EROS 2 proper motion survey: Constraints on the halo white dwarfs
نویسندگان
چکیده
منابع مشابه
Eros 2 Proper Motion Survey for Halo White Dwarfs
Since 1996 EROS 2 has surveyed 440 at high Galactic latitude to search for high proper motion stars in the Solar neighbourhood. We present here the analysis of 250 for which we have three years of data. No object with halo-like kinematics has been detected. Using a detailed Monte-Carlo simulation of the observations, we calculate our detection efficiency for this kind of object and place constr...
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We analyse the kinematics of the entire spectroscopic sample of 99 recently discovered high proper-motion white dwarfs by Oppenheimer et al. using a maximum-likelihood analysis, and discuss the claim that the high-velocity white dwarfs are members of a halo population with a local density at least ten times greater than traditionally assumed. We argue that the observations, as reported, are con...
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We examine the chemical abundance constraints on a population of white dwarfs in the Halo of our Galaxy. We are motivated by microlensing experiments which have reported evidence for massive compact halo objects (Machos) in the Halo of our Galaxy, with an estimated mass of (0.1 − 1)M⊙; the only conventional dark astrophysical candidates for objects in this mass range are white dwarfs. However, ...
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We present the discovery and spectroscopic identification of two very high proper-motion ancient white dwarf stars, found in a systematic proper-motion survey. Their kinematics and apparent magnitude clearly indicate that they are halo members, while their optical spectra are almost identical to the recently identified cool halo white dwarf WD 0346+246. Canonical stellar halo models predict a w...
متن کاملDisk or Halo white dwarfs ? Kinematic analysis of high proper motion surveys
We present an alternative method for the kinematic analysis of high proper motion surveys and discuss its application to the survey of Oppenheimer et al. (2001) for the selection of reliable halo white dwarfs (WDs). The local WD space density we estimate is ρWD ≃ 1 ÷ 2 · 10 −5 M⊙pc −3 , which is about an order of magnitude smaller than the value derived in Oppenheimer et al. (2001), and is cons...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2002
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20020827