scholarly journals Molecular Clouds and Star Formation Rate in Disk Galaxies

2016 ◽  
Vol 25 (3) ◽  
Author(s):  
E. O. Vasiliev ◽  
S. A. Khoperskov ◽  
A. V. Khoperskov
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Disk Galaxies

AbstractWe use

scholarly journals CHaMP: From Molecular Clouds to Massive Young Clusters

2015 ◽  
Vol 12 (S316) ◽  
pp. 123-124
Author(s):  
Peter J. Barnes
Keyword(s):  
Molecular Clouds ◽  
Star Formation Rate ◽  
Large Fraction ◽  
Cluster Formation ◽  
Formation Rate ◽  
Disk Galaxies ◽  
Pressure Threshold ◽  
Medium Mass ◽  
Uniform Sample ◽  
Massive Cluster

AbstractI review the major science outcomes to date of the Galactic Census of High- and Medium-mass Protostars (CHaMP), and also report the latest observational results on this unbiased, uniform sample of massive, cluster-forming molecular clumps, based on new mm-wave and IR data. These clouds represent the vast, subthermally-excited population of clumps predicted by Narayanan et al. (2008) to dominate the molecular mass of disk galaxies. Besides confirming their existence, we have presented evidence that these massive clumps probably spend a large fraction (90–95%) of their long lives (possibly up to 100 Myr) in a mostly quiescent, low star formation rate (SFR) state. This is likely ended when a density or internal pressure threshold is crossed, after which vigorous, massive cluster formation consumes the densest gas with a high SFR, dispersing the embedding envelope. New results presented in two other posters at this Symposium include (1) the first analysis of HCN emission from the dense gas (Schap et al.2015), and (2) the first deep photometry of clusters in this sample based on NIR AAT & CTIO data, and on MIR Warm Spitzer IRAC data (Dallilar et al.2015).

Evolution of the star-formation rate and extinction in disk galaxies at high z

2011 ◽  
Vol 55 (3) ◽  
pp. 193-201
Author(s):  
A. A. Kabanov ◽  
A. V. Tutukov ◽  
B. M. Shustov
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Disk Galaxies

scholarly journals Photoionizing feedback in spiral arm molecular clouds

2020 ◽  
Vol 495 (2) ◽  
pp. 1672-1691
Author(s):  
Thomas J R Bending ◽  
Clare L Dobbs ◽  
Matthew R Bate
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Total Mass ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Rapid Decrease ◽  
H Ii Regions ◽  
Noticeable Effect ◽  
Spiral Arm ◽  
Dense Features

ABSTRACT We present simulations of a 500 pc2 region, containing gas of mass 4 × 106 M⊙, extracted from an entire spiral galaxy simulation, scaled up in resolution, including photoionizing feedback from stars of mass >18 M⊙. Our region is evolved for 10 Myr and shows clustered star formation along the arm generating ≈ 5000 cluster sink particles ≈ 5 per cent of which contain at least one of the ≈ 4000 stars of mass >18 M⊙. Photoionization has a noticeable effect on the gas in the region, producing ionized cavities and leading to dense features at the edge of the H ii regions. Compared to the no-feedback case, photoionization produces a larger total mass of clouds and clumps, with around twice as many such objects, which are individually smaller and more broken up. After this we see a rapid decrease in the total mass in clouds and the number of clouds. Unlike studies of isolated clouds, our simulations follow the long-range effects of ionization, with some already dense gas, becoming compressed from multiple sides by neighbouring H ii regions. This causes star formation that is both accelerated and partially displaced throughout the spiral arm with up to 30 per cent of our cluster sink particle mass forming at distances >5 pc from sites of sink formation in the absence of feedback. At later times, the star formation rate decreases to below that of the no-feedback case.

scholarly journals Significance of bar quenching in the global quenching of star formation

2019 ◽  
Vol 628 ◽  
pp. A24 ◽  
Author(s):  
K. George ◽  
S. Subramanian ◽  
K. T. Paul
Keyword(s):  
Star Formation ◽  
Main Sequence ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Stellar Mass ◽  
Gas Content ◽  
Disk Galaxies ◽  
Local Universe ◽  
Star Forming ◽  
Barred Galaxies

The suppression of star formation in the inner kiloparsec regions of barred disk galaxies due to the action of bars is known as bar quenching. We investigate here the significance of bar quenching in the global quenching of star formation in the barred galaxies and their transformation to passive galaxies in the local Universe. We do this by measuring the offset of quenched barred galaxies from star-forming main sequence galaxies in the star formation rate-stellar mass plane and comparing it with the length of the bar, which is considered as a proxy of bar quenching. We constructed the star formation rate-stellar mass plane of 2885 local Universe face-on strong barred disk galaxies (z <  0.06) identified by Galaxy Zoo. The barred disk galaxies studied here fall on the star formation main sequence relation with a significant scatter for galaxies above stellar mass 1010.2M⊙. We found that 34.97% galaxies are within the intrinsic scatter (0.3 dex) of the main sequence relation, with a starburst population of 10.78% (above the 0.3 dex) and a quenched population of 54.25% (below the −0.3 dex) of the total barred disk galaxies in our sample. Significant neutral hydrogen (MHI > 109M⊙ with log MHI/M⋆ ∼ −1.0 to −0.5) is detected in the quenched barred galaxies with a similar gas content to that of the star-forming barred galaxies. We found that the offset of the quenched barred galaxies from the main sequence relation is not dependent on the length of the stellar bar. This implies that the bar quenching may not contribute significantly to the global quenching of star formation in barred galaxies. However, this observed result could also be due to other factors such as the dissolution of bars over time after star formation quenching, the effect of other quenching processes acting simultaneously, and/or the effects of environment.

scholarly journals Supernova Driving. IV. The Star-formation Rate of Molecular Clouds

2017 ◽  
Vol 840 (1) ◽  
pp. 48 ◽  
Author(s):  
Paolo Padoan ◽  
Troels Haugbølle ◽  
Åke Nordlund ◽  
Søren Frimann
Keyword(s):  
Star Formation ◽  
Molecular Clouds ◽  
Star Formation Rate ◽  
Formation Rate

scholarly journals The Mopra DQS survey of the G333 region

2006 ◽  
Vol 2 (S237) ◽  
pp. 404-404
Author(s):  
M. R. Cunningham ◽  
I. Bains ◽  
N. Lo ◽  
T. Wong ◽  
M. G. Burton ◽  
...  
Keyword(s):  
Star Formation ◽  
Magnetic Fields ◽  
Standard Model ◽  
Molecular Clouds ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Star Forming ◽  
Successful Model ◽  
The Standard Model ◽  
Forming Efficiency

Any successful model of star formation must be able to explain the low star forming efficiency of molecular clouds in our Galaxy. If the collapse of gas is regulated only by gravity, then the star formation rate should be orders of magnitude larger than the 1 M per year within our galaxy. The standard model invokes magnetic fields to slow down the rate of collapse, but does not explain star formation in cluster mode, or the lack of observed variations in the chemistry of molecular clouds if they are long-lived entities.

Sign in / Sign up

Export Citation Format

Share Document