Three Dimensional Evolution of SN 1987A in a Self-Gravitating Disk

The introduction of an exponential or power law gradient in the interstellar medium (ISM) allows to produce an asymmetric evolution of the supernova remnant (SNR) when the framework of the thin layer approximation is adopted. Unfortunately both the exponential and power law gradients for the ISM do not have a well defined physical meaning. The physics conversely is well represented by an isothermal self-gravitating disk of particles whose velocity is everywhere Maxwellian. We derived a law of motion in the framework of the thin layer approximation with a control parameter of the swept mass. The photon’s losses, which are often neglected in the thin layer approximation, are modeled trough velocity dependence. The developed framework is applied to SNR 1987A and the three observed rings are simulated.

The Relativistic Three-Dimensional Evolution of SN 1987A

The high velocities observed in supernovae require a relativistic treatment for the equation of motion in the presence of gradients in the density of the interstellar medium. The adopted theory is that of the thin layer approximation. The chosen medium is auto-gravitating with respect to an equatorial plane. The differential equation which governs the relativistic conservation of momentum is solved numerically and by recursion. The asymmetric field of relativistic velocities as well the time dilation is plotted at the age of 1 yr for SN 1987A.

Study the Radial Expansion of SN 1987A Using Counting Pixels Method

Physical properties of supernova 1987A were investigated including: Expansion velocity;Current mass;Radius;Temperature and the Rate of the expansion by applying Counting Pixels Method (CPM) in comparison with the application of the Povida and Self-Similar Solution theoretical models which in forced the idea for adopting such a model to be applied for supernova type II. Then tow results are found to be in a good agreement with the Self-Similar solution model rather than that of Povida model. The high density of the region that surrounded the exploding system acting as decelerating parameter and down the expansion velocity of the supernova from 3900 km·s-1 to 1200 km·s-1 during the past 23 years from the explosion, with a current size equal 0.39 pc, and with an expansion rate of 0.41 per a year.

Supernova 1987A's Keyhole:A Long-lived Jet-pair in the Final Explosion Phase of Core-collapse Supernovae

I further study the manner by which a pair of opposite jets shape the“keyhole”morphological structure of the core-collapse supernova(CCSN)SN 1997A,now the CCSN remnant(CCSNR)1987A.By doing so,I strengthen the claim that the jittering-jet explosion mechanism accounts for most,likely all,CCSNe.The“keyhole”structure comprises a northern low-intensity zone closed with a bright rim on its front and an elongated low-intensity nozzle in the south.This rim-nozzle asymmetry is observed in some cooling flow clusters and planetary nebulae that are observed to be shaped by jets.I build a toy model that uses the planar jittering jets pattern,where consecutive pairs of jets tend to jitter in a common plane,implying that the accreted gas onto the newly born neutron star at the late explosion phase flows perpendicular to that plane.This allows for a long-lived jet-launching episode.This long-lasting jet-launching episode launches more mass into the jets that can inflate larger pairs of ears or bubbles,forming the main jets'axis of the CCSNR that is not necessarily related to a possible pre-collapse core rotation.I discuss the relation of the main jets'axis to the neutron star's natal kick velocity.

Supernova neutrinos in a strangeon star model

The neutrino burst detected during supernova SN 1987A is explained in a strangeon star model, in which it is proposed that a pulsar-like compact object is composed of strangeons （strangeon： an abbreviation for ＂strange nucleon＂）. A nascent strangeon star＇s initial internal energy is calculated, with the inclusion of pion excitation （energy around 1053 erg, comparable to the gravitational binding energy of a collapsed core）. A liquid-solid phase transition at temperature - 1 - 2 MeV may occur only a few tens of seconds after core collapse, and the thermal evolution of a strangeon star is then modeled. It is found that the neutrino burst observed from SN 1987A can be reproduced in such a cooling model.

Energy Conservation in the Thin Layer Approximation: III. The Spherical Relativistic Case for Supernovae

The theory of the conservation of energy in the thin layer approximation has been extended to special relativity. Four models for the density of the circumstellar medium are analyzed, which are represented by constant, power law, exponential and Emden (n = 5) profile for density. The astrophysical results are presented in a numerical way, except for a Taylor expansion of the four trajectories in the surrounding of the origin. The free parameters of the models are particularized for SN1993j, for which the radius versus time is known. Some evaluations on the time dilation are presented.

Relativistic Motion with Viscosity: II Stokes’s Law of Resistance

The deduction of a relativistic and mildly relativistic equation of motion in the presence of a drag force proportional to the velocity is presented. The obtained results are used to model the trajectory of the supernova SN1993J and the light curves of gamma-ray bursts.

PadéApproximant for the Equation of Motion of a Supernova Remnant

In this paper we derive three equations of motion for a supernova remnant (SNR) in the framework of the thin layer approximation using the Padé approximant. The circumstellar medium is assumed to follow a density profile of either an exponential type, a Gaussian type, or a Lane-Emden (n = 5) type. The three equations of motion are applied to four SNRs: Tycho, Cas A, Cygnus loop, and SN 1006. The percentage error of the Padé approximated solution is always less than 10%. The theoretical decrease of the velocity over ten years for SNRs is evaluated.

Energy Conservation in the Thin Layer Approximation: II. The Asymmetric Classic Case for Supernovae Remnant

Here we extend the conservation of energy in the framework of the thin layer approximation to the asymmetrical case. Four types of interstellar mediums are analysed, in which the density follows an inverse square profile, a power law profile, an exponential profile and a toroidal profile. An analytical solution for the radius as a function of time and the polar angle in spherical coordinates is derived in the case of the inverse square profile. The analytical and numerical results are applied to two supernova remnants: SN 1987A and SN 1006. The back reaction due to the radiative losses is evaluated in the case of the inverse square profile for the surrounding medium. Two models for the image formation are presented, which explain the triple ring visible in SN 1987A and the jet feature of SN 1006.