with
the exception of the known anomalous bulge cluster Terzan 5 and three
clusters strongly suspected to be nuclear star clusters from stripped
dwarf galaxies, the model provides a good lens for understanding their
iron spreads and initial metallicities. We then use these initial
metallicities to construct age-metallicity relations for kinematically
identified major accretion events in the Milky Way's history. We find
that using the initial metallicity instead of the current metallicity
does not alter the overall picture of the Milky Way's history because
the difference is usually small but does provide information that can
help distinguish which accretion event some individual GCs with
ambiguous kinematics should be associated with and points to potential
complexity within the accretion events themselves.
Description:
We have updated the B19 catalog (Paper I; Bailin 2019, J/ApJS/245/5)
using new results from Marino+ (2019, J/ApJ/887/91), who obtained VLT
FLAMES-UVES spectra for 18 additional stars in NGC 3201;
Villanova+ (2019ApJ...882..174V 2019ApJ...882..174V) and
Romero-Colmenares+ (2021A&A...652A.158R 2021A&A...652A.158R), who analyzed 9 and 11 stars,
respectively, for FSR 1758; and Meszaros+ (2020, J/MNRAS/492/1641),
who updated the APOGEE measurements from Masseron+ (2019, J/A+A/622/A191)
with data from APOGEE-South.
Note that high-quality spectroscopic abundances for stars in NGC 1261
and NGC 6934 have recently been obtained (Marino+ 2021ApJ...923...22M 2021ApJ...923...22M
and Munoz+ 2021MNRAS.506.4676M 2021MNRAS.506.4676M).
See Section 3.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 126 146 Observed and predicted properties of the GC sample
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See also:
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
J/A+A/505/117 : Abundances of red giants in 15 GCs (Carretta+, 2009)
J/A+A/533/A69 : Spectroscopy of 124 RGB stars in NGC 1851 (Carretta+, 2011)
J/ApJ/726/L20 : Spectroscopy of Terzan 5 (Origlia+, 2011)
J/ApJ/795/22 : Iron abundance of Terzan 5 stars (Massari+, 2014)
J/MNRAS/450/815 : Red giants in NGC 5286 (Marino+, 2015)
J/A+A/592/A66 : NGC 2808 AGB and RGB stars Na abundance (Wang+, 2016)
J/ApJ/844/164 : HST astro-phot. analysis of NGC5139. III. (Bellini+, 2017)
J/AJ/154/155 : Abundances in the outer halo GC NGC 6229 (Johnson+, 2017)
J/A+A/607/A135 : NGC 104, 6121 & 6809 AGB & RGB Na abundances (Wang+, 2017)
J/MNRAS/474/2479 : Orbital parameters of globular clusters (Balbinot+, 2018)
J/ApJS/245/5 : Paper I - GC intrinsic iron abundance spreads (Bailin, 2019)
J/ApJ/887/91 : EWs of giants in the GC NGC3201 (Marino+, 2019)
J/A+A/622/A191 : 885 globular cluster giants abundances (Masseron+, 2019)
J/MNRAS/492/1641 : APOGEE southern GCs with the BACCHUS code (Meszaros+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Cluster identifier (1)
11- 19 A9 --- AName Alternate identifier
21- 24 F4.2 [Msun] logMinit [3.7/6.7] Log initial cluster stellar
mass (2)
26- 29 F4.2 [Msun] E_logMinit [0/0.12] Upper uncertainty in logMinit
31- 34 F4.2 [Msun] e_logMinit [0/0.18] Lower uncertainty in logMinit
36- 41 F6.3 [Sun] [Fe/H] [-2.3/-0.09] Adopted metallicity (3)
43- 46 F4.2 [Sun] e_[Fe/H] [0.1/0.2] Uncertainty in [Fe/H]
48- 52 F5.3 --- sigma0 [0/0.3]? Internal iron spread
54- 58 F5.3 --- E_sigma0 [0.002/0.14]? Upper uncertainty in sigma0
60- 64 F5.3 --- e_sigma0 [0/0.021]? Lower uncertainty in sigma0
66- 70 F5.3 --- sigma0-P [0/0.34] Predicted sigma0 value from
GCZCSE model (Bailin 2018ApJ...863...99B 2018ApJ...863...99B)
72- 76 F5.3 --- E_sigma0-P [0/0.2]? Upper uncertainty in sigma0-P
78- 82 F5.3 --- e_sigma0-P [0/0.12]? Lower uncertainty in sigma0-P
84- 88 F5.2 [Sun] [Fe/H]sig0 [-2.32/-0.15]? Reconstructed initial
metallicity from sigma0
90- 93 F4.2 [Sun] E_[Fe/H]sig0 [0.07/0.2]? Upper uncertainty in [Fe/H]sig0
95- 98 F4.2 [Sun] e_[Fe/H]sig0 [0.09/0.3]? Lower uncertainty in [Fe/H]sig0
100- 104 F5.2 [Sun] [Fe/H]Minit [-3.3/-0.09] Reconstructed initial
metallicity from Minit
106- 109 F4.2 [Sun] E_[Fe/H]Minit [0.09/0.6] Upper uncertainty in [Fe/H]Minit
111- 114 F4.2 [Sun] e_[Fe/H]Minit [0.09/1.2] Lower uncertainty in [Fe/H]Minit
116- 126 A11 --- Progen Proposed progenitor
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Note (1): NGC 6528, NGC 6553, Pal 1, and Pal 10 all have NaN values for their
uncertainties in sigmaP0. Terzan 5 has NaN values for its
uncertainties in sigmaP0 and the [Fe/H]-Minit values.
Note (2): From Balbinot & Gieles (2018, J/MNRAS/474/2479).
Note (3): [Fe/H] values have been taken from Kruijssen+ (2019MNRAS.486.3180K 2019MNRAS.486.3180K)
where available in order to maximize the homogeneity of the values.
For the remaining clusters, we used the values derived in B19 (Paper I;
Bailin 2019, J/ApJS/245/5) when available or from
Harris (1996, VII/195) (2010 edition) otherwise. For FSR 1758, we used
the [Fe/H] value obtained by our analysis, and used the current mass
estimate by Romero-Colmenares+ (2021A&A...652A.158R 2021A&A...652A.158R) as a lower limit;
given that this cluster lies within the bulge, it is likely that it
experienced a large amount of tidal stripping and so Minit is
significantly larger. See Section 3.1.
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History:
From electronic version of the journal
References:
Bailin et al. Paper I. 2019ApJS..245....5B 2019ApJS..245....5B Cat. J/ApJS/245/5
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Aug-2023