Search results for "Hypernova"
showing 6 items of 6 documents
Three-dimensional core-collapse supernovae with complex magnetic structures: I. Explosion dynamics
2021
Magnetic fields can play a major role in the dynamics of outstanding explosions associated to violent events such as GRBs and hypernovae, since they provide a natural mechanism to harness the rotational energy of the central proto-neutron star and power relativistic jets through the stellar progenitor. As the structure of such fields is quite uncertain, most numerical models of MHD-driven core-collapse supernovae consider an aligned dipole as initial magnetic field, while the field's morphology can actually be much more complex. We present three-dimensional simulations of core-collapse supernovae with more realistic magnetic structures, such as quadrupolar fields and, for the first time, an…
The chemical signature of jet-driven hypernovae
2020
Hypernovae powered by magnetic jets launched from the surface of rapidly rotating millisecond magnetars are one of the leading models to explain broad-lined Type Ic supernovae (SNe Ic-BL), and have been implicated as an important source of metal enrichment in the early Universe. We investigate the nucleosynthesis in such jet-driven hypernovae using a parameterised, but physically motivated, approach that analytically relates an artificially injected jet energy flux to the power available from the energy in differential rotation in the proto-neutron star. We find ejected $^{56}\mathrm{Ni}$ masses of $0.05\,\mathrm{M}_\odot - 0.45\,\mathrm{M}_\odot$ in our most energetic models with explosion…
Nucleosynthesis in magneto-rotational supernovae
2020
Abstract We present the nucleosynthesis of magneto-rotational supernovae (MR-SNe) including neutrino-driven and magneto-rotational-driven ejecta based, for the first time, on two-dimensional simulations with accurate neutrino transport. The models analysed here have different rotation and magnetic fields, allowing us to explore the impact of these two key ingredients. The accurate neutrino transport of the simulations is critical to analyse the slightly neutron rich and proton rich ejecta that are similar to the, also neutrino-driven, ejecta in standard supernovae. In the model with strong magnetic field, the r-process produces heavy elements up to the third r-process peak (A ∼ 195), in agr…
The X‐ray emission of the supernova remnant W49B: indications of a jet‐like explosion
2007
We report on an XMM-Newton EPIC observation of the galactic supernova remnant W49B, which, on the basis of previous Chandra observations, has been supposed to be the first remnant of a gamma-ray burst discovered in our galaxy. We performed a spatially resolved spectral analysis, which revealed oversolar abundances of Si, S, Ar, Ca, and Fe. Moreover, a high overabundance of Ni is required in the bright central elongated region. Our results support a scenario where the remnant was generated by an asymmetric bipolar explosion where the eastern jet is hotter and more Fe-rich than the western one. An alternative interpretation which associates the X-ray emission with spherically symmetric ejecta…
A physical interpretation of the jet-like X-ray emission from supernova remnant W49B
2007
In the framework of the study of supernova remnants and their complex interaction with the interstellar medium and the circumstellar material, we focus on the galactic supernova remnant W49B. Its morphology exhibits an X-ray bright elongated nebula, terminated on its eastern end by a sharp perpendicular structure aligned with the radio shell. The X-ray spectrum of W49B is characterized by strong K emission lines from Si, S, Ar, Ca, and Fe. There is a variation of the temperature in the remnant with the highest temperature found in the eastern side and the lowest one in the western side. The analysis of the recent observations of W49B indicates that the remnant may be the result of an asymme…
The X-ray emission of the supernova remnant W49B observed withXMM-Newton
2006
In the framework of the study of supernova remnants and their complex interaction with the interstellar medium, we report on an XMM-Newton EPIC observation of the Galactic supernova remnant W49B. We investigate the spatial distribution of the chemical and physical properties of the plasma, so as to get important constraints on the physical scenario, on the dynamics of the supernova explosion, and on the interaction of the supernova remnant with the ambient interstellar clouds. We present line images, equivalent width maps, and a spatially resolved spectral analysis of a set of homogeneous regions. The X-ray spectrum of W49B is characterized by strong K emission lines from Si, S, Ar, Ca and …