Oded Papish - Technion, Israel

Oded Papish
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Name
Oded Papish
Affiliation
Technion, Israel
City
Haifa
Country
Israel

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High Energy Astrophysical Phenomena (11)
 
Solar and Stellar Astrophysics (8)
 
Astrophysics of Galaxies (1)

Publications Authored By Oded Papish

We suggest that the energetic radiation from core-collapse super-energetic supernovae (SESNe) is due to a long lasting accretion process onto the newly born neutron star (NS), resulting from an inefficient operation of the jet-feedback mechanism. The jets that are launched by the accreting NS or black hole (BH) maintain their axis due to a rapidly rotating pre-collapse core, and do not manage to eject core material from near the equatorial plane. The jets are able to eject material from the core along the polar directions, and reduce the gravity near the equatorial plane. Read More

We show that the standing accretion shock instability (SASI) that has been used to ease the shock revival in core collapse supernovae (CCSNe) neutrino-driven explosion models, might play a much more decisive role in supplying the stochastic angular momentum required to trigger an explosion with jittering jets. We find that if the kinetic energy associated with the transverse (non radial) motion of the SASI is larger than about ten percent of the energy associated with the energy of the accreted gas, then the stochastic angular momentum can reach about five percent of the Keplerian specific angular momentum around the newly born neutron star. Such an accretion flow leaves an open conical region along the poles with an average opening angle of about 5 degrees. Read More

Models for supernovae (SNe) arising from thermonuclear explosions of white dwarfs (WDs) have been extensively studied over the last few decades, mostly focusing on the single degenerate (accretion of material of a WD) and double degenerate (WD-WD merger) scenarios. In recent years it was suggested that WD-WD direct collisions provide an additional channel for such explosions. Here we extend the studies of such explosions, and explore the role of Helium-shells in affecting the thermonuclear explosions. Read More

We conduct numerical simulations of the interacting ejecta from an exploding CO white dwarf (WD) with a He WD donor in the double-detonation scenario for Type Ia supernovae (SNe Ia), and study the possibility of exploding the companion WD. We also study the long time imprint of the collision on the supernova remnant. When the donor He WD has a low mass, M_WD = 0. Read More

We use 3D hydrodynamical numerical simulations and show that jittering bipolar jets that power core-collapse supernova (CCSN) explosions channel further accretion onto the newly born neutron star (NS) such that consecutive bipolar jets tend to be launched in the same plane as the first two bipolar jet episodes. In the jittering-jets model the explosion of CCSNe is powered by jittering jets launched by an intermittent accretion disk formed by accreted gas having a stochastic angular momentum. The first two bipolar jets episodes eject mass mainly from the plane defined by the two bipolar axes. Read More

Three-dimensional (3D) simulations in recent years have shown severe difficulties producing 10^51 erg explosions of massive stars with neutrino based mechanisms while on the other hand demonstrated the large potential of mechanical effects, such as winds and jets in driving explosions. In this paper we study the typical time-scale and energy for accelerating gas by neutrinos in core-collapse supernovae (CCSNe) and find that under the most extremely favorable (and probably unrealistic) conditions, the energy of the ejected mass can reach at most 5X10^50 erg. More typical conditions yield explosion energies an order-of-magnitude below the observed 10^51 erg explosions. Read More

We study the properties of jets launched by a neutron star spiralling inside the envelope and core of a red supergiant. We propose that Thorne-Zytkow objects (TZO) are unlikely to be formed via common envelope (CE) evolution if accretion on to the neutron star can exceed the Eddington rate with much of the accretion energy directed into jets that subsequently dissipate within the giant envelope. We use the jet-feedback mechanism, where energy deposited by the jets drives the ejection of the entire envelope and part of the core, and find a very strong interaction of the jets with the core material at late phases of the CE evolution. Read More

We study the flow structure in the jittering-jets explosion model of core-collapse supernovae (CCSNe) using 2.5D hydrodynamical simulations and find that some basic requirements for explosion are met by the flow. In the jittering-jets model jets are launched by intermittent accretion disk around the newly born neutron star and in stochastic directions. Read More

2012Sep
Affiliations: 1Technion, Israel, 2Technion, Israel, 3Technion, Israel, 4Technion, Israel, 5Technion, Israel, 6Technion, Israel, 7Technion, Israel

We study the similarities of jet-medium interactions in several quite different astrophysical systems using 2D and 3D hydrodynamical numerical simulations, and find many similarities. The systems include cooling flow (CF) clusters of galaxies, core-collapse supernovae (CCSNe), planetary nebulae (PNe), and common envelope (CE) evolution. The similarities include hot bubbles inflated by jets in a bipolar structure, vortices on the sides of the jets, vortices inside the inflated bubbles, fragmentation of bubbles to two and more bubbles, and buoyancy of bubbles. Read More

2012Apr
Affiliations: 1Technion, Israel, 2Technion, Israel

We perform hydrodynamical simulations of core collapse supernovae (CCSNe) with a cylindrically-symmetrical numerical code (FLASH) to study the inflation of bubbles and the initiation of the explosion within the frame of the jittering-jets model. We study the typical time- scale of the model and compare it to the typical time-scale of the delayed neutrino mechanism. Our analysis shows that the explosion energy of the delayed neutrino mechanism is an order of magnitude less than the required 10^51 erg. Read More

We calculate the nucleosynthesis inside the hot bubble formed in the jittering-jets model for core collapse supernovae (CCSNe) explosions, and find the formation of several times 10^-4 M_\odot of r-process elements. In the jittering-jets model fast jets launched from a stochastic accretion disk around the newly formed neutron star are shocked at several thousands km, and form hot high-pressure bubbles. These bubbles merge to form a large bubble that explode the star. Read More

We argue that jittering jets, i.e., jets that have their launching direction rapidly change, launched by the newly formed neutron star in a core collapse supernova can explode the star. Read More