Formation of Massive Molecular Cloud Cores by Cloud-Cloud Collision

Inoue, Tsuyoshi; Fukui, Y.

doi:10.1088/2041-8205/774/2/l31

Cited by 237 publications

(343 citation statements)

References 44 publications

(29 reference statements)

Supporting

Mentioning

307

Contrasting

Order By: Relevance

“…This find was further supported by colliding flow simulations of magnetized non-homogeneous gas by Inoue & Fukui (2013). They found the mass of the generated core depended on both this collision velocity and the strength of the initial magnetic field.…”

Section: Theoretical Models Of Cloud-cloud Collisionsmentioning

confidence: 59%

Do Cloud-Cloud Collisions Trigger High-Mass Star Formation? I. Small Cloud Collisions

Takahira

Tasker

Habe

2014

ApJ

177

230

View full text Add to dashboard Cite

We performed sub-parsec (∼0.06 pc) scale simulations of two idealized molecular clouds with different masses undergoing a collision. Gas clumps with densities greater than 10 −20 g cm −3 (0.3 × 10 4 cm −3 ) were identified as pre-stellar cores and tracked throughout the simulation. The colliding system showed a partial gas arc morphology with core formation in the oblique shock front at the collision interface. These characteristics support NANTEN observations of objects suspected to be colliding giant molecular clouds (GMCs). We investigated the effect of turbulence and collision speed on the resulting core population and compared the cumulative mass distribution to cores in observed GMCs. Our results suggest that a faster relative velocity increases the number of cores formed but that cores grow via accretion predominately while in the shock front, leading to a slower shock being more important for core growth. The core masses obey a power-law relation with index γ = −1.6, in good agreement with observations. This suggests that core production through collisions should follow a similar mass distribution as quiescent formation, albeit at a higher mass range. If cores can be supported against collapse during their growth, then the estimated ram pressure from gas infall is of the right order to counter the radiation pressure and form a star of 100 M .

show abstract

Section: Theoretical Models Of Cloud-cloud Collisionsmentioning

confidence: 59%

Do Cloud-Cloud Collisions Trigger High-Mass Star Formation? I. Small Cloud Collisions

Takahira

Tasker

Habe

2014

ApJ

177

230

View full text Add to dashboard Cite

show abstract

“…This produces highly gravitationally unstable molecular gas and may trigger very active star formation (e.g., Fukui et al 2014). Inoue & Fukui (2013) did magnetohydrodynamical simulations of a cloud-cloud collision and argue that it may lead to active formation of massive stars (see also Vaidya et al 2013). This mode of massive star formation is not, however, a prerequisite of our model.…”

Section: A Scenario Of Cloud Formation Driven By Expanding Bubblesmentioning

confidence: 99%

The formation and destruction of molecular clouds and galactic star formation

Inutsuka

Inoue

Iwasaki

et al. 2015

A&A

Self Cite

215

216

View full text Add to dashboard Cite

We describe an overall picture of galactic-scale star formation. Recent high-resolution magneto-hydrodynamical simulations of twofluid dynamics with cooling, heating, and thermal conduction have shown that the formation of molecular clouds requires multiple episodes of supersonic compression. This finding enables us to create a scenario in which molecular clouds form in interacting shells or bubbles on a galactic scale. First, we estimated the ensemble-averaged growth rate of molecular clouds on a timescale longer than a million years. Next, we performed radiation hydrodynamics simulations to evaluate the destruction rate of magnetized molecular clouds by the stellar far-ultraviolet radiation. We also investigated the resulting star formation efficiency within a cloud, which amounts to a low value (a few percent) if we adopt the power-law exponent ∼− 2.5 for the mass distribution of stars in the cloud. We finally describe the time evolution of the mass function of molecular clouds on a long timescale (>1 Myr) and discuss the steady state exponent of the power-law slope in various environments.

show abstract

“…Silk & Norman 2009;Inoue & Fukui 2013). Turbulence may be driven by the energy injection from young stars at high SF intensities (e.g.…”

Section: Exponents In the Generalizedmentioning

confidence: 99%

On the cosmic evolution of the specific star formation rate

Lehnert

Driel

Tiran

et al. 2015

A&A

View full text Add to dashboard Cite

The apparent correlation between the specific star formation rate (sSFR) and total stellar mass (M ) of galaxies is a fundamental relationship indicating how they formed their stellar populations. To attempt to understand this relation, we hypothesize that the relation and its evolution is regulated by the increase in the stellar and gas mass surface density in galaxies with redshift, which is itself governed by the angular momentum of the accreted gas, the amount of available gas, and by self-regulation of star formation. With our model, we can reproduce the specific SFR− M relations at z ∼ 1-2 by assuming gas fractions and gas mass surface densities similar to those observed for z = 1-2 galaxies. We further argue that it is the increasing angular momentum with cosmic time that causes a decrease in the surface density of accreted gas. The gas mass surface densities in galaxies are controlled by the centrifugal support (i.e., angular momentum), and the sSFR is predicted to increase as, sSFR(z) = (1 + z) 3 /t H0 , as observed (where t H0 is the Hubble time and no free parameters are necessary). In addition, the simple evolution for the star-formation intensity we propose is in agreement with observations of Milky Way-like galaxies selected through abundance matching. At z > ∼ 2, we argue that star formation is self-regulated by high pressures generated by the intense star formation itself. The star formation intensity must be high enough to either balance the hydrostatic pressure (a rather extreme assumption) or to generate high turbulent pressure in the molecular medium which maintains galaxies near the line of instability (i.e. Toomre Q ∼ 1). We provide simple prescriptions for understanding these self-regulation mechanisms based on solid relationships verified through extensive study. In all cases, the most important factor is the increase in stellar and gas mass surface density with redshift, which allows distant galaxies to maintain high levels of sSFR. Without a strong feedback from massive stars, such galaxies would likely reach very high sSFR levels, have high star formation efficiencies, and because strong feedback drives outflows, ultimately have an excess of stellar baryons.

show abstract

Formation of Massive Molecular Cloud Cores by Cloud-Cloud Collision

Cited by 237 publications

References 44 publications

Do Cloud-Cloud Collisions Trigger High-Mass Star Formation? I. Small Cloud Collisions

Do Cloud-Cloud Collisions Trigger High-Mass Star Formation? I. Small Cloud Collisions

The formation and destruction of molecular clouds and galactic star formation

On the cosmic evolution of the specific star formation rate

Contact Info

Product

Resources

About