scholarly journals Black Hole Disk Accretion in Supernovae

1998 ◽  
Vol 188 ◽  
pp. 243-244
Author(s):  
H. Nomura ◽  
S. Mineshige ◽  
M. Hirose ◽  
K. Nomoto ◽  
T. Suzuki
Keyword(s):  
Black Hole ◽  
Massive Stars ◽  
Mass Range ◽  
Disk Accretion ◽  
Reverse Shock ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Smoothed Particle Hydrodynamics Method ◽  
Supernova Explosions ◽  
Low Mass

Massive stars in a certain mass range (20 – 40M⊙) may form low mass black holes after supernova explosions. In such massive stars, fall back of ~ 0.1M⊙ materials onto a black hole is expected due to a deep gravitational potential or a reverse shock propagating back from the outer composition interface. We study hydrodynamical disk accretion onto a new-born low mass black hole in a supernova using the SPH (Smoothed Particle Hydrodynamics) method.

scholarly journals Hydrostatic mass estimates of massive galaxy clusters: a study with varying hydrodynamics flavours and non-thermal pressure support

2019 ◽  
Vol 491 (2) ◽  
pp. 1622-1642 ◽  
Author(s):  
Francesca A Pearce ◽  
Scott T Kay ◽  
David J Barnes ◽  
Richard G Bower ◽  
Matthieu Schaller
Keyword(s):  
Simulated Data ◽  
Mass Range ◽  
Sph Method ◽  
Thermal Pressure ◽  
The Bahamas ◽  
Density Profiles ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Low Mass ◽  
Massive Clusters

ABSTRACT We use a set of 45 simulated clusters with a wide mass range (8 × 1013 < M500 [M⊙] < 2 × 1015) to investigate the effect of varying hydrodynamics flavours on cluster mass estimates. The cluster zooms were simulated using the same cosmological models as the BAHAMAS and C-EAGLE projects, leading to differences in both the hydrodynamics solvers and the subgrid physics but still producing clusters that broadly match observations. At the same mass resolution as BAHAMAS, for the most massive clusters (M500 > 1015 M⊙), we find that changes in the smoothed particle hydrodynamics (SPH) method produce the greatest differences in the final halo, while the subgrid models dominate at lower mass. By calculating the mass of all of the clusters using different permutations of the pressure, temperature, and density profiles, created with either the true simulated data or mock spectroscopic data, we find that the spectroscopic temperature causes a bias in the hydrostatic mass estimates that increases with the mass of the cluster, regardless of the SPH flavour used. For the most massive clusters, the estimated mass of the cluster using spectroscopic density and temperature profiles is found to be as low as 50 per cent of the true mass compared to ∼90 per cent for low-mass clusters. When including a correction for non-thermal pressure, the spectroscopic hydrostatic mass estimates are less biased on average and the mass dependence of the bias is reduced, although the scatter in the measurements does increase.

scholarly journals The Role of Discs in the Collapse and Fragmentation of Prestellar Cores

2016 ◽  
Vol 33 ◽  
Author(s):  
O. Lomax ◽  
A. P. Whitworth ◽  
D. A. Hubber
Keyword(s):  
Kinetic Energy ◽  
Smoothed Particle Hydrodynamics ◽  
Low Mass Stars ◽  
Gravitational Instabilities ◽  
Disc Material ◽  
Prestellar Cores ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Low Mass

AbstractDisc fragmentation provides an important mechanism for producing low-mass stars in prestellar cores. Here, we describe smoothed particle hydrodynamics simulations which show how populations of prestellar cores evolve into stars. We find the observed masses and multiplicities of stars can be recovered under certain conditions.First, protostellar feedback from a star must be episodic. The continuous accretion of disc material on to a central protostar results in local temperatures which are too high for disc fragmentation. If, however, the accretion occurs in intense outbursts, separated by a downtime of ~ 104yr, gravitational instabilities can develop and the disc can fragment.Second, a significant amount of the cores’ internal kinetic energy should be in solenoidal turbulent modes. Cores with less than a third of their kinetic energy in solenoidal modes have insufficient angular momentum to form fragmenting discs. In the absence of discs, cores can fragment but results in a top-heavy distribution of masses with very few low-mass objects.

scholarly journals Supernovae from massive stars with extended tenuous envelopes

2018 ◽  
Vol 612 ◽  
pp. A61 ◽  
Author(s):  
Luc Dessart ◽  
Sung-Chul Yoon ◽  
Eli Livne ◽  
Roni Waldman
Keyword(s):  
Massive Stars ◽  
Constant Width ◽  
Core Material ◽  
Close Binary ◽  
Reverse Shock ◽  
Halo Structure ◽  
Deposited Energy ◽  
Dense Shell ◽  
Low Mass ◽  
Binary Evolution

Massive stars with a core-halo structure are interesting objects for stellar physics and hydrodynamics. Using simulations for stellar evolution, radiation hydrodynamics, and radiative transfer, we study the explosion of stars with an extended and tenuous envelope (i.e. stars in which 95% of the mass is contained within 10% or less of the surface radius). We consider both H-rich supergiant and He-giant progenitors resulting from close-binary evolution and dying with a final mass of 2.8–5 M⊙. An extended envelope causes the supernova (SN) shock to brake and a reverse shock to form, sweeping core material into a dense shell. The shock-deposited energy, which suffers little degradation from expansion, is trapped in ejecta layers of moderate optical depth, thereby enhancing the SN luminosity at early times. With the delayed 56Ni heating, we find that the resulting optical and near-IR light curves all exhibit a double-peak morphology. We show how an extended progenitor can explain the blue and featureless optical spectra of some Type IIb and Ib SNe. The dense shell formed by the reverse shock leads to line profiles with a smaller and near-constant width. This ejecta property can explain the statistically narrower profiles of Type IIb compared to Type Ib SNe, as well as the peculiar Hα profile seen in SN 1993J. At early times, our He-giant star explosion model shows a high luminosity, a blue colour, and featureless spectra reminiscent of the Type Ib SN 2008D, suggesting a low-mass progenitor.

Sign in / Sign up

Export Citation Format

Share Document