Zobrazeno 1 - 10
of 35
pro vyhledávání: '"Akiyama, Shizuka"'
Autor:
Akiyama, Shizuka
While the process that converts implosion into explosion in core collapse supernovae is poorly understood, their observed asphericity provides new constraints on the physics of these events. Since pulsars are rotating and magnetized neutron stars, th
Externí odkaz:
http://hdl.handle.net/2152/20984
Autor:
Akiyama, Shizuka, Salmonson, Jay D.
We performed 2D, axisymmetric, MHD simulations with Cosmos++ in order to examine the growth of the magnetorotational instability (MRI) in core--collapse supernovae. We have initialized a non--rotating 15 solar mass progenitor, infused with differenti
Externí odkaz:
http://arxiv.org/abs/1008.1422
Publikováno v:
Astrophys.J.688:L1-L5,2008
Recent theoretical studies have revealed the possibly important role of the capture and annihilation process of weakly interacting massive particles (WIMPs) for the first stars. Using new evolutionary models of metal-free massive stars, we investigat
Externí odkaz:
http://arxiv.org/abs/0806.2662
Publikováno v:
AIP Conf.Proc.1054:3-11,2008
We provide a brief review of the physical processes behind the radiative driving of the winds of OB stars and the Bondi-Hoyle-Lyttleton capture and accretion of a fraction of the stellar wind by a compact object, typically a neutron star, in detached
Externí odkaz:
http://arxiv.org/abs/0806.1073
Publikováno v:
AIP Conf.Proc.937:349-356,2007
All core collapse supernovae are strongly aspherical. The "Bochum event," with velocity components displaced symmetrically about the principal H$\alpha$ line, strongly suggests that SN 1987A was a bi-polar rather than a uni-polar explosion. While the
Externí odkaz:
http://arxiv.org/abs/0704.3960
Publikováno v:
Prog.Theor.Phys.Suppl.169:196-199,2007
We describe preliminary results of a global model of the radiatively-driven photoionized wind and accretion flow of the high-mass X-ray binary Vela X-1. The full model combines FLASH hydrodynamic calculations, XSTAR photoionization calculations, HULL
Externí odkaz:
http://arxiv.org/abs/0704.0237
Autor:
Wheeler, J. Craig, Akiyama, Shizuka
Publikováno v:
Astrophys.J.654:429-434,2006
The timescale of de-leptonization by neutrino loss and associated contraction of a proto-neutron star is short compared to the time to progagate a shock through the helium core of a massive star, and so the de-leptonization phase does not occur in th
Externí odkaz:
http://arxiv.org/abs/astro-ph/0609717
Autor:
Akiyama, Shizuka, Wheeler, J. Craig
Publikováno v:
Astrophys.J.629:414-421,2005
Traditional models of core collapse suggest the issue of successful versus failed supernova explosions and neutron star versus black hole formation depends monotonically on the mass (and metallicity) of the progenitor star. Here we argue that the iss
Externí odkaz:
http://arxiv.org/abs/astro-ph/0504563
Autor:
Wheeler, J. Craig, Akiyama, Shizuka
Spectropolarimetry of core collapse supernovae has shown that they are asymmetric and often, but not universally, bi-polar. The Type IIb SN1993J and similar events showed large scatter in the Stokes parameter plane. Observational programs clearly hav
Externí odkaz:
http://arxiv.org/abs/astro-ph/0412382
Autor:
Akiyama, Shizuka, Wheeler, J. Craig
A relatively modest value of the initial rotation of the iron core, a period of ~ 6-31 s, will give a very rapidly rotating protoneutron star and hence strong differential rotation with respect to the infalling matter. Under these conditions, a seed
Externí odkaz:
http://arxiv.org/abs/astro-ph/0211458