... We try to determine the Galactic structure by comparing the observed and modeled velocities of OB-associations in the 3 kpc solar neighborhood. ... The velocities of gas particles averaged over large time intervals (8 bar rotation periods) are compared with the observed velocities of the OB-associations. ... We compare the model velocities of gas particles with the observed velocities of OB-associations in the neighborhood 3 kpc from the Sun. ... There is no secondary bar in this model. ...

SETI . ... 1.1 4 в 109 [1] Homo (4 - 5) в 106 [2]. ... Homo sapiens - , . ... Homo. 7. ­ (2 - 1, 5) в 106 [21]. ... Homo erecrus. 9. ­ 0, 4 в 106 [23]. Homo - - Homo erectus. ... 1981 [30]. . ... R (T ) (Star Formation Rate, SFR). ... B (M , ) LC ( ), , , 39 Number of civilizations Self-consistent origin of life 3500 3000 2500 2000 1500 1000 500 00 2 4 6 8 10 12 14 Post transition civilizations Uniform single-planets origin of life 16 18 20 22 Time, Gyr . ... Lexington Bo oks, 2003. ... 2001. ...