Constraining white dwarf structure and neutrino physics in 47 Tucanae

Abstract

We present a robust statistical analysis of the white dwarf cooling sequence in 47 Tucanae. We combine HST UV and optical data in the core of the cluster, Modules for Experiments in Stellar Evolution (MESA) white dwarf cooling models, white dwarf atmosphere models, artificial star tests, and a Markov Chain Monte Carlo (MCMC) sampling method to fit white dwarf cooling models to our data directly. We use a technique known as the unbinned maximum likelihood to fit these models to our data without binning. We use these data to constrain neutrino production and the thickness of the hydrogen layer in these white dwarfs. The data prefer thicker hydrogen layers $(q_\mathrm{H}=3.2\e{-5})$ and we can strongly rule out thin layers $(q_{\mathrm{H}}=10^{-6})$. The neutrino rates currently in the models are consistent with the data. This analysis does not provide a constraint on the number of neutrino species.

arXiv comment12 pages, 15 figures

References in corpus (20)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Big-Bang Nucleosynthesis
• Correcting for the Effects of Interstellar Extinction
• The Dartmouth Stellar Evolution Database
• An Improved Spectroscopic Analysis of DA White Dwarfs from the Sloan Digital Sky Survey Data Release 4
• Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements
• New cooling sequences for old white dwarfs
• The White Dwarf Cooling Sequence of NGC6397
• The white dwarf cooling sequence in NGC 6791
• An Age Difference of 2 Gyr between a Metal-Rich and a Metal-Poor Globular Cluster
• The White Dwarf Distance to the Globular Cluster 47 Tucanae and its Age
• White dwarf evolutionary sequences for low-metallicity progenitors: The impact of third dredge-up
• The Physics of Crystallization from Globular Cluster White Dwarf Stars in NGC 6397
• Fe emission and ionized excess absorption in the luminous quasar 3C109 with XMM-Newton
• The Spectral Energy Distributions of White Dwarfs in 47 Tucanae: The Distance to the Cluster
• The neutrino emission due to plasmon decay and neutrino luminosity of white dwarfs
• Constraining Neutrino Cooling using the Hot White Dwarf Luminosity Function in the Globular Cluster 47 Tucanae
• Quantifying mass segregation and new core radii for 54 milky way globular clusters
• A Measurement of Diffusion in 47 Tucanae
• An Empirical Measure of the Rate of White Dwarf Cooling in 47 Tucanae

Cited by in corpus (11)

• A Multi-Mass Velocity Dispersion Model of 47 Tucanae Indicates No Evidence for an Intermediate Mass Black Hole
• The Gaia DR1 Mass-Radius Relation for White Dwarfs
• Axion Astrophysics
• Axions and the luminosity function of white dwarfs. The thin and thick disks, and the halo
• Polluting White Dwarfs with Perturbed Exo-Comets
• White dwarfs as Physics laboratories: lights and shadows
• Could compact stars in globular clusters constrain dark matter?
• Constraining Axions with ZTF J1901+1458
• The Onset of Convective Coupling and Freezing in the White Dwarfs of 47 Tucanae
• When Do Stars Go BOOM?
• The Cooling of Old White Dwarfs in 47 Tucanae