st ro - p h / 02 07 41 9 v 2 2 1 A ug 2 00 2 Rarefaction Shocks , Shock Errors and Low Order of Accuracy in ZEUS

ar X iv : a st ro - p h / 02 07 41 9 v 1 1 9 Ju l 2 00 2 Rarefaction Shocks , Shock Errors and Low Order of Accuracy in ZEUS

ar X iv : a st ro - p h / 02 08 14 8 v 1 7 A ug 2 00 2 On the Ejection Mechanism of Bullets in SS 433

We discuss plausible mechanisms to produce bullet-like ejecta from the precessing disk in the SS 433 system. We show that non-steady shocks in the subKeplerian accretion flow can provide the basic timescale of the ejection interval while the magnetic rubber-band effect of the toroidal flux tubes in this disk can yield flaring events. Subject headings: accretion, accretion disks — hydrodynamics ...

ar X iv : a st ro - p h / 02 05 14 4 v 1 9 M ay 2 00 2 X - ray Rich GRB , Photospheres and Variability

We investigate the relationship between the quasi-thermal baryon-related photosphere in relativistic outflows, and the internal shocks arising outside them, which out to a limiting radius may be able to create enough pairs to extend the optically thick region. Variable gamma-ray light curves are likely to arise outside this limiting pair-forming shock radius, while X-ray excess bursts may arise...

ar X iv : a st ro - p h / 04 10 37 7 v 1 1 5 O ct 2 00 4 Hydrodynamics of Internal Shocks in Relativistic Outflows

We study the hydrodynamical effects of two colliding shells, adopted to model internal shocks in various relativistic outflows such as gamma-ray bursts and blazars. We find that the density profiles are significantly affected by the propagation of rarefaction waves. A split-feature appears at the contact discontinuity of the two shells. The shell spreading with a few ten percent of the speed of...

ar X iv : a st ro - p h / 05 02 23 2 v 1 11 F eb 2 00 5 Supernova neutrino challenges

A principal ‘supernova neutrino challenge’ is the computational difficulty of six-dimensional neutrino radiation hydrodynamics. The variety of resulting approximations has provoked a long history of uncertainty in the core-collapse supernova explosion mechanism, but recent work highlighting low-mode convection and a newlyrecognized instability in spherical accretion shocks may signal (yet anoth...