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Related papers: Dense and diffuse gas in dynamically active clouds

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A large fraction of the gas in the Galaxy is cold, dense, and molecular. If all this gas collapsed under the influence of gravity and formed stars in a local free-fall time, the star formation rate in the Galaxy would exceed that observed…

Astrophysics of Galaxies · Physics 2017-10-04 Mordecai-Mark Mac Low , Andreas Burkert , Juan C. Ibáñez-Mejía

The chemistry of molecular clouds has been studied for decades, with an increasingly general and sophisticated treatment of the reactions involved. Yet the treatment of turbulent diffusion has remained extremely sketchy, assuming simple…

Astrophysics · Physics 2009-06-23 G. Marschalko , K. Petrovay , E. Forgacs-Dajka

We present synthetic line observations of a simulated molecular cloud, utilising a self-consistent treatment of the dynamics and time-dependent chemical evolution. We investigate line emission from the three most common CO isotopologues…

Astrophysics of Galaxies · Physics 2024-06-12 F. D. Priestley , P. C. Clark , S. C. O. Glover , S. E. Ragan , O. Fehér , L. R. Prole , R. S. Klessen

We examine the formation of molecular gas behind shocks in atomic gas using a chemical/dynamical model, particular emphasis is given to constraints the chemistry places on the dynamical evolution. The most important result of this study is…

Hot core molecules should be detectable in external active galaxies out to high redshift. We present here a detailed study of the chemistry of star-forming regions under physical conditions that differ significantly from those likely to be…

Astrophysics · Physics 2009-11-13 E. Bayet , S. Viti , D. A. Williams , J. M. C. Rawlings

Observations that resolve nearby galaxies into individual regions across multiple phases of the gas-star formation-feedback ``matter cycle'' have provided a sharp new view of molecular clouds, star formation efficiencies, timescales for…

Astrophysics of Galaxies · Physics 2024-04-01 Eva Schinnerer , Adam K. Leroy

We show how the mass function of dense cores (CMF) which results from the gravoturbulent fragmentation of a molecular cloud evolves in time under the effect of gas accretion. Accretion onto the cores leads to the formation of larger numbers…

Astrophysics of Galaxies · Physics 2012-07-23 Sami Dib

We study effect of magnetic field on massive dense core formation in colliding unequal molecular clouds by performing magnetohydrodynamic simulations with sub-parsec resolution (0.015 pc) that can resolve the molecular cores. Initial clouds…

Astrophysics of Galaxies · Physics 2020-07-23 Nirmit Sakre , Asao Habe , Alex R. Pettitt , Takashi Okamoto

Recent statistical analysis of two extragalactic observational surveys strongly indicate a sublinear Kennicutt-Schmidt (KS) relationship between the star formation rate (Sigsfr) and molecular gas surface density (Sigmol). Here, we consider…

Astrophysics of Galaxies · Physics 2015-06-19 Rahul Shetty , Paul C. Clark , Ralf S. Klessen

Hot molecular cores (HMCs) are intermediate stages of high-mass star formation and are also known for their rich emission line spectra at (sub-)mm wavebands. The observed spectral feature of HMCs such as total number of emission lines and…

We present the results from three dimensional hydrodynamical simulations of decaying high-speed turbulence in dense molecular clouds. We compare our results, which include a detailed cooling function, molecular hydrogen chemistry and a…

Astrophysics · Physics 2009-11-07 Georgi Pavlovski , Michael D. Smith , Mordecai-Mark Mac Low , Alexander Rosen

We simulate the formation of molecular clouds in colliding flows of warm neutral medium with the adaptive mesh refinement code {\sc Flash}. We include a chemical network to treat heating and cooling and to follow the formation of molecular…

Astrophysics of Galaxies · Physics 2022-08-26 Michael Weis , Stefanie Walch , Daniel Seifried , Shashwata Ganguly

We use passive gas tracer particles in an Arepo simulation of a dwarf spiral galaxy to relate the Lagrangian evolution of star-forming gas parcels and their H2 molecules to the evolution of their host giant molecular clouds. We find that…

Astrophysics of Galaxies · Physics 2023-01-26 Sarah M. R. Jeffreson , Vadim A. Semenov , Mark R. Krumholz

A magnetohydrodynamic model of a steady, transverse C-type shock in a dense molecular cloud is presented. A complete gas-grain chemical network is taken into account: the gas-phase chemistry, the adsorption of gas species on dust grains,…

Astrophysics of Galaxies · Physics 2018-06-12 A. V. Nesterenok

Turbulence governs the fragmentation of molecular clouds and plays a pivotal role in star formation. The persistence of observed cloud turbulence suggests it does not decay significantly within the turnover timescale, implying a recurrent…

Astrophysics of Galaxies · Physics 2025-09-15 Shibo Yuan , Hua-Bai Li

This work explores the morphology and dynamical properties of cores within rich superclusters, highlighting their role as transitional structures in the large-scale structure of the Universe. Using projected and radial velocity…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-18 J. M. Zúñiga , C. A. Caretta , H. Andernach

Pre-stellar cores represent the earliest stage of the star- and planet-formation process. By characterizing the physical and chemical structure of these cores we can establish the initial conditions for star and planet formation and…

Astrophysics of Galaxies · Physics 2023-07-05 S. S. Jensen , S. Spezzano , P. Caselli , T. Grassi , T. Haugbølle

We study the kinematics of the dense gas of starless and protostellar cores traced by the N2D+(2-1), N2H+(1-0), DCO+(2-1), and H13CO+(1-0) transitions along the L1495 filament and the kinematic links between the cores and the surrounding…

Astrophysics of Galaxies · Physics 2018-09-12 A. Punanova , P. Caselli , J. E. Pineda , A. Pon , M. Tafalla , A. Hacar , L. Bizzocchi

Observational evidence seems to indicate that the depletion of interstellar carbon into dust shows rather wide variations and that carbon undergoes rather rapid recycling in the interstellar medium (ISM). Small hydrocarbon grains are…

We investigate the chemical evolution of complex organic molecules (COMs) in turbulent disks using gas-ice chemical reaction network simulations. We trace trajectories of dust particles considering advection, turbulent diffusion, gas drag,…

Earth and Planetary Astrophysics · Physics 2024-06-26 Taiki Suzuki , Kenji Furuya , Yuri Aikawa , Takashi Shibata , Liton Majumdar
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