Issue |
A&A
Volume 395, Number 1, November III 2002
|
|
---|---|---|
Page(s) | 31 - 35 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361:20021298 | |
Published online | 29 October 2002 |
Are there MACHOs in the Milky Way halo?
1
Department of Physics, Stockholm University, 106 91 Stockholm, Sweden () e-mail: amg@physto.se
2
Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
3
Laboratoire de Physique Mathématique et Théorique, Université de Montpellier II, 34095 Montpellier Cedex 5, France () e-mail: jedamzik@lpm.univ-montp2.fr
4
Max-Planck-Institut für Astrophysik, 85740 Garching, Germany
Corresponding author: A. M. Green, amg@physto.se
Received:
12
June
2002
Accepted:
5
September
2002
Microlensing searches aim to detect compact halo dark matter via its gravitational lensing effect on stars within the Large Magellanic Cloud. These searches have led to the claim that roughly one fifth of the galactic halo dark matter may be in the form of compact, solar-mass objects. We analyze this hypothesis by considering the goodness-of-fit of the best-fit halo dark matter solutions to the observational data. We show that the distribution of the durations of the observed microlensing events is significantly narrower than that expected to result from a standard halo lens population at 90 to 95% confidence, casting doubt on the lenses constituting halo dark matter. This conclusion may possibly be avoided if (i) the Milky Way halo is sufficiently nonstandard or (ii) a large fraction of the events are due to non-halo populations with event durations coincidentally close to those of the putative halo population or (iii) individual event durations have been seriously underestimated due to blending.
Key words: Galaxy: halo / cosmology: dark matter
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.