PPT-Formation and Dynamical Evolution of Star Clusters

WenPing Chen National Central University Census of Galactic open clusters Dynamical evolution of a star cluster Star clusters as targets and as tools Outstanding issues 2017 April 28 PMO . What force makes stars? . Gravity!. Out of what? Interstellar gas and dust. But this stuff is VERY low density… a dense area may have ~100 atoms / cm. 3. . Compare that the air you’re breathing… ~10. With a wide-field multi-IFU spectrograph. Cluster studies. Clusters provide large samples of galaxies in a moderate field. Unique perspective on the interaction of galaxies with their environment. As they operate much as a closed box, they are useful as tracers of galaxy evolution and of cosmology. . CDM Cosmology. Oleg . Gnedin. (University of Michigan. ). What we knew before HST: globular clusters are old, dense, compact – a distinct type of stellar spheroids. Kormendy. (1985). Over 20 years the Hubble Space Telescope has revealed young massive star clusters in interacting and gas-rich galaxies.. Drs. Carol Christian, Antonella Nota, and Brad Whitmore. May 7, 2015. Stars /Star Clusters. Carol Christian. Stars form from gas and dust clouds. The clouds collapse due to gravity. Also the clouds can collide / compress. Christopher W. Ashcraft M.S., M.Ed.. Big Bang vs. Creation. Origin of Stars. Solar System: Evidence of Design. Age of the Cosmos. Are we being told all the evidence or just selected information to support a particular idea?. D. Calzetti (Univ. of Massachusetts). a. nd the LEGUS . Team. https://. legus.stsci.edu. /. HUBBLE2020: Hubble’s 25. th. Anniversary Symposium. STScI. , Baltimore, April 20-24, 2015. NGC3344. NGC1566. Prof. Gerhardt R Meurer. Galaxy evolution in a nutshell. Galaxy Evolution. 2. Time machines. The farther we peer. The farther back in time we see. Reveal cosmic history. Hubble: to < 1 . Gyr. after big bang. Oleg . Gnedin. (University of Michigan. ). g. raduate student . Hui. Li. Star clusters are dominant components of active star formation:. they connect small-scale SF (local) and global processes in galaxies. Key variable is . mass. of star. directly measured only for binary stars, but it determines position on main sequence. Cluster ages. Main-sequence luminosity increases . much. faster than mass. therefore massive stars use up their fuel much faster. Evolution off the Main Sequence. Main Sequence Lifetimes. Most massive (O and B stars): millions of years. Stars like the Sun (G stars): billions of years. Low mass stars (K and M stars): a trillion years! . Ann Marie Cody. NPP fellow at NASA Ames. November 2, 2015. Acknowledgments. Ames collaborators. : Steve Howell, Tom Barclay, Fergal . Mullally. , Susan Thompson, . Geert. . Barentsen. , Jason Rowe, student interns: Bryan Mann, . and Future of Binary Stars. Max Moe (University of Arizona). Einstein Fellows Symposium . –. Oct. 12, 2017. Formation of Very Close Binaries. ~80% of solar-type binaries . with P. inner. . < 7 days have tertiary companions. Laura . Magrini. INAF- . Osservatorio. . Astrofisico. di . Arcetri. In Our Galaxy. Open clusters (disc population): . Many (~2200 known clusters). . even more new candidates in the inner disc from infrared surveys . Jeff Mangum. NRAO. 2. Extragalactic Star Formation. 3. Multi-transition analysis of molecular excitation within high spatial. . density (n(H2) > 10^5 cm^-3) and high kinetic temperature (. Tk. > 100 K) environments.