extended dark halos are well established around isolated unperturbed spiral galaxies, and may also exist around ellipticals. there is a close coincidence between the total mass in spiral halos and the total baryonic mass in the universe, deduced from light element nucleosynthesis. thus, dark halos may be baryonic. the only form for this dark baryonic matter which has not been excluded is brown dwarfs of a few jupiter masses. iso observations of carefully selected galaxies will either see this mass, or prove dark matter to be non-baryonic. the sample galaxies must be edge-on, have rotation curves, be isolated, have no bulge or strong thick disc, and preferably be of high enough redshift so their angular size is well matched to the isocam field of view. one may then fit dynamically-allowed surface density distributions to the surface brightness data for several galaxies, to search for consistent results. we have isolated such a sample, and will use isocam to detect or disprove the existence of brown dwarfs as the explanation of dark matter halos in spiral galaxies.
Instrument
CAM01
Temporal Coverage
1996-06-16T06:21:42Z/1998-03-30T20:32:20Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds 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, GILMORE et al., 1999, 'BROWN DWARF HALOS OF LOW REDSHIFT SPIRAL GALAXIES', 1.0, European Space Agency, https://doi.org/10.5270/esa-bg9inqr
