the dynamics of stars, galaxies and clusters of galaxies offer strong circumstantial evidence for the existence of substantial amounts of matter that exerts a gravitational influence but which is not apparent at visible wavelengths. there have been recent claims for the direct detection of dark matter: two groups have detected stellar brightenings toward the large magellenic cloud that they attribute to micro-lensing of lmc stars by sub-stellar objects in the halo of the milky way; another group claims to have detected faint light in a halo around ngc5907 that follows the large scale needed to produce the flat rotation curve seen in this galaxy. but direct results are few and arguments continue about the nature of the dark matter. iso observations have a fundamental role to play in attacking this problem. perhaps the last refuge for baryonic dark matter is faint red stars, at or below the low mass cutoff of the main sequence. a cloud of stars or brown dwarfs with masses less than a few tenths of a solar mass could have escaped detection at visible wavelengths yet, if sufficient in number, could account for the missing halo matter. detection of the dark matter halo by iso would be a fundamental contribution to astrophysics. this proposal outlines an approach that, while at the limit of iso.s capabilities, will either detect a dark matter halo or set a useful upper limit to its content. finally, it is worth pointing out that these observations will result in a deep survey of about 0.07 sq.deg of high latitude sky at 4.5 um. the statistics of the star and galaxy counts at this flux level will be of interest by themselves.
Instrument
CAM03
Temporal Coverage
1996-05-19T10:05:15Z/1996-06-25T11:10:59Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, 1999, Search For Dark Matter Halos In Galaxies And Clusters. Part 1., 1.0, European Space Agency, https://doi.org/10.5270/esa-k6d7dt5
