Related papers: Isochrones and Luminosity Functions for Old White …
The white dwarf luminosity function of a stellar cluster will have a sharp truncation at a luminosity which is determined by the time since formation of the first white dwarfs in that cluster. Calculation of the dependence of this limiting…
Given the importance of white dwarfs (WDs) in many fields of modern astrophysics, the precise knowledge of the actual degree of accuracy of the associated theoretical predictions is a primary task. In the first paper of a series dedicated…
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…
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…
Currently there are two main techniques for independently determining the ages of stellar populations: main sequence evolution theory (via cluster isochrones) and white dwarf cooling theory. Open clusters provide the ideal environment for…
Halo white dwarfs can provide important information about the properties and evolution of the galactic halo. In this paper we compute, assuming a standard IMF and updated models of white dwarf cooling, the expected luminosity function, both…
White dwarfs are the fossils left by the evolution of low-and intermediate-mass stars, and have very long evolutionary timescales. This allows us to use them to explore the properties of old populations, like the Galactic halo. We present a…
We report on the white dwarf cooling sequence of the old globular cluster NGC 6752, which is chemically complex and hosts a blue horizontal branch. This is one of the last globular cluster white dwarf (WD) cooling sequences accessible to…
White dwarfs are the final remnants of low- and intermediate-mass stars. Their evolution is essentially a cooling process that lasts for $\sim 10$ Gyr. Their observed properties provide information about the history of the Galaxy, its dark…
We present deep photometric observations of the open cluster NGC 2477 using HST/WFPC2. By identifying seven cluster white dwarf candidates, we present an analysis of the white dwarf age of this cluster, using both the traditional method of…
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…
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…
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular we study the influence of various systematic uncertainties, both observational and theoretical, on the determination of the cluster…
Thanks to their continuous cooling and relative simplicity, white dwarf stars are routinely used to measure the ages of stellar populations. The usefulness of white dwarfs as cosmochronometers depends on the availability of accurate cooling…
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 white dwarf luminosity function has proven to be an excellent tool to study some properties of the galactic disk such as its age and the past history of the local star formation rate. The existence of an observational luminosity…
We have cross-correlated the 2dF QSO Redshift Survey (2QZ) white dwarf catalog with the GALEX 2nd Data Release and the Sloan Digital Sky Survey (SDSS) data release 5 to obtain ultraviolet photometry (FUV, NUV) for approximately 700 objects…
We use 10 orbits of Advanced Camera for Surveys observations to reach the end of the white dwarf cooling sequence in the solar-metallicity open cluster NGC 2158. Our photometry and completeness tests show that the end falls at magnitude…
In the old, populous, and metal-rich open cluster NGC 6791 we have used deep HST/ACS images to track the white dwarf cooling sequence down to m_F606W~28.5. The white dwarf luminosity function shows a well defined peak at m_F606W~27.4, and a…
A deep imaging survey covering the entire $23\arcmin$ diameter of the old open cluster M67 to $V = 25$ has been carried out using the mosaic imager (UHCam) on the Canada-France-Hawaii Telescope. The cluster color-magnitude diagram (CMD) can…