English
Related papers

Related papers: W49A North - Global or Local or No Collapse?

200 papers

Inelastic collapse is found in a two-dimensional system of inelastic hard disks confined between two walls which act as an energy source. As the coefficient of restitution is lowered, there is a transition between a state containing small…

Soft Condensed Matter · Physics 2009-10-31 Jan Tobochnik

We present synthetic Hi and CO observations of a simulation of decaying turbulence in the thermally bistable neutral medium. We first present the simulation, with clouds initially consisting of clustered clumps. Self-gravity causes these…

Astrophysics of Galaxies · Physics 2015-08-06 Jonathan S. Heiner , Enrique Vázquez-Semadeni , Javier Ballesteros-Paredes

We present a study of the cold atomic hydrogen (HI) content of molecular clouds simulated within the SILCC-Zoom project. We produce synthetic observations of HI at 21 cm including HI self-absorption (HISA) and observational effects. We find…

Astrophysics of Galaxies · Physics 2022-03-14 D. Seifried , H. Beuther , S. Walch , J. Syed , J. D. Soler , P. Girichidis , R. Wünsch

Measuring isotopic ratios is a sensitive technique used to obtain information on stellar nucleosynthesis and chemical evolution. We present measurements of the carbon and sulphur abundances in the interstellar medium of the central region…

We report on high-angular resolution observations of a dense core in the cirrus cloud MCLD123.5+24.9 obtained with the PdB and the OVRO interferometers. Our maps show substructures down to the scale of the beam (~ 1000 AU). The chosen…

Astrophysics · Physics 2017-01-18 C. Boettner , A. Heithausen , F. Walter

We aim to better understand how the spatial structure of molecular clouds is governed by turbulence. For that, we study the large-scale spatial distribution of low density molecular gas and search for characteristic length scales. We employ…

Astrophysics of Galaxies · Physics 2015-05-18 N. Schneider , S. Bontemps , R. Simon , V. Ossenkopf , C. Federrath , R. Klessen , F. Motte , P. Andre , J. Stutzki , C. Brunt

Using the PMO-13.7 m millimeter telescope at Delingha in China, we have conducted a large-scale simultaneous survey of $^{12}$CO, $^{13}$CO, and C$^{18}$O $J=1-0$ emission toward the sky region centered at $l$=$209.7^\circ$,…

Astrophysics of Galaxies · Physics 2020-09-15 Chong Li , Hongchi Wang , Miaomiao Zhang , Yuehui Ma , Lianghao Lin

Spherical flows are a classic problem in astrophysics which are typically studied from a global perspective. However, much like with accretion discs, there are likely many instabilities and small scale phenomena which would be easier to…

Astrophysics of Galaxies · Physics 2023-08-02 Elliot M. Lynch , Guillaume Laibe

The Galactic Cold Cores (GCC) project has made Herschel observations of interstellar clouds where Planck detected compact sources of cold dust emission. Our aim is to characterise the structure of the clumps and their parent clouds. We also…

Astrophysics of Galaxies · Physics 2018-06-20 M. Juvela , J. Malinen , J. Montillaud , V. -M. Pelkonen , I. Ristorcelli , L. V. Toth

The high-velocity cloud (HVC) Complex A is a probe of the physical conditions in the Galactic halo. The kinematics, morphology, distance, and metallicity of Complex A indicate that it represents new material that is accreting onto the…

Astrophysics of Galaxies · Physics 2013-08-06 Kathleen A. Barger , Lawrence M. Haffner , Bart P. Wakker , Alex S. Hill , Greg J. Madsen , Allison K. Duncan

We present a study of the three-dimensional structure of the molecular clouds in the Galactic Centre (GC) using CO emission and OH absorption lines. Two CO isotopologue lines, $^{12}$CO ($J$=1$\rightarrow$0) and $^{13}$CO…

We present 3D "zoom-in" simulations of the formation of two molecular clouds out of the galactic interstellar medium. We model the clouds - identified from the SILCC simulations - with a resolution of up to 0.06 pc using adaptive mesh…

Astrophysics of Galaxies · Physics 2017-10-18 D. Seifried , S. Walch , P. Girichidis , T. Naab , R. Wünsch , R. S. Klessen , S. C. O. Glover , T. Peters , P. Clark

We introduce a model for the large-scale, global 3D structure of molecular clouds. Motivated by the morphological appearance of clouds in surface density maps, we model clouds as cylinders, with the aim of backing out information about the…

Astrophysics of Galaxies · Physics 2023-09-12 Nia Imara , John C. Forbes

We investigate protostellar collapse of molecular cloud cores by numerical simulations, taking into account turbulence and magnetic fields. By using the adaptive mesh refinement technique, the collapse is followed over a wide dynamic range…

Solar and Stellar Astrophysics · Physics 2015-05-19 Tomoaki Matsumoto , Tomoyuki Hanawa

We have analyzed HCN(1-0) and CS(2-1) line profiles obtained with high signal-to-noise ratios toward distinct positions in three selected objects in order to search for small-scale structure in molecular cloud cores associated with regions…

Astrophysics of Galaxies · Physics 2011-08-31 L. E. Pirogov , I. I. Zinchenko

We have mapped cold atomic gas in 21cm line HI self-absorption (HISA) at arcminute resolution over more than 90% of the Milky Way's disk. To probe the formation of H2 clouds, we have compared our HISA distribution with CO J=1-0 line…

We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting…

Observations of dust polarized emission toward star forming regions trace the magnetic field component in the plane of the sky and provide constraints to theoretical models of cloud collapse. We compare high-angular resolution observations…

Astrophysics of Galaxies · Physics 2015-05-30 Pau Frau , Daniele Galli , Josep Miquel Girart

We have performed two-dimensional hydrodynamic simulations of the collapse of isolated axisymmetric clouds condensing via radiative cooling in a primordial background gas. In order to study the development of the so-called…

Astrophysics · Physics 2009-11-07 Chang Hyun Baek , Hyesung Kang , Dongsu Ryu

Clouds more massive than about $10^5$ M$_\odot$ are potential sites of massive cluster formation. Studying the properties of such clouds in the early stages of their evolution offers an opportunity to test various cluster formation…

Astrophysics of Galaxies · Physics 2023-03-10 Vineet Rawat , M. R. Samal , D. L. Walker , A. Zavagno , A. Tej , G. Marton , D. K. Ojha , Davide Elia , W. P. Chen , J. Jose , C Eswaraiah