The recent Fermi observation of GRB 080916C shows that the bright photosphere emission associated with a putative fireball is missing, which suggests Poynting-flux-dominated outflow. We propose model gamma-ray burst (GRB) prompt in regime, namely, Internal-Collision-induced MAgnetic Reconnection and Turbulence (ICMART) model. It envisaged central engine launches an intermittent, magnetically-dominated wind, region, ejecta still moderately magnetized. Similar to internal shock (IS) model,...

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for substantial revisions our cosmic ray transport. We use recently obtained scalings MHD modes to calculate the scattering frequency rays. consider gyroresonance with (Alfvénic, slow, and fast) transit-time damping by fast modes. conclude that is dominant contribution typical interstellar conditions. In contrast earlier studies, we find Alfvénic slow are inefficient because they far from isotropy usually assumed.

We consider the propagation of cosmic rays in turbulent magnetic fields. use models magnetohydrodynamic turbulence that were tested numerical simulations, which is injected on large scale and cascades to small scales. Our attention focused strong turbulence, but we also briefly discuss effects weak slab Alfvénic perturbations can have. The latter are likely emerge as a result instabilities with ray fluid itself, e.g., beaming gyroresonance rays. To describe interaction develop non-linear...

Diffusion of cosmic rays (CRs) is the key process for understanding their propagation and acceleration. We employ description spatial separation magnetic field lines in magnetohydrodynamic turbulence Lazarian & Vishniac to quantify divergence on scales less than injection scale show that this induces superdiffusion CR direction perpendicular mean field. The displacement squared increases, not as distance x along field, which case a regular diffusion, but x3 freely streaming CRs. dependence...

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions the picture cosmic-ray transport. In this paper we use recently obtained scaling laws MHD modes to obtain scattering frequency cosmic rays. Using quasi-linear theory, calculate gyroresonance with (Alfvénic, slow, and fast) transit-time damping (TTD) by fast modes. We provide calculations various phases interstellar medium realistic driving that is consistent velocity dispersions observed diffuse gas....

We calculate the relative grain-grain motions arising from interstellar magnetohydrodynamic (MHD) turbulence. The MHD turbulence includes both fluid and magnetic fluctuations. While accelerate grains through hydro-drag, electromagnetic fluctuations resonant interactions. consider incompressive (Alfvén) compressive (fast slow) modes use descriptions of obtained in Cho & Lazarian (2002). Calculations grain motion are made for realistic charging that is consistent with velocity dispersions...

We investigate shattering and coagulation of dust grains in turbulent interstellar medium (ISM). The typical velocity grain as a function size has been calculated for various ISM phases based on theory dynamics compressible magnetohydrodynamic turbulence. In this paper, we develop scheme apply it to by using the velocities predicted above turbulence theory. Since large tend acquire dispersions shown earlier studies, be shattered. Large effects are indeed seen warm ionized (WIM) within few...

Although many high-energy neutrinos detected by the IceCube telescope are believed to have an extraterrestrial origin, their astrophysical sources remain a mystery. Recently, unprecedented discovery of muon neutrino event coincident with multiwavelength flare from blazar, TXS $0506+056$, shed some light on origin neutrinos. It is usually that blazar produced relativistic jet launched accreting supermassive black hole (SMBH). Here, we show can be interpreted inelastic hadronuclear...

In this Letter, we propose that the x-ray and TeV observations in vicinity of Geminga can be understood framework anisotropic diffusion injected electrons or positrons. This interpretation only requires turbulence to sub-Alfv\'enic with local mean magnetic field direction approximately aligned our line sight towards Geminga, without invoking extreme conditions for environment, such as an extremely small coefficient a weak submicrogauss suggested previous literature.

Abstract Plasma turbulence is a ubiquitous dynamical process that transfers energy across many spatial and temporal scales affects energetic particle transport. Recent advances in the understanding of compressible magnetohydrodynamic (MHD) demonstrate important role damping shaping distributions on small scales, yet its observational evidence still lacking. This study provides first substantial collisionless (CD) modulation small-amplitude MHD cascade Earth’s magnetosheath using four Cluster...

We discuss the damping of strong magnetic turbulence downstream forward shock young supernova remnants (SNRs). find that fields have been produced by streaming instability in upstream region or other kinetic instabilities at may be efficiently damped, so enhanced field strength would typically a thickness order ld = 1016-1017?cm. The nonthermal X-ray filaments observed SNRs are thus possibly limited and not energy losses radiating electrons. Therefore, measure strength, claims efficient...

We study diffusion of Cosmic Rays (CRs) in turbulent magnetic fields using test particle simulations. Electromagnetic are produced direct numerical MHD simulations turbulence and used as an input for tracing, feedback on being ignored. Statistical transport coefficients from the runs compared with earlier analytical predictions. find qualitative correspondence between them various aspects CR diffusion. In incompressible case, that we consider this paper, dominant scattering mechanism occurs...

We study properties of magnetohydrodynamic (MHD) eigenmodes by decomposing the data MHD simulations into linear modes - namely Alfven, slow magnetosonic, and fast magnetosonic modes. drive turbulence with a mixture solenoidal compressive driving, while varying Alfven Mach number (MA), plasma beta, sonic from sub-sonic to trans-sonic. find that proportion in mode increases increasing forcing. This can also become dominant fraction mixture. The anisotropy is analyzed means their structure...

Abstract Plasma turbulence is a ubiquitous dynamical process that transfers energy across many spatial and temporal scales in astrophysical space plasma systems. Although the theory of anisotropic magnetohydrodynamic (MHD) has successfully described natural phenomena, its core prediction an Alfvénic transition from weak to strong MHD when cascades large small not been observationally confirmed. Here we report evidence for weak-to-strong small-amplitude, turbulent fluctuations Earth’s...

Centromeres in eukaryotic species are defined by the presence of a centromere-specific histone H3 variant, CENH3. CENH3 plays key role recruiting other centromeric proteins; thus, it is central component kinetochore formation and centromere function. The proteins several plant animal were found to be under positive selection, which was hypothesized respond rapid changing repetitive DNA sequences associated with centromeres. Here, we report expression evolution CenH3 genes two allotetraploid...

High-energy gamma-ray emission has been detected recently from supernova remnants (SNRs) and their surroundings. The existence of molecular clouds near some the SNRs suggests that gamma rays originate predominantly p–p interactions with cosmic (CRs) accelerated at a closeby SNR shock wave. Here we investigate acceleration CRs production in cloud self-consistently by taking into account streaming instability background turbulence both front ensuing propagation to clouds. We focus on later...

ABSTRACT We study the damping processes of both incompressible and compressible magnetohydrodynamic (MHD) turbulence in a partially ionized medium. start from linear analysis MHD waves, applying single-fluid two-fluid treatments. The rates derived are then used determining scales turbulence. physical connection between scale cutoff boundary waves is investigated. find two branches slow modes propagating ions neutrals, respectively, below turbulence, offer thorough discussion their...

We discuss a new mechanism of dust acceleration that acts in turbulent magnetized medium. The magnetohydrodynamic (MHD) turbulence includes both fluid motions and magnetic fluctuations. show while the bring about grain through drag, electromagnetic fluctuations can accelerate grains resonant interactions. In this Letter, we calculate by gyroresonance cold neutral consider incompressible compressible MHD modes. fast modes dominate acceleration. For parameters chosen, render to supersonic...

A correct description of cosmic-ray (CR) diffusion in turbulent plasma is essential for many astrophysical and heliospheric problems. This paper aims to present physical behavior CRs actual magnetic fields, model which has been numerically tested. We perform test particle simulations compressible magnetohydrodynamic turbulence. obtain scattering spatial coefficients by tracing trajectories. find no resonance gap pitch-angle at 90$^\circ$. Our result confirms the dominance mirror interaction...

We revisit propagation of galactic cosmic rays (CRs) in light recent advances CR diffusion theory realistic interstellar turbulence. use a tested model turbulence which it has been shown that fast modes dominate scattering CRs. As result, becomes inhomogeneous and environment dependent. By adopting the formalism nonlinear developed by Yan & Lazarian, we calculate CRs self-consistently from first principles. assume two- phase for Galaxy to account different damping mechanisms modes, find...

Abstract This paper studies cosmic-ray (CR) transport in magnetohydrodynamic (MHD) turbulence. CR is strongly dependent on the properties of magnetic We perform test particle simulations to study interactions with both total MHD turbulence and decomposed modes. The spatial diffusion coefficients pitch angle scattering are calculated from trajectories Our results confirm that fast modes dominate propagation, whereas Alfvén slow much less efficient have shown similar pitch-angle rates....

Alfven wave is the single most important physical phenomenon of magneto-hydrodynamic turbulence and has far-reaching impact to almost all studies related astrophysical magnetic field. Yet restoration fluctuations from a given field, aka local problem, never properly addressed in literature albeit its importance. Previous works model fluctuation as perturbation along straight-line, constant However, Lazarian & Pogosyan (2012) suggested that decomposition straight line, aka. global frame...

The interstellar medium is turbulent, and this induces relative motions of dust grains. We calculate velocities charged grains in a partially ionized magnetized gas. account for the anisotropy magnetohydrodynamic (MHD) turbulence, grain coupling with magnetic field, turbulence cutoff arising from ambipolar drag. obtain parameters consistent those H I dark clouds. These are smaller than earlier papers, which MHD effects were disregarded. Finally, we consider photoelectric emission, radiation...

We study the requirement on jet power in conventional p-$\gamma$ models (photopion production and Bethe-Heitler pair production) for TeV BL Lac objects. select a sample of objects whose SEDs are difficult to be explained by one-zone leptonic model. Based relation between interaction efficiency opacity $\gamma\gamma$ absorption, we find that detection emission poses upper limits efficiencies these sources hence minimum powers can derived accordingly. obtained exceed Eddington luminosity...