Related papers: Formation of Massive Molecular Cloud Cores by Clou…
Massive stars influence their surroundings through radiation, winds, and supernova explosions far out of proportion to their small numbers. However, the physical processes that initiate and govern the birth of massive stars remain poorly…
We performed simulations of self-gravitating hydrodynamic turbulence to model the formation of filaments, clumps and cores in molecular clouds. We find that when the mass on the initial computational grid is comparable to the Jeans mass,…
All stars are born in molecular clouds, and most in giant molecular clouds (GMCs), which thus set the star formation activity of galaxies. We first review their observed properties, including measures of mass surface density, Sigma, and…
We have analyzed new CO($J$ = 1-0) data in the region of a reflection nebula NGC 2023 with a particular focus on the detailed kinematical properties of the molecular gas. The results show that there are two velocity components which…
We present the results of sulfur monoxide, SO line emission observations of G0.253+0.016 with the Atacama Large Millimeter/submillimeter Array (ALMA) at an angular resolution of 1.7 arcsec. The dense and massive molecular cloud of…
We report on a possible cloud-cloud collision in the DR 21 region, which we found through molecular observations with the Nobeyama 45-m telescope. We mapped an area of 8'x12' around the region with twenty molecular lines including the…
We demonstrate that the high pressure of the hot intracluster medium (ICM) can trigger the collapse of molecular clouds in a spiral galaxy, leading to a burst of star formation in the clouds. Our hydrodynamical simulations show that the…
We investigate the propagation of a shock wave into a warm neutral medium and cold neutral medium by one-dimensional hydrodynamic calculations with detailed treatment of thermal and chemical processes. Our main result shows that thermal…
We summarize the current status of the turbulent model of star formation in turbulent molecular clouds. In this model, clouds, clumps and cores form a hierarchy of nested density fluctuations caused by the turbulence, and either collapse or…
We construct models of molecular clouds that are considered as ensembles of transient cores. Each core is assumed to develop in the background gas of the cloud, grow to high density and decay into the background. The chemistry in each core…
Molecular clouds (MCs) are stellar nurseries, however, formation of stars within MCs depends on the ambient physical conditions. MCs, over a free-fall time are exposed to numerous dynamical phenomena, of which, the interaction with a thin,…
The winds and radiation from massive stars clear out large cavities in the interstellar medium. These bubbles, as they have been called, impact their surrounding molecular clouds and may influence the formation of stars therein. Here we…
The dense molecular cloud cores that form stars, like other self-gravitating objects, undergo bulk oscillations. Just at the point of gravitational instability, their fundamental oscillation mode has zero frequency. We study, using…
To investigate how molecular clouds react to different environmental conditions at a galactic scale, we present a catalogue of giant molecular clouds resolved down to masses of $\sim 10$~M$_{\odot}$ from a simulation of the entire disc of…
We analyzed the NANTEN2 13CO (J=2-1 and 1-0) datasets in NGC 2024. We found that the cloud consists of two velocity components, whereas the cloud shows mostly single-peaked CO profiles. The two components are physically connected to the HII…
Stars and more particularly massive stars, have a drastic impact on galaxy evolution. Yet the conditions in which they form and collapse are still not fully understood. In particular, the influence of the magnetic field on the collapse of…
(Abridged) We present numerical hydrodynamical simulations of the formation, evolution and gravitational collapse of isothermal molecular cloud cores. A compressive wave is set up in a constant sub-Jeans density distribution of radius r = 1…
The history of star formation in the strong gravitational potential of the Galactic center has been of much interest, recently. We propose that the sub-parsec-scale disk of massive stars orbiting the massive black hole at the Galactic…
We investigate star formation at very early evolutionary phases in five massive clouds in the inner 500 pc of the Galaxy, the Central Molecular Zone. Using interferometer observations of H$_2$O masers and ultra-compact H II regions, we find…
The collapse and fragmentation of initially filamentary, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate manner:…