Article
Astronomy & Astrophysics
Michael D. Smith, Carl Richards
Summary: The Mach number is a crucial parameter in determining the driving properties and impact on the environment of a supersonic jet. Through numerical simulations, we investigate the effects of different Mach numbers and jet overpressures on the flow pattern and shock locations. We also analyze potential observational diagnostics and the energy transferred into the environment.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
L. Bonne, N. Peretto, A. Duarte-Cabral, A. Schmiedeke, N. Schneider, S. Bontemps, A. Whitworth
Summary: By studying the newly discovered star-forming cloud G345.88-1.10, strong constraints on the evolution of massive protostellar objects can be obtained. The study found that the infrared-quiet fragments in the cloud are spatially associated with a powerful molecular outflow, and the presence of radio continuum and ionizing radiation does not seem to affect the evolution of the cavities.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
T. Nony, R. Galvan-Madrid, F. Motte, Y. Pouteau, N. Cunningham, F. Louvet, A. M. Stutz, B. Lefloch, S. Bontemps, N. Brouillet, A. Ginsburg, I. Joncour, F. Herpin, P. Sanhueza, T. Csengeri, A. P. M. Towner, M. Bonfand, M. Fernandez-Lopez, T. Baug, L. Bronfman, G. Busquet, J. Di Francesco, A. Gusdorf, X. Lu, F. Olguin, M. Valeille-Manet, A. P. Whitworth
Summary: This study compares populations of protostellar and prestellar cores in the W43 molecular complex observed by the ALMA-IMF Large Program. The results show that the fraction of protostellar cores is about 35% in both regions, but varies significantly with mass. The high-mass cores are found to be more likely to be protostellar, and protostellar cores tend to be more massive and smaller in size than prestellar cores. The difference in slopes of the prestellar and protostellar core mass functions suggests that high-mass cores grow more in mass than low-mass cores.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
S. Anathpindika, J. Di Francesco
Summary: This study explores the formation of prestellar cores and reveals that cores formed under different pressures exhibit distinct shapes, as well as the relationship between velocity gradient variations and filament evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
T. Baug, Ke Wang, Tie Liu, Yue-Fang Wu, Di Li, Qizhou Zhang, Mengyao Tang, Paul F. Goldsmith, Hong-Li Liu, Anandmayee Tej, Leonardo Bronfman, Kee-Tae Kim, Shanghuo Li, Chang Won Lee, Ken'ichi Tatematsu, Tomoya Hirota, L. Viktor Toth
Summary: Through a statistical study of outflows in 11 massive protoclusters, this research finds that the outflows mainly consist of low-mass outflows with at least one high-mass outflow in each target, and suggests a possible decrease in outflow rate over time. Additionally, the study reveals that massive cores may have longer accretion histories.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
David J. Whitworth, Rowan J. Smith, Ralf S. Klessen, Mordecai-Mark Mac Low, Simon C. O. Glover, Robin Tress, Ruediger Pakmor, Juan D. Soler
Summary: Many studies have shown that magnetic fields can suppress star formation in molecular clouds and Milky Way like galaxies. However, most of these studies have focused on fully developed fields at saturation level, and there is little understanding of how weak initial primordial fields affect star formation in low metallicity environments. In this paper, the impact of a weak initial field on low metallicity dwarf galaxies is investigated. High-resolution AREPO simulations are performed, and the results show that the magnetic field has little impact on the global star formation rate (SFR), contrary to some previous studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Rong Liu, Tie Liu, Gang Chen, Hong-Li Liu, Ke Wang, Jin-Zeng Li, Chang Won Lee, Xunchuan Liu, Mika Juvela, Guido Garay, Lokesh Dewangan, Archana Soam, Leonardo Bronfman, Jinhua He, Chakali Eswaraiah, Si-Ju Zhang, Yong Zhang, Feng-Wei Xu, L. Viktor Toth, Zhi-Qiang Shen, Shanghuo Li, Yue-Fang Wu, Sheng-Li Qin, Zhiyuan Ren, Guoyin Zhang, Anandmayee Tej, Paul F. Goldsmith, Tapas Baug, Qiuyi Luo, Jianwen Zhou, Chang Zhang
Summary: In this study, we observed SiO emission in 146 massive star-forming regions and found that SiO clumps are associated with outflow activities and HII regions. The SiO line luminosity is positively correlated with the bolometric luminosity, suggesting a connection between stronger shock activities and more luminous protoclusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Avison, G. A. Fuller, N. Peretto, A. Duarte-Cabral, A. L. Rosen, A. Traficante, J. E. Pineda, R. Guesten, N. Cunningham
Summary: The infrared dark cloud SDC335.579-0.292 is a massive star-forming cloud with high-mass protostellar objects at early evolution stages. Molecular outflow observations reveal that the protostars in SDC335 are in the early stages of evolution (Class 0) with a total accretion rate of 1.4 x 10^-3 solar masses per year.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Patrick Hennebelle
Summary: This paper investigates the role of turbulence in the formation of astrophysical structures through 3D and 1D simulations, providing insights into turbulence behavior and dissipation parameters during collapse. The results show that turbulence amplification or generation depends on the cloud's thermal support, with implications for understanding gravitational collapse dynamics.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Shivan Khullar, Christoph Federrath, Mark R. Krumholz, Christopher D. Matzner
Summary: This study uses numerical experiments to investigate the density probability distribution function in supersonic, isothermal, self-gravitating turbulence, showing a universal form consisting of a lognormal at low density and power-law tails at higher density. It introduces a new diagnostic, the dimensionless star formation efficiency versus density curve, and demonstrates the influence of both the Mach number and the virial parameter on the PDF shape.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yue Hu, Christoph Federrath, Siyao Xu, Sajay Sunny Mathew
Summary: The interaction between turbulence, magnetic fields, self-gravity, and stellar feedback is crucial for understanding star formation. This study focuses on the effects of self-gravity and outflow feedback on the turbulent velocity within molecular clouds. The results show that outflow feedback can change the scaling of velocity fluctuations and amplify turbulence. Self-gravity and protostellar outflows increase velocity fluctuations and enhance fragmentation. The study also finds that self-gravity has a more significant effect on smaller dense clumps, while outflow feedback drives a higher fraction of solenoidal modes relative to compressive modes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rogelio Orozco-Duarte, Guillermo Garcia-Segura, Aida Wofford, Jesus A. Toala
Summary: This study addresses the problem of the observed soft X-ray emission in superbubbles that cannot be explained by models assuming a constant density medium and central supernova events. By generating models that trace the history of supernovae in the superbubble and produce off-centre supernovae, the missing soft X-ray emission can be accounted for. Testing the models against observations of DEM L50 in the Large Magellanic Cloud, it is found that the configuration where DEM L50 forms at the edge of a filament reproduces the observed soft X-ray luminosity and other properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Lars Mattsson, Robert Hedvall
Summary: The dynamics of interstellar dust particles in forced compressible transonic turbulence simulations were investigated, showing that self-gravity can significantly accelerate large grains and increase clustering for intermediate-sized grains. This suggests that self-gravity effects can play a crucial role in dust aggregation/coagulation even in non-Jeans-unstable turbulent systems.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Soumen Deb, Roland Kothes, Erik Rosolowsky
Summary: This paper analyzes 13 outflows in the Cygnus X star-forming region using new observations and develops a method to measure their properties using existing line data. The results show consistency in mechanical properties and associated protostars. The developed method shows agreement in properties within a factor of 2.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Mauricio Tapia, Paolo Persi
Summary: The well-studied massive star-forming region IRAS 23139+5939 is found to be a multiple massive young stellar object with Class I spectral energy distribution. It is associated with methanol and water masers, compact H ii regions, and H-2 emission knots. There is also a young embedded stellar cluster with evidence of protoplanetary discs. Gaia Data Release 3 and parallaxes indicate a common distance of 3.34 kpc to IRAS 23139+5939 and a nearby H alpha-emission star.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Anton Peshkov, Sonia McGaffigan, Alice C. Quillen
Summary: There is a recent surge of interest in the behavior of active particles that can align their direction of movement and synchronize their oscillations. Researchers conducted an experimental investigation on the collective motion of the nematode Turbatrix aceti and discovered their ability to synchronize body oscillations, resulting in strong fluid flows. The location and strength of this collective state can be controlled by adjusting the shape of the confining structure, offering potential for producing controllable work.
Review
Astronomy & Astrophysics
Peter M. Miklavcic, John Siu, Esteban Wright, Alex Debrecht, Hesam Askari, Alice C. Quillen, Adam Frank
Summary: In this paper, the authors explore the potential of using near-earth asteroids as habitats for human settlement. They find that it is possible to maintain the integrity of a rotating asteroid by using high-strength materials as containers. This research expands the range of possible asteroid habitats and suggests the feasibility of constructing habitats from smaller bodies.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2022)
Article
Astronomy & Astrophysics
Esteban Wright, Alice C. Quillen, Paul Sanchez, Stephen R. Schwartz, Miki Nakajima, Hesam Askari, Peter Miklavcic
Summary: We conducted experiments to compare low velocity impacts on granular media with different mean grain sizes but similar density, porosity, and friction coefficient. Our results show that the coefficients of restitution, which represent the ratio of pre-to post-impact velocity components, are sensitive to mean grain size. The lift coefficient, in particular, is the most strongly affected by grain size, decreasing by a factor of 3 between the coarsest and finest media. The deflection angles caused by the impact are largest in coarser media and vary approximately with grain size to the power of 3/2. These findings emphasize the importance of considering substrate size distribution in models for objects impacting granular asteroid surfaces.
Article
Astronomy & Astrophysics
Yangyuxin Zou, Luke Chamandy, Jonathan Carroll-Nellenback, Eric G. Blackman, Adam Frank
Summary: This study investigates the effects of jet feedback on the orbital evolution and envelope unbinding process during a common envelope (CE) event. The results show that jets can efficiently transfer energy to bound envelope material, leading to an increase in unbound mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Multidisciplinary
Damian Radoslaw Sowinski, Jonathan Carroll-Nellenback, Jeremy DeSilva, Adam Frank, Gourab Ghoshal, Marcelo Gleiser
Summary: Agents interacting with their environments make decisions based on their limited access to data and cognitive limitations, leading to different conclusions and actions. This has a significant impact on polities based on information sharing and can result in a consensus problem.
Article
Astronomy & Astrophysics
Max Neiderbach, Bingcheng Suo, Esteban Wright, A. C. Quillen, Mokin Lee, Peter Miklavcic, Hesam Askari, Paul Sanchez
Summary: High speed videos are used in laboratory experiments to observe particle motions caused by low velocity impact into sand. Particle displacements are measured using particle tracking velocimetry and cross-correlation method. The ratio of final particle displacement to crater radius is similar to other impact craters.
Article
Physics, Fluids & Plasmas
R. N. Markwick, A. Frank, J. Carroll-Nellenback, E. G. Blackman, P. M. Hartigan, S. V. Lebedev, D. R. Russell, J. W. D. Halliday, L. G. Suttle
Summary: By simulating and studying the bow shock formed by the collision of hypersonic flows, it is found that the motion of the interaction region is driven by imbalances in ram pressure between the two flows, and the conical structure of the bow shock is a result of deflected lateral outflows when the flows have differing cross sections.
PHYSICS OF PLASMAS
(2022)
Article
Physics, Multidisciplinary
Abraham Chien, Lan Gao, Shu Zhang, Hantao Ji, Eric G. Blackman, William Daughton, Adam Stanier, Ari Le, Fan Guo, Russ Follett, Hui Chen, Gennady Fiksel, Gabriel Bleotu, Robert C. Cauble, Sophia N. Chen, Alice Fazzini, Kirk Flippo, Omar French, Dustin H. Froula, Julien Fuchs, Shinsuke Fujioka, Kenneth Hill, Sallee Klein, Carolyn Kuranz, Philip Nilson, Alexander Rasmus, Ryunosuke Takizawa
Summary: Laboratory experiments confirm that electrons can be accelerated to high energies by the reconnection electric field in magnetically driven reconnection. This mechanism is important in various astrophysical environments. However, none of the proposed reconnection acceleration mechanisms have been experimentally confirmed due to measurement limitations.
Article
Astronomy & Astrophysics
Eric G. Blackman, Sergey V. Lebedev
Summary: The physics of astrophysical jets can be divided into three stages, and experiments are commonly used tools in studying them. However, due to the lack of specialized experimental tools for jet research, experiments have not yet solved astrophysical jet mysteries on their own.
NEW ASTRONOMY REVIEWS
(2022)
Article
Physics, Fluids & Plasmas
A. Lees, R. Betti, J. P. Knauer, V. Gopalaswamy, D. Patel, K. M. Woo, K. S. Anderson, E. M. Campbell, D. Cao, J. Carroll-Nellenback, R. Epstein, C. J. Forrest, V. N. Goncharov, D. R. Harding, S. X. Hu, I. V. Igumenshchev, R. T. Janezic, O. M. Mannion, P. B. Radha, S. P. Regan, A. Shvydky, R. C. Shah, W. T. Shmayda, C. Stoeckl, W. Theobald, C. A. Thomas
Summary: A physics-based statistical mapping approach was used to extract and quantify the major sources of degradation of fusion yield in direct-drive implosions on the OMEGA laser. The yield was found to be dependent on the age of the fill, implosion core asymmetry, laser beam-to-target size ratio, and hydrodynamic stability parameters. A new implosion design was created, guided by the mapping model, resulting in increased fusion yield in targets with larger diameters.
PHYSICS OF PLASMAS
(2023)
Article
Astronomy & Astrophysics
Adam E. Rubinstein, Nicole Karnath, Alice C. Quillen, Samuel Federman, Joel D. Green, Edward T. Chambers, Dan M. Watson, S. Thomas Megeath
Summary: This study presents a two-epoch Hubble Space Telescope observation of NGC 2071 IR, focusing on HOPS 361-C, a protostar that exhibits a curved jet with a scale of 0.2 parsecs. The proper motions of the knots in the jet decrease with increasing distance from the source, and the velocity jump through each knot is estimated to be around 40-50 km/s. The observations further suggest a precessing jet model with a precession period of 1000-3000 years and a half opening angle of 15 degrees.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Multidisciplinary
Shu Zhang, Abraham Chien, Lan Gao, Hantao Ji, Eric G. Blackman, Russ Follett, Dustin H. Froula, Joseph Katz, Chikang Li, Andrew Birkel, Richard Petrasso, John Moody, Hui Chen
Summary: Magnetic reconnection converts magnetic energy into thermal and kinetic energy in plasma. Ion acoustic bursts followed by electron acoustic bursts are observed in a laboratory experiment, indicating the importance of ion and electron acoustic dynamics during reconnection.
Article
Physics, Fluids & Plasmas
H. Yin, J. K. Shang, E. G. Blackman, G. W. Collins, H. Aluie
Summary: This study demonstrates a methodology for diagnosing multiscale dynamics and energy transfer in complex HED flows, and applies it to compare kinetic energy transfer in 2D and 3D laser-driven plasma jet simulations. It reveals a spurious energy issue in 2D modeling that is absent in the 3D model.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
A. C. Quillen
Summary: Biological systems can use the collective formation of a metachronal wave to achieve locomotion and fluid transport. One-dimensional chains of phase oscillators connected in a loop with rotational symmetry can exhibit instability to short wavelength perturbations, leading to changes in the metachronal wave speed. Stochastic phase oscillator models also show that even weak noise can induce instabilities that result in metachronal wave states.