| Issue |
EAS Publications Series
Volume 36, 2009
Dark Energy and Dark Matter: Observations, Experiments and Theories
|
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|---|---|---|
| Page(s) | 133 - 140 | |
| DOI | https://doi.org/10.1051/eas/0936018 | |
| Published online | 30 May 2009 | |
E. Pécontal, T. Buchert, Ph. Di Stefano and Y. Copin (eds)
EAS Publications Series, 36 (2009) 133-140
The mass distribution in Spiral galaxies
SISSA, via Beirut 2, Trieste, Italy;
Corresponding authors: salucci@sissa.it martins@sissa.it
In the past years a wealth of observations has unraveled the structural properties of the Dark and Luminous mass distribution in spirals. These have pointed out to an intriguing scenario not easily explained by present theories of galaxy formation. The investigation of individual and coadded objects has shown that the spiral rotation curves follow, from their centers out to their virial radii, a Universal profile (URC) that arises from the tuned combination of a stellar disk and of a dark halo. The importance of the latter component decreases with galaxy mass. Individual objects, on the other hand, have clearly revealed that the dark halos encompassing the luminous discs have a constant density core. This resulting observational scenario poses important challenges to presently favored theoretical ΛCDM Cosmology.
© EAS, EDP Sciences, 2009