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Related papers: White Dwarf cooling Sequences, II: luminosity func…

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We present new observations of the white dwarf sequence of the old open cluster NGC 6791. The brighter peak previously observed in the white dwarf luminosity function (WDLF) is now better delineated, and the second, fainter peak that we…

Astrophysics · Physics 2009-11-13 L. R. Bedin , I. R. King , J. Anderson , G. Piotto , M. Salaris , S. Cassisi , A. Serenelli

Using WFPC2 on the Hubble Space Telescope, we have isolated a sample of 258 white dwarfs (WDs) in the Galactic globular cluster M4. Fields at three radial distances from the cluster center were observed and sizeable WD populations were…

The shape of the luminosity function of white dwarfs (WDLF) is sensitive to the characteristic cooling time and, therefore, it can be used to test the existence of additional sources or sinks of energy such as those predicted by alternative…

Solar and Stellar Astrophysics · Physics 2020-10-14 Jordi Isern

The evolution of white dwarfs is essentially a gravothermal process of cooling in which the basic ingredients for predicting their evolution are well identified, although not always well understood. There are two independent ways to test…

High Energy Astrophysical Phenomena · Physics 2022-02-07 Jordi Isern , Santiago Torres , Alberto Rebassa-Mansergas

Cooling white dwarfs (WDs) can yield accurate ages when theoretical cooling models fully account for the physics of the dense plasma of WD interiors. We use MESA to investigate cooling models for a set of massive and ultra-massive WDs…

Solar and Stellar Astrophysics · Physics 2020-10-21 Evan B. Bauer , Josiah Schwab , Lars Bildsten , Sihao Cheng

We examine the luminosity function of white dwarfs (WDs) in the local ``complete'' WD sample ($d<20$ pc) of Holberg et. al. 2008. We find that the fraction of bright and young WDs is anomalously high among the WDs detected in multiple…

Solar and Stellar Astrophysics · Physics 2014-03-03 Boaz Katz , Subo Dong , Doron Kushnir

The luminosity function of white dwarfs is a powerful tool for studies of the evolution and formation of the Milky Way. The (theoretical) white dwarf cooling sequence provides a useful indicator of the evolutionary time scales involved in…

Astrophysics · Physics 2009-10-31 Rene A. Mendez , Maria T. Ruiz

We present detailed evolutionary calculations for carbon - oxygen - and helium - core white dwarf (WD) models with masses ranging from M= 0.1 to M= 1.2 solar masses and for metallicities Z= 0.001 and Z= 0. The sequences cover a wide range…

Astrophysics · Physics 2016-08-30 O. G. Benvenuto , L. G. Althaus

Cooling ages of white dwarfs are routinely determined by mapping effective temperatures and masses to ages using evolutionary models. Typically, the reported uncertainties on cooling ages only consider the error propagation of the…

Solar and Stellar Astrophysics · Physics 2025-03-12 Praneet Pathak , Simon Blouin , Falk Herwig

We present full evolutionary calculations appropriate for the study of hydrogen-rich DA white dwarfs. This is done by evolving white dwarf progenitors from the zero age main sequence, through the core hydrogen burning phase, the helium…

We present new diagnostics of white dwarf (WD) cooling sequences and luminosity functions (LFs) in the near-infrared (NIR) bands that will exploit the sensitivity and resolution of future extremely large telescopes. The collision-induced…

Solar and Stellar Astrophysics · Physics 2015-06-12 G. Bono , M. Salaris , R. Gilmozzi

We present a new set of cooling models and isochrones for both H- and He-atmosphere white dwarfs, incorporating accurate boundary conditions from detailed model atmosphere calculations, and carbon-oxygen chemical abundance profiles based on…

Solar and Stellar Astrophysics · Physics 2015-05-18 M. Salaris , S. Cassisi , A. Pietrinferni , P. M. Kowalski , J. Isern

We make use of the high photometric precision of Kepler to search for periodic modulations among 14 normal (DA- and DB-type, likely non-magnetic) hot white dwarfs (WDs). In five, and possibly up to seven of the WDs, we detect periodic, ~2…

Solar and Stellar Astrophysics · Physics 2015-06-22 Dan Maoz , Tsevi Mazeh , Amy McQuillan

We make use of a previous well tested Galactic model, but describing the observational behavior of the various stellar components in terms of suitable assumptions on their evolutionary status. In this way we are able to predict the expected…

Astrophysics · Physics 2009-11-07 V. Castellani , M. Cignoni , S. Degl'Innocenti , S. Petroni , P. G. Prada Moroni

We develop the white dwarf luminosity function (LF) of the old open cluster NGC 188 in order to determine a lower limit to the age of the cluster by using the faint end of the cooling sequence. To produce an extensive sequence of the…

Astrophysics · Physics 2009-11-07 Gloria Andreuzzi , Harvey B. Richer , Marco Limongi , Michael Bolte

We study the evolution of white dwarf (WD) magnetic fields that originate from core-convective dynamos during the main-sequence. Using stellar evolution and WD cooling models combined with magnetic field diffusion calculations, we…

Solar and Stellar Astrophysics · Physics 2026-02-11 Matias Castro-Tapia , Maria Camisassa , Shu Zhang

The evolution of white dwarfs is essentially a cooling process that depends primarily on the energy stored in their degenerate cores and on the transparency of their envelopes. In this paper we compute accurate cooling sequences for…

Astrophysics · Physics 2009-10-31 M. Salaris , E. Garcia-Berro , M. Hernanz , J. Isern , D. Saumon

We present new white dwarf cooling models which incorporate an accurate outer boundary condition based on new opacity and detailed radiative transfer calculations. We find that helium atmosphere dwarfs cool considerably faster than has…

Astrophysics · Physics 2011-02-11 Brad M. S. Hansen

In this paper we demonstrate that the puzzling bright peak in the luminosity function of the white dwarf (WD) cooling sequence of NGC6791 can be naturally accounted for if ~34% of the observed WDs are WD+WD binary systems.

Astrophysics · Physics 2009-11-13 L. R. Bedin , M. Salaris , G. Piotto , S. Cassisi , A. P. Milone , J. Anderson , I. R. King

We present new cooling sequences, color-magnitude diagrams, and color-color diagrams for cool white dwarfs with pure hydrogen atmospheres down to an effective temperature $\te=1500$ K. We include a more detailed treatment of the physics of…

Astrophysics · Physics 2009-10-31 Gilles Chabrier , Pierre Brassard , Gilles Fontaine , Didier Saumon