Probing Dark Matter
arXiv:astro-ph/9506059 · doi:10.1038/373191a0
Abstract
Recent novel observations have probed the baryonic fraction of the galactic dark matter that has eluded astronomers for decades. Late in 1993, the MACHO and EROS collaborations announced in this journal the detection of transient and achromatic brightenings of a handful of stars in the Large Magellanic Cloud that are best interpreted as gravitational microlensing by low-mass foreground objects (MACHOS). This tantalized astronomers, for it implied that the population of cool, compact objects these lenses represent could be the elusive dark matter of our galactic halo. A year later in 1994, Sackett et al. reported the discovery of a red halo in the galaxy NGC 5907 that seems to follow the inferred radial distribution of its dark matter. This suggested that dwarf stars could constitute its missing component. Since NGC 5907 is similar to the Milky Way in type and radius, some surmised that the solution of the galactic dark matter problem was an abundance of ordinary low-mass stars. Now Bahcall et al., using the Wide-Field Camera of the recently repaired Hubble Space Telescope, have dashed this hope.
3 pages, Plain TeX, no figures, published as a News and Views in Nature 373, 191 (1995)
References in corpus (4)
- Possible Gravitational Microlensing of a Star in the Large Magellanic Cloud
- Stars within the Large Magellanic Cloud as Potential Lenses for Observed Microlensing Events
- A Faint Luminous Halo that May Trace the Dark Matter around Spiral Galaxy NGC~5907
- M Dwarfs, Microlensing, and the Mass Budget of the Galaxy