Article
Astronomy & Astrophysics
Sarah M. R. Jeffreson, Benjamin W. Keller, Andrew J. Winter, Melanie Chevance, J. M. Diederik Kruijssen, Mark R. Krumholz, Yusuke Fujimoto
Summary: The study reveals that molecular clouds merge at a rate proportional to the time between their centroids, but their physical properties are largely unaffected by these interactions. Below the gas-disc scale height, cloud lifetime scales with cloud size following a power-law relation, while above the disc scale height, this scaling relation flattens to a constant value.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Sarah M. R. Jeffreson, Mark R. Krumholz, Yusuke Fujimoto, Lucia Armillotta, Benjamin W. Keller, Melanie Chevance, J. M. Diederik Kruijssen
Summary: A novel physically motivated sub-grid model for Hii region feedback is presented, which shows that the injection of momentum has a significant impact on the ratio of cold and molecular gas, as well as decreasing the mass-loading of galactic outflows. The simulations indicate that the characteristic lifetime of the least-massive molecular clouds is reduced, while the lifetimes of intermediate-mass clouds are elongated.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Sajay Sunny Mathew, Christoph Federrath
Summary: The study demonstrates that various factors in star cluster formation, including protostellar outflows, affect the star formation rate, mass distribution, and initial mass function. The turbulence-based model and observational IMF agree well in the high-mass and low-mass regime, but do not predict any brown dwarfs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Vianey Camacho, Enrique Vazquez-Semadeni, Aina Palau, Manuel Zamora-Aviles
Summary: We conducted a numerical study on the balance of gravitational, kinetic, and magnetic energies in hub-filament structures within a giant molecular cloud. The study examined the scaling relationships between the virial parameter, Larson ratio, and mass and column density of the structures. We also compared our numerical results with an observational sample of massive clumps and found similar trends. The main controlling parameter of the energy budget in the structures is gravitational energy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Eric P. Andersson, Florent Renaud, Oscar Agertz
Summary: The study suggests that runaway stars might contribute to the phenomenon of star formation in the outskirts of spiral galaxies, enabling the appearance of star formation in regions with extremely low gas surface densities.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jaeyeon Kim, Melanie Chevance, J. M. Diederik Kruijssen, Andreas Schruba, Karin Sandstrom, Ashley T. Barnes, Frank Bigiel, Guillermo A. Blanc, Yixian Cao, Daniel A. Dale, Christopher M. Faesi, Simon C. O. Glover, Kathryn Grasha, Brent Groves, Cinthya Herrera, Ralf S. Klessen, Kathryn Kreckel, Janice C. Lee, Adam K. Leroy, Jerome Pety, Miguel Querejeta, Eva Schinnerer, Jiayi Sun, Antonio Usero, Jacob L. Ward, Thomas G. Williams
Summary: Feedback from massive stars is crucial in molecular cloud evolution. The embedded phase of massive star formation lasts 2-7 million years, with the region heavily obscured in the first half and partially exposed in the second half. After the cloud disperses, ongoing star formation is no longer traced by 24 emission, but can be detected through ambient CO-dark gas emissions for 2-9 million years. Future JWST observations will enable routine measurements across nearby galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Sajay Sunny Mathew, Christoph Federrath, Amit Seta
Summary: Turbulence is crucial for star formation, but its role in the initial mass function (IMF) is not fully understood. Magnetohydrodynamical simulations reveal that compressive turbulence driving produces a higher fraction of low-mass stars compared to solenoidal driving. The simulations capture the important features of the observed IMF form.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Maya A. Petkova, J. M. Diederik Kruijssen, Jonathan D. Henshaw, Steven N. Longmore, Simon C. O. Glover, Mattia C. Sormani, Lucia Armillotta, Ashley T. Barnes, Ralf S. Klessen, Francisco Nogueras-Lara, Robin G. Tress, Jairo Armijos-Abendano, Laura Colzi, Christoph Federrath, Pablo Garcia, Adam Ginsburg, Christian Henkel, Sergio Martin, Denise Riquelme, Victor M. Rivilla
Summary: In this study, the authors investigated the influence of the Galactic gravitational potential on the turbulence in the Central Molecular Zone (CMZ) clouds of our Galaxy. They found that the Galactic shear, in combination with the cloud's gravitational collapse, significantly affects the kinematic properties and turbulence of the CMZ clouds, leading to a suppression in the star formation rate (SFR).
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Maya A. Petkova, J. M. Diederik Kruijssen, A. Louise Kluge, Simon C. O. Glover, Daniel L. Walker, Steven N. Longmore, Jonathan D. Henshaw, Stefan Reissl, James E. Dale
Summary: By comparing the ALMA observations and simulations of the Brick cloud, this study reveals differences in the density probability distribution function and moments of inertia, which are attributed to the absence of magnetic fields in the simulations. This demonstrates that the Galactic potential can account for many cloud properties, but additional physical processes are necessary to fully explain the gas structure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jacob L. Ward, J. M. Diederik Kruijssen, Melanie Chevance, Jaeyeon Kim, Steven N. Longmore
Summary: This paper aims to study the lifecycle of molecular clouds in the Large Magellanic Cloud (LMC) and determines their lifetime to be around 11.8 million years. The study finds that molecular clouds in the LMC are decoupled from galactic dynamics and have short lifetimes regulated by internal processes, while atomic clouds are correlated with galactic dynamical timescales.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jonathan C. Bird, Sarah R. Loebman, David H. Weinberg, Alyson M. Brooks, Thomas R. Quinn, Charlotte R. Christensen
Summary: Kinematic studies of disc galaxies, using individual stars in the Milky Way or statistical studies of global disc kinematics over time, provide insights into how discs form and evolve. The key to success in understanding this process lies in the simulation's dynamically cold multiphase ISM, allowing young stars to form with low velocity dispersion. The evolution of disc galaxies is explained by a model where the decrease in velocity dispersion is due to a decreasing gas fraction over time, resulting in a quasi-stable equilibrium.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. A. Kuhn, R. A. Benjamin, C. Zucker, A. Krone-Martins, R. S. de Souza, A. Castro-Ginard, E. E. O. Ishida, M. S. Povich, L. A. Hillenbrand
Summary: In this study, the researchers mapped the distribution of 25 star-forming regions in a segment of the Milky Way with a high degree of coherence and identified a linear structure with a high pitch angle of 56 degrees. The structure showed consistent motions in the Galactic rotation direction, with slight inward drifts and in the negative Z direction.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. S. N. Kumar, D. Arzoumanian, A. Men'shchikov, P. Palmeirim, M. Matsumura, S. Inutsuka
Summary: This study examines the detailed structure of the Mon R2 star-forming region, focusing on the role of hub-filament systems in massive star formation. The researchers find that lower density filaments converge to form higher density filaments within the hub. The structure of the hub is not a single massive clump as previously believed, but rather a network of short, high-density filaments. The analysis shows that the total mass in the region is distributed between filaments, an extended cloud, and sources. The orientation and mass per unit length of the filaments also vary with distance from the hub center.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Henry B. Lane, Michael Y. Grudic, David Guszejnov, Stella S. R. Offner, Claude-Andre Faucher-Giguere, Anna L. Rosen
Summary: Simulating isolated giant molecular clouds is important for studying star formation dynamics, but the initial conditions of turbulence are uncertain. Researchers have developed a new simulation setup that combines advantages of previous methods and found that external driving can significantly suppress star formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Glen H. Hunter, Paul C. Clark, Simon C. O. Glover, Ralf S. Klessen
Summary: In this study, the impact of collision speed, magnetic field inclination, and resolution on the star formation rate (SFR) in cloud-cloud collisions is investigated. A factor of 2-3 increase in the SFR is found compared to no collision simulations, with high collisional velocities, parallel magnetic field and collision axis orientation, and lower resolution leading to earlier star formation. The alignment of velocity and magnetic field is consistent in low-density environments but becomes more perpendicular as density increases, indicating the compression of the magnetic field by collapsing gas.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)