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Title: On Potassium and Other Abundance Anomalies of Red Giants In NGC 2419

Journal Article · · The Astrophysical Journal (Online)
 [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [4];  [4]
  1. Univ. of North Carolina, Chapel Hill, NC (United States); Duke Univ., Durham, NC (United States). Triangle Universities Nuclear Laboratory
  2. Australian National Univ., Canberra, ACT (Australia)
  3. Université P. & M. Curie, Paris (France). Inst. d'Astrophysique de Paris
  4. Monash Univ., Melbourne, VIC (Australia). Monash Centre for Astrophysics

Globular clusters are of paramount importance for testing theories of stellar evolution and early galaxy formation. Strong evidence for multiple populations of stars in globular clusters derives from observed abundance anomalies. A puzzling example is the recently detected Mg–K anticorrelation in NGC 2419. We perform Monte Carlo nuclear reaction network calculations to constrain the temperature–density conditions that gave rise to the elemental abundances observed in this elusive cluster. We find a correlation between stellar temperature and density values that provide a satisfactory match between simulated and observed abundances in NGC 2419 for all relevant elements (Mg, Si, K, Ca, Sc, Ti, and V). Except at the highest densities (ρ≳108 g cm-3), the acceptable conditions range from ≈100 MK at ≈108 g cm-3 to ≈200 MK at ≈10-4 g cm-3. This result accounts for uncertainties in nuclear reaction rates and variations in the assumed initial composition. We review hydrogen- burning sites and find that low-mass stars, asymptotic giant branch (AGB) stars, massive stars, or supermassive stars cannot account for the observed abundance anomalies in NGC 2419. Super-AGB stars could be viable candidates for the polluter stars if stellar model parameters can be fine-tuned to produce higher temperatures. Novae, involving either CO or ONe white dwarfs, could be interesting polluter candidates, but a current lack of low-metallicity nova models precludes firmer conclusions. We also discuss whether additional constraints for the first-generation polluters can be obtained by future measurements of oxygen, or by evolving models of second- generation low-mass stars with a non-canonical initial composition.

Research Organization:
University of North Carolina, Chapel Hill, NC (United States); Duke Univ., Durham, NC (United States). Triangle Universities Nuclear Laboratory
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP); Australian Research Council (ARC)
Grant/Contract Number:
FG02-97ER41041; FG02-97ER41033
OSTI ID:
1660982
Alternate ID(s):
OSTI ID: 1660983
Journal Information:
The Astrophysical Journal (Online), Vol. 818, Issue 1; ISSN 1538-4357
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 27 works
Citation information provided by
Web of Science

References (66)

Super-Agb-Agb Evolution and the Chemical Inventory in ngc 2419 journal December 2012
A Triple Main Sequence in the Globular Cluster NGC 2808 journal April 2007
The O-Na and Mg-Al anticorrelations in turn-off and early subgiants in globular clusters journal April 2001
The Globular Cluster ngc 2419: a Crucible for Theories of Gravity journal August 2011
Multiple populations in globular clusters: the possible contributions of stellar collisions: Multiple populations in globular clusters journal August 2010
Lithium abundances in globular cluster giants: NGC 1904, NGC 2808, and NGC 362★ journal April 2015
On the self-enrichment scenario of galactic globular clusters: constraints on the IMF journal October 2006
Rate Tables for the Weak Processes of sd-Shell Nuclei in Stellar Matter journal March 1994
News from the Galactic suburbia: the chemical composition of the remote globular cluster NGC 2419: Chemical composition of NGC 2419 journal October 2012
Updated stellar yields from asymptotic giant branch models journal April 2010
Evolution of massive AGB stars: III. the thermally pulsing super-AGB phase journal March 2010
Nuclear Physics of Stars book January 2015
Accreted versus in situ Milky Way globular clusters journal February 2010
The properties of Galactic globular cluster subsystems journal June 2005
Early disc accretion as the origin of abundance anomalies in globular clusters journal October 2013
Light nuclei in galactic globular clusters: constraints on the self-enrichment scenario from nucleosynthesis journal May 2007
NGC 2419: a large and extreme second generation in a currently undisturbed cluster: A large and extreme SG in NGC 2419 journal May 2011
The evolution of isotope ratios in the Milky Way Galaxy: The evolution of isotope ratios journal May 2011
The role of Thermohaline Mixing in Intermediate- and Low-Metallicity Globular Clusters journal March 2012
Super and massive AGB stars – III. Nucleosynthesis in metal-poor and very metal-poor stars – Z = 0.001 and 0.0001 journal April 2014
Lithium Abundances in Globular Cluster Giants: ngc 6218 (M12) and ngc 5904 (m5) journal July 2014
Heavy elements and chemical enrichment in globular clusters journal November 2004
Yields of AGB and SAGB models with chemistry of low- and high-metallicity globular clusters journal April 2013
A general abundance problem for all self-enrichment scenarios for the origin of multiple populations in globular clusters journal April 2015
Nucleosynthesis in classical novae journal October 2006
Stellar weak interaction rates for intermediate mass nuclei. III - Rate tables for the free nucleons and nuclei with A = 21 to A = 60 journal January 1982
The Multiplicity of the Subgiant Branch of ω Centauri: Evidence for Prolonged Star Formation journal July 2007
Stellar weak-interaction rates for sd-shell nuclei. I - Nuclear matrix element systematics with application to Al-26 and selected nuclei of importance to the supernova problem journal February 1980
The evolution of two stellar populations in globular clusters: I. The dynamical mixing timescale journal October 2008
Multiple populations in globular clusters: Lessons learned from the Milky Way globular clusters journal February 2012
Massive binaries as the source of abundance anomalies in globular clusters journal October 2009
The First Nova Explosions journal May 2007
Reaction rate of 24Mg(p,γ)25Al journal November 1999
An HST/WFC3 view of stellar populations on the horizontal branch of NGC 2419 journal November 2014
Abundance Variations within Globular Clusters journal September 2004
Polytropic Model fits to the Globular Cluster ngc 2419 in Modified Newtonian Dynamics journal November 2011
Starlib: a Next-Generation Reaction-Rate Library for Nuclear Astrophysics journal July 2013
The Bizarre Chemical Inventory of ngc 2419, an Extreme Outer halo Globular Cluster journal November 2012
On the Evolution of Stars That Form Electron-degenerate Cores Processed by Carbon Burning. II. Isotope Abundances and Thermal Pulses in a 10 M[SUB]sun[/SUB] Model with an ONe Core and Applications to Long-Period Variables, Classical Novae, and Accretion-induced Collapse journal March 1996
Supersoft X-rays reveal a classical nova in the M 31 globular cluster Bol 126 journal January 2013
Two Distinct red Giant Branch Populations in the Globular Cluster ngc 2419 as Tracers of a Merger Event in the Milky way journal November 2013
Lithium abundance in the globular cluster M4: from the turn-off to the red giant branch bump★: Lithium in M4 journal December 2010
NLTE determination of the aluminium abundance in a homogeneous sample of extremely metal-poor stars journal February 2008
Helium variation due to self–pollution among Globular Cluster stars: Consequences on the horizontal branch morphology journal October 2002
Signatures of intrinsic Li depletion and Li-Na anti-correlation in the metal-poor globular cluster NGC 6397 journal July 2009
THE EFFECTS OF THERMONUCLEAR REACTION RATE VARIATIONS ON 26 Al PRODUCTION IN MASSIVE STARS: A SENSITIVITY STUDY journal March 2011
On the Possibility of Nova Enrichment of Globular Clusters journal April 1996
Potassium: a new Actor on the Globular Cluster Chemical Evolution Stage. the case of ngc 2808 journal March 2015
The recurrent nova RS Oph: A possible scenario for type Ia supernovae journal October 2008
Lithium Abundances in red Giants of m4: Evidence for Asymptotic Giant Branch star Pollution in Globular Clusters? journal June 2010
Super- and massive AGB stars – IV. Final fates – initial-to-final mass relation journal November 2014
An Extended grid of nova Models. iii. very Luminous, red Novae journal November 2010
Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters journal January 2007
The age-metallicity dependence for white dwarf stars journal May 2015
Supermassive stars as a source of abundance anomalies of proton-capture elements in globular clusters journal October 2013
Statistical methods for thermonuclear reaction rates and nucleosynthesis simulations journal February 2015
Formation and dynamical evolution of multiple stellar generations in globular clusters journal December 2008
The Dawes Review 2: Nucleosynthesis and Stellar Yields of Low- and Intermediate-Mass Single Stars journal January 2014
Charged-particle thermonuclear reaction rates: I. Monte Carlo method and statistical distributions journal October 2010
Exploring Anticorrelations and Light Element Variations in Northern Globular Clusters Observed by the Apogee Survey journal April 2015
Recurrent novae as a consequence of the accretion of solar material onto a 1.38 solar mass white dwarf journal April 1985
The Gaia -ESO Survey: A globular cluster escapee in the Galactic halo journal March 2015
Na-O anticorrelation and HB: VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra journal July 2009
Novae from isolated white dwarfs as a source of helium for second-generation stars in globular clusters: Novae and second-generation stars journal May 2012
The cooling of oxygen—neon white dwarfs journal August 1997
An Extended Grid of Nova Models. II. The Parameter Space of Nova Outbursts journal April 2005

Cited By (20)

Super-AGB Stars and their Role as Electron Capture Supernova Progenitors journal January 2017
A Data-driven Model of Nucleosynthesis with Chemical Tagging in a Lower-dimensional Latent Space journal December 2019
Neutrino Spectra from Nuclear Weak Interactions in sd -Shell Nuclei under Astrophysical Conditions journal January 2018
The potassium abundance in the globular clusters NGC 104, NGC 6752 and NGC 6809 journal April 2017
On the discovery of K-enhanced and possibly Mg-depleted stars throughout the Milky Way journal July 2018
On Presolar Stardust Grains from CO Classical Novae journal March 2018
Magnesium isotopes: a tool to understand self-enrichment in globular clusters journal March 2018
Homogeneous analysis of globular clusters from the APOGEE survey with the BACCHUS code: I. The northern clusters⋆ journal February 2019
Revisiting nucleosynthesis in globular clusters: The case of NGC 2808 and the role of He and K journal December 2017
Multiple Stellar Populations and Their Evolution in Globular Clusters: A Nucleosynthesis Perspective journal January 2016
Trends in nuclear astrophysics journal May 2016
Abundances of Na, Mg, and K in the atmospheres of red giant branch stars of Galactic globular cluster 47 Tucanae journal July 2017
On the discovery of K-enhanced and possibly Mg-depleted stars throughout the Milky Way text January 2018
Light element discontinuities suggest an early termination of star formation in the globular cluster NGC 6402 (M14) journal March 2019
Multiple stellar populations and their evolution in globular clusters: A nucleosynthesis perspective text January 2016
Super-AGB Stars and their role as Electron Capture Supernova progenitors text January 2017
Magnesium isotopes: a tool to understand self-enrichment in Globular Clusters text January 2018
On the discovery of K-enhanced and possibly Mg-depleted stars throughout the Milky Way text January 2018
Light Element Discontinuities Suggest an Early Termination of Star Formation in the Globular Cluster NGC 6402 (M14) text January 2019
A data-driven model of nucleosynthesis with chemical tagging in a lower-dimensional latent space text January 2019

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