SIMBAD references

We report here on a calculation of thermalization time-scale of the two temperature advection dominated accretion flow (ADAF) model. It is established that time required to equalize the electron and ion temperatures via electron-ion collisions in the ADAF with plausible physical parameters greatly exceeds the accretion time, which corroborates validity one of the crucial assumptions of the ADAF model, namely the existence of a hot two temperature plasma. This work is motivated by the recent success of the ADAF model [Nature 394 (1998) 651; MNRAS 304 (1999) 501] in explaining the emitted spectrum of Sgr A*, and it is complementary to the similar analysis of Mahadevan and Quataert [ApJ 490 (1997) 605].