English

Dark Matter -- Personal View

Astrophysics 2009-10-22 v1

Abstract

Traditional evidence for large amount of dark matter is based on dynamical consideration for systems with tdyntobs t_{dyn} \gg t_{obs} . Recent observational and theoretical developments in gravitational lensing offer a much more robust determination of the mass distribution in some galaxies and their clusters, with the precision comparable to that obtainable for double stars for which tdyn<tobs t_{dyn} < t_{obs} , and offer independent and direct evidence for the presence of dark matter. Gravitational microlensing and femtolensing offer a possibility to detect MACHOs with masses in excess of 1015 M \sim 10^{-15} ~ M_{\odot} . The recent detections of microlensing events by the EROS, MACHO and OGLE teams do not require any dark lenses as ordinary low mass stars are compatible with the observations. However, these searches will soon either detect genuine MACHOs, or they will place stringent upper limits on their number density.

Keywords

Cite

@article{arxiv.astro-ph/9412049,
  title  = {Dark Matter -- Personal View},
  author = {Bohdan Paczyński},
  journal= {arXiv preprint arXiv:astro-ph/9412049},
  year   = {2009}
}

Comments

8 pages, plain self-contained TEX, to appear in the Proceedings of the 5th Annual October Astrophysics Conference in Maryland: DARK MATTER, held on October 10-12, 1994 at College Park, Maryland