The evolution of white dwarfs resulting from helium-enhanced, low-metallicity progenitor stars

Abstract

Some globular clusters host multiple stellar populations with different chemical abundance patterns. This is particularly true for $\omega$ Centauri, which shows clear evidence of a helium- enriched sub-population characterized by a helium abundance as high as $Y=0.4$. We present a whole and consistent set of evolutionary tracks from the ZAMS to the white dwarf stage appropriate for the study of the formation and evolution of white dwarfs resulting from the evolution of helium-rich progenitors. Different issues of the white dwarf evolution and their helium-rich progenitors have been explored. In particular, the final mass of the remnants, the role of overshooting during the thermally-pulsing phase, and the cooling of the resulting white dwarfs differ markedly from the evolutionary predictions of progenitor stars with standard initial helium abundance. Finally, the pulsational properties of the resulting white dwarfs are also explored. We find that, for the range of initial masses explored in this paper, the final mass of the helium-rich progenitors is markedly larger than the final mass expected from progenitors with the usual helium abundance. We also find that progenitors with initial mass smaller than $M_{\star }\simeq 0.65M_{\odot }$ evolve directly into helium-core white dwarfs in less than 14~Gyr, and that for larger progenitor masses the evolution of the resulting low-mass carbon-oxygen white dwarfs is dominated by residual nuclear burning. For helium-core white dwarfs, we find that they evolve markedly faster than their counterparts coming from standard progenitors. Also, in contrast with what occurs for white dwarfs resulting from progenitors with the standard helium abundance, the impact of residual burning on the cooling time of white dwarfs is not affected by the occurrence of overshooting during the thermally-pulsing phase of progenitor stars.

arXiv comment11 pages, 10 figures, 1 table. To be published in Astronomy and Astrophysics

References in corpus (56)

• Low Temperature Opacities
• Fast rotating massive stars and the origin of the abundance patterns in galactic globular clusters
• Updated Electron-Conduction Opacities: The Impact on Low-Mass Stellar Models
• Predictions for self-pollution in globular cluster stars
• Evolutionary and pulsational properties of white dwarf stars
• Post-Asymptotic Giant Branch Evolution of Low- and Intermediate-Mass Stars. Preliminary Results
• New models for the evolution of Post-Asymptotic Giant Branch stars and Central Stars of Planetary Nebulae
• Pulsating White Dwarf Stars and Precision Asteroseismology
• A helium spread among the main sequence stars in NGC 2808
• Helium variation due to self-pollution among Globular Cluster stars: consequences on the horizontal branch morphology
• New evolutionary sequences for extremely low mass white dwarfs: Homogeneous mass and age determinations, and asteroseismic prospects
• A New Version of Reimers' law of Mass Loss Based on a Physical Approach
• S-factor of 14N(p,gamma)15O at astrophysical energies
• New cooling sequences for old white dwarfs
• The formation and evolution of hydrogen-deficient post-AGB white dwarfs: the emerging chemical profile and the expectations for the PG1159-DB-DQ evolutionary connection
• A white dwarf cooling age of 8 Gyr for NGC 6791 from physical separation processes
• Luminosities and mass-loss rates of SMC and LMC AGB stars and Red Supergiants
• Semi-empirical white dwarf initial-final mass relationships: a thorough analysis of systematic uncertainties due to stellar evolution models
• The fraction of second generation stars in Globular Clusters from the analysis of the Horizontal Branch
• New Asymptotic Giant Branch models for a range of metallicities
• Modeling He-rich subdwarfs through the hot-flasher Scenario
• NGC 6441: another indication for a very high helium content in Globular Cluster stars
• A General Abundance Problem for All Self-Enrichment Scenarios for the Origin of Multiple Populations in Globular Clusters
• An Age Difference of 2 Gyr between a Metal-Rich and a Metal-Poor Globular Cluster
• Asteroseismic inferences on GW Vir variable stars in the frame of new PG 1159 evolutionary models
• Comparison of theoretical white dwarf cooling timescales
• New evolutionary models for massive ZZ Ceti stars: I. First results for their pulsational properties
• White dwarf evolutionary sequences for low-metallicity progenitors: The impact of third dredge-up
• The rate of cooling of the pulsating white dwarf star G117$-$B15A: a new asteroseismological inference of the axion mass
• Evolution and colours of helium-core white dwarf stars: the case of low metallicity progenitors
• The timescale of low-mass proto-helium white dwarf evolution
• Giants in the globular cluster omega Centauri: dust production, mass loss and distance
• New chemical profiles for the asteroseismology of ZZ Ceti stars
• Evolution of Thermally Pulsing Asymptotic Giant Branch Stars IV. Constraining Mass-Loss & Lifetimes of Low Mass, Low Metallicity AGB Stars
• The Physics of Crystallization from Globular Cluster White Dwarf Stars in NGC 6397
• Star Formation Histories of Globular Clusters with Multiple Populations. I. ω Cen, M22, and NGC 1851
• Helium and Multiple Populations in the Massive Globular Cluster NGC6266 (M62)
• The infrared eye of the Wide-Field Camera 3 on the Hubble Space Telescope reveals multiple main sequences of very low-mass stars in NGC 2808
• The intriguing stellar populations in the globular clusters NGC 6388 and NGC 6441
• New phase diagrams for dense carbon-oxygen mixtures and white dwarf evolution
• Thermohaline mixing and the photospheric composition of low-mass giant stars
• Outer boundary conditions for evolving cool white dwarfs
• The white dwarf luminosity function
• The mosaic multiple stellar populations in $\omega$ Centauri : the Horizontal Branch and the Main Sequence
• The mode trapping properties of full DA white dwarf evolutionary models
• Hot Horizontal Branch stars in omega Centauri: clues about their origin from the cluster Color Magnitude Diagram
• On the white dwarf cooling sequence of the globular cluster Omega Centauri
• A Double White-Dwarf Cooling Sequence in ω Centauri
• The White Dwarf Age of NGC 2477
• On the missing second generation AGB stars in NGC6752
• Evolution of long-lived globular cluster stars I. Grid of stellar models with helium enhancement at [Fe/H] = -1.75
• Why the globular cluster NGC 6752 contains no sodium-rich second-generation AGB star
• Evolution and nucleosynthesis of helium-rich asymptotic giant branch models
• Quiescent nuclear burning in low-metallicity white dwarfs
• On the white dwarf cooling sequence with extremely large telescopes
• NSV 11749, an elder sibling of the born again stars V605 Aql and V4334 Sgr?

Cited by in corpus (14)

• Pulsating white dwarfs: new insights
• Current challenges in the physics of white dwarf stars
• Explaining the multiple populations in globular clusters by multiple episodes of star formation and enrichment without gas expulsion from massive star feedback
• Pulsational instabilities driven by the $\epsilon$ mechanism in hot pre-horizontal branch stars I. The Hot-Flasher Scenario
• Pulsating low-mass white dwarfs in the frame of new evolutionary sequences: IV. The secular rate of period change
• Modeling the chemical enrichment history of the Bulge Fossil Fragment Terzan 5
• Forming Hot Subluminous Stars from Hierarchical Triples -- I. The Role of an Outer Tertiary on Formation Channels
• Post-common Envelope Evolution of Helium-core White Dwarfs
• Evolution of long-lived globular cluster stars IV. Initial helium content and white-dwarf properties
• Globular Cluster UVIT legacy Survey (GlobUleS) III. Omega Centauri in Far-Ultraviolet
• Multiple populations within globular clusters in Early-type galaxies Exploring their effect on stellar initial mass function estimates
• On the formation of hydrogen-deficient low-mass white dwarfs
• The $i$-processes nucleosynthesis during the formation of He-rich hot-subdwarf stars
• Asteroseismic study of KUV03442+0719 with parallax constraints