研究成果藝廊
Triggered Formation of Young Stars
Figure 1 shows DSS image of bright-rimmed cloud SFO21 whose ionizing star is located at 7 pc from the cloud. The arrow and diamond shows the direction of ionizing star and position of protostar, respectively. Figure 2 shows results of our numerical simulations. Panels from left to right indicate densities at the times t = 0, 6.3x10^4, and 9.6x10^4 year, respectively. Black line indicate ionization front. Initially, uniform cloud core is located at z = 2.5 pc. At t = 0, UV radiation turns on and illuminate from bottom side. Surface of the cloud is strongly compressed by ionization shock, and formation of next generation stars is expected due to its high density at head of the cloud.
Massive stars impact on surrounding environment through strong UV radiation, and are expected to trigger star formation due to compression of surrounding molecular gas. Bright-rimmed clouds (cometary shaped clouds found near massive star) are potential sites for such triggered star formation. (Motoyama, Umemoto, & Shang, 2007, A&A, 467, 657)