Letter to the Editor

EROS 2 proper motion survey: Constraints on the halo white dwarfs^*

¹ CEA, DSM, DAPNIA, Centre d'Études de Saclay, 91191 Gif-sur-Yvette Cedex, France
² Collège de France, Physique Corpusculaire et Cosmologie, IN2P3 CNRS, 11 pl. M. Berthelot, 75231 Paris Cedex, France
³ NMSU, Department of Astronomy, Las Cruces, New Mexico 88003, USA
⁴ DASGAL, 77 avenue de l'Observatoire, 75014 Paris, France
⁵ Laboratoire de l'Accélérateur Linéaire, IN2P3 CNRS, Université Paris-Sud, 91405 Orsay Cedex, France
⁶ Astronomical Observatory, Copenhagen University, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
⁷ Institut d'Astrophysique de Paris, INSU CNRS, 98bis boulevard Arago, 75014 Paris, France
⁸ LESIA, Observatoire de Meudon, 92195 Meudon Cedex, France
⁹ ESO, Casilla 19001, Santiago 19, Chile
¹⁰ Ohio State University, Department of Astronomy, Columbus, OH 43210, USA
¹¹ University of Michigan, Department of Astronomy, Ann Arbor, MI 48109, USA
¹² LPNHE, IN2P3-CNRS-Universités Paris VI et VII, 4 place Jussieu, 75252 Paris Cedex 05, France
¹³ Observatoire de Marseille, 2 pl. Le Verrier, 13248 Marseille Cedex 04, France

Corresponding author: B.Goldman, bgoldman@nmsu.edu.

Received: 4 March 2002
Accepted: 3 June 2002

Abstract

We are conducting a proper motion survey in the ~V and I bands in order to determine the cool white dwarf contribution to the Galactic dark matter. Using the for which we possess three epochs, and applying selection criteria designed to isolate halo-type objects, we find no candidates in a effective volume for old, fast M_V=17 white dwarfs. We check the detection efficiency by cross-matching our catalogue with Luyten's NLTT catalogue. The halo white dwarf contribution cannot exceed 5% (95% C.L.) for objects with and . The same conclusion applies to a 14 Gyr halo composed of white dwarfs with hydrogen atmosphere, as modeled by Chabrier.