scholarly journals Three-dimensional Boltzmann-hydro Code for Core-collapse in Massive Stars. III. A New Method for Momentum Feedback from Neutrino to Matter

2019 ◽  
Vol 878 (2) ◽  
pp. 160 ◽  
Author(s):  
Hiroki Nagakura ◽  
Kohsuke Sumiyoshi ◽  
Shoichi Yamada
Keyword(s):  
Massive Stars ◽  
Three Dimensional ◽  
New Method ◽  
Core Collapse

scholarly journals Three-dimensional Boltzmann-Hydro Code for Core-collapse in Massive Stars. II. The Implementation of Moving-mesh for Neutron Star Kicks

2017 ◽  
Vol 229 (2) ◽  
pp. 42 ◽  
Author(s):  
Hiroki Nagakura ◽  
Wakana Iwakami ◽  
Shun Furusawa ◽  
Kohsuke Sumiyoshi ◽  
Shoichi Yamada ◽  
...  
Keyword(s):  
Neutron Star ◽  
Massive Stars ◽  
Three Dimensional ◽  
Moving Mesh ◽  
Core Collapse

scholarly journals The mechanism(s) of core-collapse supernovae

2017 ◽  
Vol 375 (2105) ◽  
pp. 20160271 ◽  
Author(s):  
Sean M. Couch
Keyword(s):  
Massive Stars ◽  
Three Dimensional ◽  
Short Review ◽  
Core Collapse ◽  
The Impact ◽  
Three Dimensional Simulations

Core-collapse supernovae (CCSNe) are the explosions that attend the deaths of massive stars. Despite decades of research, several aspects of the mechanism that drives these explosions remain uncertain and the subjects of continued investigation. In this short review, I will give an overview of the CCSN mechanism and current research in the field. In particular, I will focus on recent results from three-dimensional simulations and the impact of turbulence and detailed non-spherical progenitor structure on CCSNe. This contribution is based on a talk given at the ‘Bridging the Gap’ workshop at Chicheley Hall on 2 June 2016. This article is part of the themed issue ‘Bridging the gap: from massive stars to supernovae’.

scholarly journals Spectropolarimetry of stripped-envelope supernovae: observations and modelling

2017 ◽  
Vol 375 (2105) ◽  
pp. 20160273 ◽  
Author(s):  
Masaomi Tanaka
Keyword(s):  
Large Scale ◽  
Massive Stars ◽  
Three Dimensional ◽  
Core Collapse ◽  
Ion Distribution ◽  
Typical Size ◽  
Cassiopeia A ◽  
Accretion Shock

Spectropolarimetry is one of the most powerful methods to study the multi-dimensional geometry of supernovae (SNe). We present a brief summary of the spectropolarimetric observations of stripped-envelope core-collapse SNe. Observations indicate that stripped-envelope SNe generally have a non-axisymmetric ion distribution in the ejecta. Three-dimensional clumpy geometry nicely explains the observed properties. A typical size of the clumps deduced from observations is relatively large: 25% of the photosphere. Such a large-scale clumpy structure is similar to that observed in Cassiopeia A, and suggests that large-scale convection or standing accretion shock instability takes place at the onset of the explosion. This article is part of the themed issue ‘Bridging the gap: from massive stars to supernovae’.

scholarly journals One-, Two-, and Three-dimensional Simulations of Oxygen-shell Burning Just before the Core Collapse of Massive Stars

2019 ◽  
Vol 881 (1) ◽  
pp. 16 ◽  
Author(s):  
Takashi Yoshida ◽  
Tomoya Takiwaki ◽  
Kei Kotake ◽  
Koh Takahashi ◽  
Ko Nakamura ◽  
...  
Keyword(s):  
Massive Stars ◽  
Three Dimensional ◽  
Core Collapse ◽  
The Core ◽  
Three Dimensional Simulations

scholarly journals The Three-dimensional Collapse of a Rapidly Rotating 16 M ⊙ Star

2022 ◽  
Vol 924 (1) ◽  
pp. L15
Author(s):  
C. E. Fields
Keyword(s):  
Massive Stars ◽  
Gravitational Instability ◽  
Three Dimensional ◽  
Iron Core ◽  
Core Collapse ◽  
Hydrodynamic Evolution ◽  
Tightly Coupled ◽  
Critical Components ◽  
Rotating Shell ◽  
First Time

Abstract I report on the three-dimensional (3D) hydrodynamic evolution of a rapidly rotating 16 M ⊙ star to iron core collapse. For the first time, I follow the 3D evolution of the angular momentum (AM) distribution in the iron core and convective shell burning regions for the final 10 minutes up to and including gravitational instability and core collapse. In 3D, convective regions show efficient AM transport that leads to an AM profile that differs in shape and magnitude from MESA within a few shell convective turnover timescales. For different progenitor models, such as those with tightly coupled Si/O convective shells, efficient AM transport in 3D simulations could lead to a significantly different AM distribution in the stellar interior affecting estimates of the natal neutron star or black hole spin. The results suggest that 3D AM transport in convective and rotating shell burning regions are critical components in models of massive stars and could qualitatively alter the explosion outcome and inferred compact remnant properties.

scholarly journals A New Method to Evaluate Trueness and Precision of Digital and Conventional Impression Techniques for Complete Dental Arch

2021 ◽  
Vol 11 (10) ◽  
pp. 4612
Author(s):  
KweonSoo Seo ◽  
Sunjai Kim
Keyword(s):  
Intraclass Correlation ◽  
Three Dimensional ◽  
New Method ◽  
Digital Impression ◽  
Dental Arch ◽  
Digital Models ◽  
Digital Impressions ◽  
Measuring Machine ◽  
Master Model ◽  
Conventional Impression

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twenty-five definitive stone casts were fabricated using conventional impressions of the master model. An intraoral scanner was used to scan the master model 25 times to fabricate 25 digital models. A coordinate measuring machine was used to physically probe each cylinder in the master model and definitive casts. An inspection software was used to probe cylinders of digital models. A three-dimensional part coordinate system was defined and used to compute the centroid coordinate of each cylinder. Intraclass correlation coefficient (ICC) was evaluated to examine the reliability of the new method. Independent two sample t-test was performed to compare the trueness and precision of conventional and intraoral digital impressions (α = 0.05). Results: ICC results showed that, the new method had almost perfect reliability for the measurements of the master model, conventional and digital impression. Conventional impression showed more accurate absolute trueness and precision than intraoral digital impression for most of the tooth positions (p < 0.05). Conclusions: The new method was reliable to analyze the three-dimensional deviation of complete-arch impressions. Conventional impression was still more accurate than digital intraoral impression for complete arches.

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