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Related papers: Numerical overcooling in shocks

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The absence of large cooling flows in cool core clusters appears to require self-regulated energy feedback by active galactic nuclei (AGNs) but the exact heating mechanism has not yet been identified. Here, we analyse whether a combination…

Astrophysics of Galaxies · Physics 2017-04-27 Svenja Jacob , Christoph Pfrommer

We compare the results of two techniques used to calculate the evolution of cooling gas during galaxy formation: Smooth Particle Hydrodynamics (SPH) simulations and semi-analytic modelling. We improve upon the earlier statistical comparison…

We have analysed two cosmological zoom simulations with $M_{\rm vir}\sim 10^{12}{\rm\,M}_\odot$ from the NIHAO series, both with and without feedback. We show that an entropy criterion based on the equation of state of the intergalactic…

Astrophysics of Galaxies · Physics 2022-07-20 Édouard Tollet , Andrea Cattaneo , Andrea V. Macciò , Xi Kang

Performing a stable, long duration simulation of driven MHD turbulence with a high thermal Mach number and a strong initial magnetic field is a challenge to high-order Godunov ideal MHD schemes because of the difficulty in guaranteeing…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Pak Shing Li , Daniel F. Martin , Richard I. Klein , Christopher F. McKee

Recent three-dimensional cosmological simulations of protogalaxy formation have suggested that supermassive stars (SMSs) can form in gas clouds in which H$_2$ cooling is suppressed by dynamical heating prior to the activation of atomic…

Astrophysics of Galaxies · Physics 2020-10-28 Yuya Sakurai , Zoltán Haiman , Kohei Inayoshi

We compare the mass cooling rates and cumulative cooled-down masses predicted by several semi-analytical (SA) cooling models with cosmological hydrodynamical simulations performed using the AREPO code (ignoring processes such as feedback…

Astrophysics of Galaxies · Physics 2019-03-20 Jun Hou , Cedric G. Lacey , Carlos. S. Frenk

An implicit method for radiative transfer in SPH is described. The diffusion approximation is used, and the hydrodynamic calculations are performed by a fully three--dimensional SPH code. Instead of the energy equation of state for an ideal…

Astrophysics · Physics 2009-11-11 Serge Viau , Pierre Bastien , Seung-Hoon Cha

We present a new version of the MURaM radiative MHD code that allows for simulations spanning from the upper convection zone into the solar corona. We implemented the relevant coronal physics in terms of optically thin radiative loss, field…

Solar and Stellar Astrophysics · Physics 2016-12-28 Matthias Rempel

We describe an implicit 1--D adaptive mesh hydrodynamics code that is specially tailored for radial stellar pulsations. In the Lagrangean limit the code reduces to the well tested Fraley scheme. The code has the useful feature that…

Astrophysics · Physics 2009-10-30 J. Robert Buchler , Zoltan Kollath , Ariel Marom

We compare the structural properties of galaxies formed in cosmological simulations using the smoothed particle hydrodynamics (SPH) code GADGET with those using the moving-mesh code AREPO. Both codes employ identical gravity solvers and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Paul Torrey , Mark Vogelsberger , Debora Sijacki , Volker Springel , Lars Hernquist

The problem of a non-steady planar radiation mediated shock (RMS) breaking out from a surface with a power-law density profile, \rho\propto x^n, is numerically solved in the approximation of diffusion with constant opacity. For an…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Nir Sapir , Boaz Katz , Eli Waxman

Atomic physics calculations of radiative cooling are used to calculate criteria for the overstability of radiating shocks. Our calculations explain the measurement of shock overstability by Grun et al. and explain why the overstability was…

Astrophysics · Physics 2009-11-07 J. Martin Laming , Jacob Grun

We present a novel numerical implementation of radiative transfer in the cosmological smoothed particle hydrodynamics (SPH) simulation code {\small GADGET}. It is based on a fast, robust and photon-conserving integration scheme where the…

Astrophysics · Physics 2009-06-23 M. Petkova , V. Springel

Laser cooling of solids currently has a temperature floor of 50 - 100 K. We propose a method that could overcome this using defects, such as diamond color centers, with narrow electronic manifolds and bright optical transitions. It exploits…

Mesoscale and Nanoscale Physics · Physics 2024-10-08 Luisa Toledo Tude , Conor N. Murphy , Paul R. Eastham

We compare two techniques for following the cooling of gas and its condensation into galaxies within high resolution simulations of cosmologically representative regions. Both techniques treat the dark matter using N-body methods. One…

Astrophysics · Physics 2009-09-25 Naoki Yoshida , Felix Stoehr , Volker Springel , Simon D. M. White

We study the long-term evolution of an idealized cool-core galaxy cluster under the influence of momentum-driven AGN feedback using three-dimensional high-resolution (60 pc) adaptive mesh refinement (AMR) simulations. The momentum-driven…

Astrophysics of Galaxies · Physics 2015-06-18 Yuan Li , Greg L. Bryan

Context: There is a need to improve the fidelity of SPH simulations of self-gravitating gas dynamics. Aims: We remind users of SPH that, if smoothing lengths are adjusted so as to keep the number of neighbours, ${\cal N}$, in the range…

Astrophysics · Physics 2015-06-24 R. E. Attwood , S. P. Goodwin , A. P. Whitworth

Direct numerical simulation of subsonic turbulence with smoothed particle hydrodynamics (SPH) has traditionally been hampered by zeroth-order (E0) errors, inaccurate gradient evaluations, and excessive numerical dissipation. We demonstrate…

Supermassive stars (SMSs) and heavy seed black holes, as their remnants, are promising candidates for Supermassive Black Hole (SMBH) progenitors, especially for ones observed in the early universe $ z\simeq 8.5-10$ by recent JWST…

Astrophysics of Galaxies · Physics 2024-10-21 Masaki Kiyuna , Takashi Hosokawa , Sunmyon Chon

HD dominates the cooling of primordial clouds with enhanced ionization, e.g. shock-heated clouds in structure formation or supernova remnants, relic HII regions of Pop III stars, and clouds with cosmic-ray (CR) irradiation. There, the…

Astrophysics of Galaxies · Physics 2015-06-19 Daisuke Nakauchi , Kohei Inayoshi , Kazuyuki Omukai
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