We here discuss a new model of $\ensuremath{\gamma}$-ray bursts (GRBs) based on differentially rotating strange stars. Strange stars in this and neutron the Klu\ifmmode \acute{z}\else \'{z}\fi{}niak-Ruderman can produce extremely relativistic, variable fireballs required by GRBs then become millisecond pulsars. The effect such pulsars expansion postburst through magnetic dipole radiation is studied. show that these two models explain naturally not only various features but also light curves...

Whether gamma-ray bursts are highly beamed or not is a very difficult but important problem that we confronted with. Some theorists suggest beaming effect usually leads to sharp break in the afterglow light curve during ultrarelativistic phase, with breaking point determined by γ = 1/θ0, where Lorentz factor of blast wave and θ0 initial half-opening angle ejecta, numerical studies tend reject suggestion. We note previous uniformly based on dynamics proper for nonrelativistic waves. Here...

Mobile edge computing (MEC), which enables delay-sensitive tasks to be executed at network edges, has been proposed accommodate the explosive growth of Internet Things. However, growing demands for massive connectivity, ultra-low latency, and high reliability in various emerging resource-hungry computation-intensive applications pose new challenges access capacity. This motivates us conceive a MEC framework from an air-ground integration perspective. First, we present review state-of-the-art...

The heat–electricity integrated energy system (HE-IES) with hubs (EHs) and prosumers is the typical form of future systems. An EH can efficiently model integration different carriers coordinate an sharing multiple in HE-IES. In this article, a closed-loop framework designed to integrate contract theory consensus algorithms for bilevel system. First, scheme between lower level formulated. Contract utilized maximize profits under information asymmetry scenario, items are electric thermal...

The afterglow of a gamma-ray burst (GRB) is commonly thought to be the result continuous deceleration relativistically expanding fireball in surrounding medium. Assuming that expansion adiabatic and density medium power-law function shock radius, i.e. next ∝ R−k, we study effects first-order radiative correction non-uniformity on GRB analytically. We first derive new relation among observed time, radius Lorentz factor fireball: t⊕ = R/4(4−k) γ2c, also comoving tco 2R/(5−k) γc. evolution by...

The conventional generic model is deemed to explain the dynamics of $γ$-ray burst remnants very well, no matter whether they are adiabatic or highly radiative. However, we find that for expansion, could not reproduce Sedov solution in non-relativistic phase, thus needs be revised. In present paper, a new differential equation derived. based on this has been shown correct both radiative and fireballs, ultra-relativistic phase.

Energy consumption represents a significant cost in data center operation. A large fraction of the energy, however, is used to power idle servers when workload low. Dynamic provisioning techniques aim at saving this portion by turning off unnecessary servers. In paper, we explore how much gain knowing future information can bring dynamic provisioning. particular, develop online solutions with and without available. We first reveal an elegant structure offline problem, which allows us...

It is believed that orphan afterglow searches can help to measure the beaming angle in gamma-ray bursts (GRBs). Great expectations have been put on this method. We point out method fact not as simple we originally expected. As a result of baryon-rich environment common almost all popular progenitor models, there should be many failed bursts, i.e. fireballs with Lorentz factor much less than 100–1000, but still larger unity. In fact, number may even successful bursts. Owing existence these...

We numerically investigate optical afterglows from two-component jets under various configurations. Generally, the light curve is characterized by a rapid rebrightening when observer off-axis with respect to narrow component, amplitude and peak time depending on detailed parameters. further show that afterglow of XRF 030723, especially its notable rebrightening, can be well explained typical jet. This X-ray flash, together GRB 030329, strongly hints toward jet model as unified picture for...

Recent observations show that the temporal decay of R-band afterglow from GRB 990123 steepened about 2.5 days after burst. We here propose a possible explanation for such steepening: shock expanding in dense medium has undergone transition relativistic phase to nonrelativistic phase. find this model is consistent with if density 3 × 106 cm-3. By fitting our observed optical and X-ray quantitatively, we further infer electron magnetic energy fractions shocked two parameters are 0.1 2 10-8,...

The interaction of a relativistic fireball with its ambient medium is described through two shocks: reverse shock that propagates into the fireball, and forward medium. observed optical flash GRB 990123 has been considered to be emission from such shock. observational properties afterglows suggest progenitors some GRBs may massive stars their surrounding media stellar winds. We here study very early shocks in An mainly arises while radio flare produced by peak flux densities flashes are...

The optical flash accompanying GRB 990123 is believed to be powered by the reverse shock of a thin shell. With best fitted physical parameters for (Panaitescu & Kumar 2001) and assumption that in are same as those afterglow, we show that: 1) shell thick but not thin, have provided light curve case which coincides with observation; 2) theoretical peak flux accounts only 3\times10^{-4} observed. In order compensate this divergency, electron energy ration magnetic ratio $\epsilon_e$,...

view Abstract Citations (91) References (49) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Conversion of Two-Flavor to Three-Flavor Quark Matter in a Supernova Core Dai, Zigao ; Peng, Qiuhe Lu, Tan physical process that nuclear matter turns into strange quark supernova core, studied by Gentile et al. (1993), is very likely consist two distinguishable processes. first phase transition between and two-flavor matter. second, which have been investigated...

Due to some refinements in the dynamics, we can follow overall evolution of a realistic jet numerically till its bulk velocity being as small $\beta c \sim 10^{-3} c$. We find no obvious break optical light curve during relativistic phase itself. However, an does exist at transition from non-relativistic phase, which typically occurs time $t 10^6$ --- $10^{6.5}$ s (i.e., 10 30 d). The is affected by many parameters, such electron energy fraction $\xi_{\rm e}$, magnetic B}^2$, initial half...

We investigate in detail some popular cosmological models light of the latest observational data, including Union2.1 supernovae compilation, baryon acoustic oscillation measurements from WiggleZ Dark Energy Survey, cosmic microwave background information WMAP 7-year observations along with Hubble parameter data. Based on model selection statistics such as Akaike and Bayesian criterias, we compare different to assess worth them. do not assume a flat universe fitting. Our results show that...

Energy deficiency and carbon emission are two increasingly grave issues recently. Internet (EI), as a promising solution, has received extensive attentions globally. Among numerous key technologies practice of EI, vehicle to grid (V2G) provides feasible solution reduce the level demand-supply mismatch by leveraging bidirectional energy-trading capabilities electric vehicles (EVs). In this paper, we propose secure efficient V2G energy trading framework exploring blockchain edge computing....

In an integrated energy distribution system (IEDS), hub has been introduced and deemed to be a suitable tool for managing integrating multi-party forms. Due different energies having diverse characteristics being coupled with each other, it is difficult implement the optimal scheduling of multiple sources. Therefore, optimization management model proposed based on Stackelberg game, which considers exergy conversion sources in operation modes. The problem solved by two-layer distributed...

We analyze in detail the hydrodynamics and afterglow emission of an ultrarelativistic blast wave when it expands a density-jump medium. Such medium is likely to appear vicinity gamma-ray bursts (GRBs) associated with massive stars. The interaction this described through reverse shock forward shock. show that initially relativistic if factor density jump (α) much larger than 21 Newtonian 1 < α ≪ 21. also calculate light curves during find optical flux decays abruptly, then rises rapidly,...

A gamma-ray burst (GRB) afterglow has been commonly thought to be due continuous deceleration of a postburst fireball. Many analytical models have made simplifications for dynamics the fireball and its radiation property, although they are successful at explaining overall features observed afterglows. We here propose model GRB in which evolution is an intermediate case between adiabatic highly radiative expansion. In our model, both contribution electrons behind external blast wave...

The unusual hard x-ray burster GRO J1744-28 recently discovered by the Compton Gamma-Ray Observatory can be modeled as a strange star with dipolar magnetic field of </=10(11) gauss. According to this model, when accreted mass exceeds some critical mass, its crust breaks, resulting in conversion matter into and release energy. Subsequently, fireball forms expands relativistically outward. expanding interacts surrounding interstellar medium, causing kinetic energy radiated shock waves...

Currently popular models for progenitors of gamma-ray bursts (GRBs) are the mergers compact objects and explosions massive stars. These two cases have distinctive environments GRBs: object occur in interstellar medium (ISM) stars preburst stellar wind. We here discuss neutrino afterglows from reverse shocks as a result interaction relativistic fireballs with their surrounding wind matter. After comparing analytical Waxman & Bahcall homogeneous ISM case, we find that differential spectrum...

We calculate the spectra of inverse Compton (IC) emissions in gamma-ray burst (GRB) shocks produced when relativistic ejecta encounters external interstellar medium, assuming a broken power-law approximation to synchrotron seed spectrum. Four IC processes, including self-Compton (SSC) processes GRB forward and reverse shocks, two combined-IC (i.e., scattering shock photons on electrons shocks), are considered. find that SSC emission from dominates over other energy bands tens MeV GeV, for...

A new parameterization for the dark energy equation of state(EoS) is proposed and some its cosmological consequences are also investigated. This modification Efstathiou' EoS parameterization. $w (z)$ a well behaved function $z\gg1$ has same behavior in $z$ at low redshifts with In this there two free parameter $w_0$ $w_a$. We discuss constraints on model's parameters from current observational data. The best fit values $1\sigma$ confidence-level regions are:...