C18O Observations of the Dense Cloud Cores and Star Formation in Ophiuchus

2000 ◽  
Vol 528 (2) ◽  
pp. 817-840 ◽  
Author(s):  
Kengo Tachihara ◽  
Akira Mizuno ◽  
Yasuo Fukui
1998 ◽  
Vol 502 (1) ◽  
pp. 296-314 ◽  
Author(s):  
Toshikazu Onishi ◽  
Akira Mizuno ◽  
Akiko Kawamura ◽  
Hideo Ogawa ◽  
Yasuo Fukui

1998 ◽  
Vol 109 ◽  
pp. 47-60 ◽  
Author(s):  
Rene′ Plume ◽  
Edwin A. Bergin ◽  
Jonathan P. Williams ◽  
Philip C. Myers

1999 ◽  
Vol 51 (6) ◽  
pp. 895-910 ◽  
Author(s):  
Atsushi Hara ◽  
Kengo Tachihara ◽  
Akira Mizuno ◽  
Toshikazu Onishi ◽  
Akiko Kawamura ◽  
...  

2002 ◽  
Vol 385 (3) ◽  
pp. 909-920 ◽  
Author(s):  
K. Tachihara ◽  
T. Onishi ◽  
A. Mizuno ◽  
Y. Fukui

1997 ◽  
Vol 178 ◽  
pp. 19-30 ◽  
Author(s):  
F.H. Shu

We review current ideas and models in the problem of star formation from molecular cloud cores that are relatively isolated from the influences of other forming stars. We discuss the time scales, flow dynamics, and density and temperature structures applicable to each of the four stages of the entire process: (a) formation of a magnetized cloud core by ambipolar diffusion and evolution to a pivotal state of gravomagneto catastrophe; (b) self-similar collapse of the pivotal configuration and the formation of protostars, disks, and pseudo-disks; (c) onset of a magnetocentrifugally driven, lightly ionized wind from the interaction of an accretion disk and the magnetosphere of the central star, and the driving of bipolar molecular outflows; (d) evolution of pre-main-sequnce stars surrounded by dusty accretion disks. For each of these stages and processes, we consider the characteristics of the molecular diagnostics needed to investigate the crucial aspects of the observational problem.


2015 ◽  
Vol 11 (S315) ◽  
pp. 247-253
Author(s):  
Bruce G. Elmegreen

AbstractStar formation processes in strongly self-gravitating cloud cores should be similar at all redshifts, forming single or multiple stars with a range of masses determined by local magneto-hydrodynamics and gravity. The formation processes for these cores, however, as well as their structures, temperatures, Mach numbers, etc., and the boundedness and mass distribution functions of the resulting stars, should depend on environment, as should the characteristic mass, density, and column density at which cloud self-gravity dominates other forces. Because the environments for high and low redshift star formation differ significantly, we expect the resulting gas to stellar conversion details to differ also. At high redshift, the universe is denser and more gas-rich, so the active parts of galaxies are denser and more gas rich too, leading to slightly shorter gas consumption timescales, higher cloud pressures, and denser, more massive, bound stellar clusters at the high mass end. With shorter consumption times corresponding to higher relative cosmic accretion rates, and with the resulting higher star formation rates and their higher feedback powers, the ISM has greater turbulent speeds relative to the rotation speeds, thicker gas disks, and larger cloud and star complex sizes at the characteristic Jeans length. The result is a more chaotic appearance at high redshift, bridging the morphology gap between today's quiescent spirals and today's major-mergers, with neither spiral nor major-merger processes actually in play at that time. The result is also a thick disk at early times, and after in-plane accretion from relatively large clump torques, a classical bulge. Today's disks are thinner, and torque-driven accretion is slower outside of inner barred regions. This paper reviews the basic processes involved with star formation in order to illustrate its evolution over time and environment.


Sign in / Sign up

Export Citation Format

Share Document