scholarly journals A common origin for the circumnuclear disc and the nearby molecular clouds in the Galactic Centre

2019 ◽  
Vol 488 (4) ◽  
pp. 5802-5810 ◽  
Author(s):  
Alessandro Ballone ◽  
Michela Mapelli ◽  
Alessandro Alberto Trani
Keyword(s):  
Star Formation ◽  
Molecular Cloud ◽  
Adaptive Mesh Refinement ◽  
Molecular Clouds ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Common Origin ◽  
Galactic Centre ◽  
Tidal Disruption ◽  
Hydrodynamic Simulation

ABSTRACT The origin of the molecular clouds orbiting SgrA* is one of the most debated questions about our Galactic Centre. Here, we present the hydrodynamic simulation of a molecular cloud infalling towards SgrA*, performed with the adaptive-mesh-refinement code ramses. Through such simulation, we propose that the circumnuclear disc and the +20 km s−1 cloud originated from the same tidal disruption episode, occurred less than 1 Myr ago. We also show that recent star formation is to be expected in the +20 km s−1 cloud, as also suggested by recent observations.

scholarly journals Cosmological simulations of low-mass galaxies: some potential issues

2010 ◽  
Vol 6 (S270) ◽  
pp. 503-506
Author(s):  
Pedro Colín ◽  
Vladimir Avila-Reese ◽  
Octavio Valenzuela
Keyword(s):  
Star Formation ◽  
Adaptive Mesh Refinement ◽  
Mass Fraction ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Stellar Mass ◽  
The Galaxy ◽  
Low Mass

AbstractCosmological Adaptive Mesh Refinement simulations are used to study the specific star formation rate (sSFR=SSF/Ms) history and the stellar mass fraction, fs=Ms/MT, of small galaxies, total masses MT between few × 1010 M⊙ to few ×1011 M⊙. Our results are compared with recent observational inferences that show the so-called “downsizing in sSFR” phenomenon: the less massive the galaxy, the higher on average is its sSFR, a trend seen at least since z ~ 1. The simulations are not able to reproduce this phenomenon, in particular the high inferred values of sSFR, as well as the low values of fs constrained from observations. The effects of resolution and sub-grid physics on the SFR and fs of galaxies are discussed.

scholarly journals Adaptive Mesh Refinement for Supersonic Molecular Cloud Turbulence

2006 ◽  
Vol 638 (1) ◽  
pp. L25-L28 ◽  
Author(s):  
Alexei G. Kritsuk ◽  
Michael L. Norman ◽  
Paolo Padoan
Keyword(s):  
Molecular Cloud ◽  
Adaptive Mesh Refinement ◽  
Mesh Refinement ◽  
Adaptive Mesh

Self‐gravitational Hydrodynamics with Three‐dimensional Adaptive Mesh Refinement: Methodology and Applications to Molecular Cloud Collapse and Fragmentation

1998 ◽  
Vol 495 (2) ◽  
pp. 821-852 ◽  
Author(s):  
J. Kelly Truelove ◽  
Richard I. Klein ◽  
Christopher F. McKee ◽  
John H. Holliman II ◽  
Louis H. Howell ◽  
...  
Keyword(s):  
Molecular Cloud ◽  
Adaptive Mesh Refinement ◽  
Mesh Refinement ◽  
Three Dimensional ◽  
Adaptive Mesh

scholarly journals Achieving Extreme Resolution in Numerical Cosmology Using Adaptive Mesh Refinement: Resolving Primordial Star Formation

2002 ◽  
Vol 10 (4) ◽  
pp. 291-302
Author(s):  
Greg L. Bryan ◽  
Tom Abel ◽  
Michael L. Norman
Keyword(s):  
Star Formation ◽  
Adaptive Mesh Refinement ◽  
Dynamic Range ◽  
Parallel Implementation ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Local Refinement ◽  
First Stars ◽  
Standard Cosmological Model ◽  
The Universe

As an entry for the 2001 Gordon Bell Award in the "special" category, we describe our 3-d, hybrid, adaptive mesh refinement (AMR) codeEnzodesigned for high-resolution, multiphysics, cosmological structure formation simulations. Our parallel implementation places no limit on the depth or complexity of the adaptive grid hierarchy, allowing us to achieve unprecedented spatial and temporal dynamic range. We report on a simulation of primordial star formation which develops over 8000 subgrids at 34 levels of refinement to achieve a local refinement of a factor of 1012in space and time. This allows us to resolve the properties of the first stars which form in the universe assuming standard physics and a standard cosmological model. Achievingextreme resolutionrequires the use of 128-bit extended precision arithmetic (EPA) to accurately specify the subgrid positions. We describe our EPA AMR implementation on the IBM SP2 Blue Horizon system at the San Diego Supercomputer Center.

scholarly journals Numerical simulation of star formation in filamentary dark molecular clouds

2015 ◽  
Vol 11 (S315) ◽  
pp. 103-106
Author(s):  
Pak Shing Li ◽  
Richard I. Klein ◽  
Christopher F. McKee
Keyword(s):  
Magnetic Field ◽  
Star Formation ◽  
Numerical Simulations ◽  
Adaptive Mesh Refinement ◽  
Molecular Clouds ◽  
Dynamic Range ◽  
Adaptive Mesh ◽  
Mass Function ◽  
Dark Cloud ◽  
Scale Down

AbstractNumerical simulations of star formation faces challenges including the huge spatial dynamic range and the presence of multiply coupled highly non-linear physics, such as magnetic field, supersonic turbulence, gravitation, radiation and protostellar outflow feedback. We present in this symposium our latest high resolution adaptive mesh refinement numerical simulations of the formation of filamentary dark molecular clouds from 4.55 pc size scale down to the formation of a protostellar cluster with maximum resolution at 28 AU. The physical properties of the long braided filamentary dark cloud formed in the simulation, the magnetic field properties of the cloud clumps, and the protostellar mass function in the simulations match well with the latest observations.

scholarly journals Star Formation with Adaptive Mesh Refinement Radiation Hydrodynamics

2010 ◽  
Vol 6 (S270) ◽  
pp. 187-194
Author(s):  
Mark R. Krumholz
Keyword(s):  
Star Formation ◽  
Adaptive Mesh Refinement ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Radiation Hydrodynamics ◽  
Adaptive Grids ◽  
Advantages And Disadvantages ◽  
Approximate Equations ◽  
Numerical Approaches

AbstractI provide a pedagogic review of adaptive mesh refinement (AMR) radiation hydrodynamics (RHD) methods and codes used in simulations of star formation, at a level suitable for researchers who are not computational experts. I begin with a brief overview of the types of RHD processes that are most important to star formation, and then I formally introduce the equations of RHD and the approximations one uses to render them computationally tractable. I discuss strategies for solving these approximate equations on adaptive grids, with particular emphasis on identifying the main advantages and disadvantages of various approximations and numerical approaches. Finally, I conclude by discussing areas ripe for improvement.

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