We study different models of dark matter distribution for the halo of our galaxy. In particular, we consider Eddington and King-Michie models, which include anisotropy in the velocity space, and we compute in a self- consistent way the amount of dark matter present in the halo. Assuming that the dark matter is in form of massive astrophysical compact halo objects (MACHOs), we find for each model the expected number of microlensing events and their average time duration for an experiment monitoring stars in the Large Magellanic Cloud (LMC). The main effect of including anisotropy is to reduce the microlensing rate and the mean MACHO mass by about 30%, as compared to the standard halo model, whereas the mean event duration increases noticeably. Consideration of different luminous models for the visible part of the galaxy also induces variations in the microlensing results by roughly the same amount as mentioned above.
Microlensing Rates from Selfconsistent Galactic Models
DE PAOLIS, Francesco;INGROSSO, Gabriele;
1996-01-01
Abstract
We study different models of dark matter distribution for the halo of our galaxy. In particular, we consider Eddington and King-Michie models, which include anisotropy in the velocity space, and we compute in a self- consistent way the amount of dark matter present in the halo. Assuming that the dark matter is in form of massive astrophysical compact halo objects (MACHOs), we find for each model the expected number of microlensing events and their average time duration for an experiment monitoring stars in the Large Magellanic Cloud (LMC). The main effect of including anisotropy is to reduce the microlensing rate and the mean MACHO mass by about 30%, as compared to the standard halo model, whereas the mean event duration increases noticeably. Consideration of different luminous models for the visible part of the galaxy also induces variations in the microlensing results by roughly the same amount as mentioned above.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.