The white dwarf cooling sequence of the globular cluster messier 4

  title={The white dwarf cooling sequence of the globular cluster messier 4},
  author={Brad M S Hansen and James Philip Brewer and Gregory G. Fahlman and Brad K. Gibson and Rodrigo A. Ibata and Marco Limongi and Robert Michael Rich and Harvey B. Richer and Michael M. Shara and Peter B. Stetson},
  journal={The Astrophysical Journal},
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V ~ 30 and I ~ 28. The white dwarf luminosity function rises sharply for I > 25.5, consistent with the behavior expected for a burst population. The white dwarfs of M4 extend to approximately 2.5 mag fainter than the peak of the local Galactic disk white dwarf luminosity function. This demonstrates a clear and significant age difference between the… 

Figures from this paper

Hubble Space Telescope Observations of the White Dwarf Cooling Sequence of M4
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
The White Dwarf Cooling Sequence of NGC 6397
We present the results of a deep Hubble Space Telescope (HST) exposure of the nearby globular cluster NGC 6397, focussing attention on the cluster's white dwarf cooling sequence. This sequence is
White Dwarf Sequences in Dense Star Clusters
We use the results of realistic N-body simulations to investigate the appearance of the white dwarf population in dense star clusters. We show that the presence of a substantial binary population in
The Lower Main Sequence and Mass Function of the Globular Cluster Messier 4
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope 123 orbit exposure in a single field of Messier 4, was obtained in two filters (F606W, F814W) over a 10 week period
A Distant White Dwarf Population in the 2QZ and Sloan Surveys
I present some properties of a distant population of white dwarf stars discovered in the Anglo-Australian Telescope 2dF QSO Redshift Survey (2QZ), in particular a new determination of the vertical
The Ages of the Thin Disk, Thick Disk, and the Halo from Nearby White Dwarfs
We present a detailed analysis of the white dwarf luminosity functions derived from the local 40 pc sample and the deep proper motion catalog of Munn et al (2014, 2017). Many of the previous studies
The white-dwarf cooling sequence of NGC 6791: a unique tool for stellar evolution
Context. NGC 6791 is a well-studied, metal-rich open cluster that is so close to us that it can be imaged down to luminosities fainter than that of the termination of its white-dwarf cooling
We explore the physics of crystallization in the deep interiors of white dwarf (WD) stars using the color-magnitude diagram and luminosity function constructed from proper-motion cleaned Hubble Space
Spectral types and masses of white dwarfs in globular clusters
White dwarfs in globular clusters offer additional possibilities to determine distances and ages of globular clusters, provided their spectral types and masses are known. We therefore started a
Revisiting the luminosity function of single halo white dwarfs
Context. 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


The Cool White Dwarf Luminosity Function and the Age of the Galactic Disk
We present new optical and infrared data for the cool white dwarfs in the proper motion sample of Liebert, Dahn, & Monet. Stellar properties—surface chemical composition, effective temperature,
A lower limit of 9.5 Gyr on the age of the Galactic disk from the oldest white dwarf stars
WHITE dwarf stars represent the final evolutionary state for most main-sequence stars. They cool slowly enough that even the oldest white dwarfs are still observable in sufficiently deep surveys and
High-Velocity White Dwarfs: Thick Disk, Not Dark Matter
We present an alternative interpretation of the nature of the extremely cool, high-velocity white dwarfs identified by Oppenheimer et al. in a high-latitude astrometric survey. We argue that the
Constraints on the age and evolution of the Galaxy from the white dwarf luminosity function
The white dwarf disk luminosity function is explored using observational results of Liebert et al. (1988, 1989) as a template for comparison, and the cooling curves of Wood (1990, 1991) as the input
White Dwarfs in Globular Clusters: Hubble Space Telescope Observations of M4*
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
The Luminosity Function of White Dwarfs
Trigonometric parallaxes, optical colors, and spectrophotometry are used to derive an empirical luminosity function for cool white dwarfs using the 1/V(max) method. To facilitate comparison with
Halo white dwarfs, thick disks and a sanity check
The recent discovery of a population of high proper-motion white dwarfs by Oppenheimer and coworkers has caused a lot of speculation as to the origin of these stars. I show that the age distribution
Direct Detection of Galactic Halo Dark Matter
A survey to find faint, cool white dwarfs with large space velocities, indicative of their membership in the galaxy's spherical halo component reveals a substantial, directly observed population of oldwhite dwarfs, too faint to be seen in previous surveys, and represents a direct detection of galactic halo dark matter.
The Chemical Evolution of Cool White Dwarfs and the Age of the Local Galactic Disk
Photometric and spectroscopic observations of 110 cool white dwarf stars are presented and analyzed with state-of-the-art model atmosphere calculations appropriate for cool white dwarfs with pure
The Relative Age of the Thin and Thick Galactic Disks
We determine the relative ages of the open cluster NGC 188 and selected Hipparcos field stars by isochrone fitting and compare them to the age of the thick-disk globular cluster 47 Tuc. The best-fit