galaxies : elliptical and lenticular;
cD;
galaxies : kinematics and dynamics;
cosmology : dark matter;
D O I:
10.1051/0004-6361:20078569
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
We investigate how different models that have been proposed for solving the dark matter problem can fit the velocity dispersion observed around elliptical galaxies, on either a small scale (similar to 20 kpc) with stellar tracers, such as planetary nebulae, or large scale (similar to 200 kpc) with satellite galaxies as tracers. Predictions of Newtonian gravity, either containing pure baryonic matter, or embedded in massive cold dark matter (CDM) haloes, are compared with predictions of the modified gravity of MOND. The standard CDM model has problems on a small scale, and the Newtonian pure baryonic model has difficulties on a large scale, while a fit with MOND is possible on both scales.