Shock finding on a moving-mesh

• Verfasst von: Schaal, Kevin [VerfasserIn]
• Verfasst von: Springel, Volker [VerfasserIn]
• Verfasst von: Pakmor, Rüdiger [VerfasserIn]
• Verfasst von: Pfrommer, Christoph [VerfasserIn]
• Titel: Shock finding on a moving-mesh
• Titelzusatz: II. Hydrodynamic shocks in the Illustris universe
• Verf.angabe: Kevin Schaal, Volker Springel, Rüdiger Pakmor, Christoph Pfrommer, Dylan Nelson, Mark Vogelsberger, Shy Genel, Annalisa Pillepich, Debora Sijacki and Lars Hernquist
• E-Jahr: 2016
• Jahr: 04 July 2016
• Umfang: 25 S.
• Fussnoten: Gesehen am 06.11.2017
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2016
• Band/Heft Quelle: 461(2016), 4, Seite 4441-4465
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stw1587
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1565001567

Abstract

Hydrodynamical shocks are a manifestation of the non-linearity of the Euler equations and play a fundamental role in cosmological gas dynamics. In this work, we identify and analyse shocks in the Illustris simulation, and contrast the results with those of non-radiative runs. We show that simulations with more comprehensive physical models of galaxy formation pose new challenges for shock finding algorithms due to radiative cooling and star-forming processes, prompting us to develop a number of methodology improvements. We find in Illustris a total shock surface area which is about 1.4 times larger at the present epoch compared to non-radiative runs, and an energy dissipation rate at shocks which is higher by a factor of around 7. Remarkably, shocks with Mach numbers above and below $$\mathcal {M}\approx 10$$ contribute about equally to the total dissipation across cosmic time. This is in sharp contrast to non-radiative simulations, and we demonstrate that a large part of the difference arises due to strong black hole radio-mode feedback in Illustris. We also provide an overview of the large diversity of shock morphologies, which includes complex networks of halo-internal shocks, shocks on to cosmic sheets, feedback shocks due to black holes and galactic winds, as well as ubiquitous accretion shocks. In high-redshift systems more massive than 1012 M⊙, we discover the existence of a double accretion shock pattern in haloes. They are created when gas streams along filaments without being shocked at the outer accretion shock, but then forms a second, roughly spherical accretion shock further inside.