We apply a synchro-curvature spectral emission model based on characterizing the dynamics of magnetospheric particles to fit the phase-average spectra of the most extended database for the non-thermal spectra of pulsars. We consider 36 pulsars with well-determined non-thermal spectra from X-rays to gamma-rays. The sample includes Crab and Crab twin, for which the spectra extends even to the optical/ultraviolet and infrared energies. We find that the model --with just three physical parameters and a global scaling-- can fit the observations well across eight orders of magnitude for 18 of the 36 pulsars studied. Additionally, we find a set of 8 pulsars for which the model still provides arguably good fits and another set of 10 pulsars for which the model fails in reproducing the spectra. We discuss why, propose and provide physical interpretations for a simple model extension (related to the geometry of the accelerating system with regards to the observer) that allows dealing with all such cases, ultimately providing very good fits for all pulsars. The extended model is still austere, adding only two additional parameters to the former set, of the same kind of the ones previously used. We use these fits to discuss issues going from the observed spectral origin, to the extent of the dominance of synchrotron or curvature regimes, the use of a model as predictor for searching new non-thermal pulsars starting from gamma-ray surveys, and how the model offers a setting where phase shifts between X-ray and gamma-ray light curves would naturally arise.
In recent years, surprise discoveries of pulsed emission from the Crab and Vela pulsars above 100 GeV have drawn renewed attention to this largely unexplored region of the energy range. In this paper, we discuss example light curves due to curvature emission, with good resolution in the different energy bands. Continued light curve modelling may help to discriminate between different emission mechanisms, as well as constrain the location where emission is produced within the pulsar magnetosphere, including regions beyond the light cylinder.
A spatially-independent model that can be used to calculate the temporal evolution of the electron/ positron spectrum in a spherically expanding pulsar wind nebula is presented. The model is applied to the young nebula G21.5-0.9, as well as to the unidentified TeV sources HESS J1427-608 and HESS J1507-622. The parameters derived from the model strengthens the idea that the unidentified sources can be identified as evolved pulsar wind nebulae.
In this paper we study the generation of high energy emission from normal pulsars. For this purpose we consider the particles accelerated in the outer magnetosphere sliding along the closed magnetic field lines. It has been shown that in due course of motion the initial small pitch angle increases and at a certain distance from the neutron star the synchrotron emission becomes significant. We found that a region covered from $150$ to $500$ stellar radii the emission pattern is characterised by energies in the interval $(0.1-10)$ MeV.
We investigate the strong electric current sheet that develops at the tip of the pulsar closed line region through time dependent three-dimensional numerical simulations of a rotating magnetic dipole. We show that curvature radiation from relativistic electrons and positrons in the current sheet may naturally account for several features of the high-energy pulsar emission. We obtain light curves and polarization profiles for the complete range of magnetic field inclination angles and observer orientations, and compare our results to recent observations from the Fermi gamma-ray telescope.
Interpretation of the recently discovered very high energy (VHE) pulsed emission from the Crab pulsar is presented. By taking into account the fact that Crab pulsar's radiation for the optical and VHE spectrum peak at the same phases, we argue that the source of this broad band emission is spatially localized. It is shown that the only mechanism providing the results of the MAGIC Cherenkov telescope, should be the synchrotron radiation. We find that in the magnetospheric electron-positron plasma, due to the cyclotron instability, the pitch angle becomes non-vanishing, which leads to the effici…
The Fermi Large Area Telescope, in collaboration with several groups from the radio community, have had marvellous success at uncovering new gamma-ray millisecond pulsars (MSPs). In fact, MSPs now make up a sizable fraction of the total number of known gamma-ray pulsars. The MSP population is characterized by a variety of pulse profile shapes, peak separations, and radio-to-gamma phase lags, with some members exhibiting nearly phase-aligned radio and gamma-ray light curves (LCs). The MSPs' short spin periods underline the importance of including special relativistic effects in LC calculations,…
We present the results of modelling of the radio spectrum evolution and dispersion measure variations of PSR B1259-63, a pulsar in a binary system with Be star LS 2883. We base our model on a hypothesis that the observed variations of the spectrum are caused by thermal free-free absorption occurring in the pulsar surroundings. We reproduce the observed pulsar spectral shapes in order to examine the influence of the stellar wind of LS 2883 and the equatorial disc on the pulsar's radiation. The simulations of the pulsar's radio emission and its consequent free-free absorption give us an insight …
Results of a simulation of synchrotron-self Compton (SSC) emission from a rotation-powered pulsar are presented. The radiating particles are assumed to be both accelerated primary electrons and a spectrum of electron-positron pairs produced in cascades near the polar cap. They follow trajectories in a slot gap using 3D force-free magnetic field geometry, gaining pitch angles through resonant cyclotron absorption of radio photons, radiating and scattering synchrotron emission at high altitudes out to and beyond the light cylinder. Full angular dependence of the synchrotron photon density is sim…
For Crab-like pulsars we consider the synchrotron mechanism influenced by relativistic effects of rotation to study the production of the very high energy (VHE) pulsed radiation. The process of quasi-linear diffusion (QLD) is applied to prevent the damping of the synchrotron emission due to extremely strong magnetic field. By examining the kinetic equation governing the QLD, apart from the synchrotron radiative force, we taken into account the the so-called reaction force, that is responsible for corotation and influences plasma processes in the nearby zone of the light cylinder (LC) surface. …
The period and the period derivative of a pulsar are critical magnitudes for defining the properties of the magnetospheric size and plasma dynamics. The pulsar light cylinder, the magnetic field intensity nearby it, and the curvature radius all depend on these timing properties, and shape the observed high-energy synchro-curvature emission. Therefore, the radiative properties of pulsars are inextricably linked to them. This fact poses the question of how well does a given pulsar's spectral energy distribution embeds information of the timing parameters, and if so, whether we can deduce them if…
The detected high-energy pulsars' population is growing in number, and thus, having agile and physically relevant codes to analyze it consistently is important. Here, we update our existing synchro-curvature radiation model by including a better treatment of the particle injection, particularly where the large pitch angle particles dominate the spectra, and by implementing a fast and accurate minimization technique. The latter allows a large improvement in computational cost, needed to test model enhancements and to apply the model to a larger pulsar population. We successfully fit the sample …
We study the synchrotron radiation as the observed non-thermal X-ray emission from old pulsars ($\gtrsim1-10$Myr) to investigate the particle acceleration in their magnetospheres. We assume that the power-law component of the observed X-ray spectra is caused by the synchrotron radiation from electrons and positrons in the magnetosphere. We consider two pair production mechanisms of X-ray emitting particles, the magnetic and the photon-photon pair productions. High-energy photons, which ignite the pair production, are emitted via the curvature radiation of the accelerated particles. We use the …
In the last decade, the relativistic magnetohydrodynamic (MHD) modelling of pulsar wind nebulae, and of the Crab nebula in particular, has been highly successful, with many of the observed dynamical and emission properties reproduced down to the finest detail. Here, we critically discuss the results of some of the most recent studies: namely the investigation of the origin of the radio emitting particles and the quest for the acceleration sites of particles of different energies along the termination shock, by using wisps motion as a diagnostic tool; the study of the magnetic dissipation proce…
The Fermi Large Area Telescope (LAT) has recently reported the detection of pulsed gamma-rays from 6 young pulsars (J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850, and J1718-3825), all exhibiting single-peaked pulse profiles (Weltevrede et al., 2010). High-quality radio polarization data are also available for 5 of these pulsars, allowing derivation of constraints on their viewing geometries. We obtain independent constraints on the viewing geometries of these pulsars by using a geometric pulsar emission code to model the Fermi LAT and radio light curves. We find fits for the magne…
Pulsars emit low-frequency radio waves through to high-energy gamma-rays that are generated anywhere from the surface out to the edges of the magnetosphere. Detecting correlated mode changes in the multi-wavelength emission is therefore key to understanding the physical relationship between these emission sites. Through simultaneous observations, we have detected synchronous switching in the radio and X-ray emission properties of PSR B0943+10. When the pulsar is in a sustained radio 'bright' mode, the X-rays show only an un-pulsed, non-thermal component. Conversely, when the pulsar is in a rad…
We modelled the radio and gamma-ray light curves of millisecond pulsars using outer gap, two-pole caustic, low-altitude slot gap, and pair-starved polar cap geometric models, combined with a semi-empirical conal radio model. We find that no model fits all cases, with the outer gap and two-pole caustic models providing best fits for comparable numbers of millisecond pulsar light curves. We find a broad distribution of best-fit inclination angles as well as a clustering at large observer angles. The outer gap model furthermore seems to require relatively larger inclination angles, while the two-…
Guillemot et al. recently reported the discovery of $γ$-ray pulsations from the 22.7ms pulsar (pulsar A) in the famous double pulsar system J0737-3039A/B. The $γ$-ray light curve (LC) of pulsar A has two peaks separated by approximately half a rotation, and these are non-coincident with the observed radio and X-ray peaks. This suggests that the $γ$-ray emission originates in a part of the magnetosphere distinct from where the radio and X-ray radiation is generated. Thus far, three different methods have been applied to constrain the viewing geometry of pulsar A (its inclination and observer an…
We present a numerical study of the properties of the flow produced by the collision of a magnetized anisotropic pulsar wind with the circumbinary environment. We focus on studying the impact of the high wind magnetization on the geometrical structure of the shocked flow. This work is an extension of our earlier studies that focused on a purely hydrodynamic interaction and weak wind magnetization. We consider the collision in the axisymmetric approximation, that is, the pulsar rotation axis is assumed to be oriented along the line between the pulsar and the optical star. The increase of the ma…
Electrons/positrons produced in a pulsar magnetosphere emit synchrotron radiation, which is widely believed as the origin of the non-thermal X-ray emission detected from pulsars. Particles are produced by curvature photons emitted from accelerated particles in the magnetosphere. These curvature photons are detected as pulsed $γ$-ray emissions from pulsars with age $\lesssim10^6$ yr. Using $γ$-ray observations and analytical model, we impose severe constraints on the synchrotron radiation as a mechanism of the non-thermal X-ray emission. In most middle-aged pulsars ($\sim10^5-10^6$ yr) which ph…
In this paper, we present a numerical study of the properties of the flow produced by the collision of a magnetized anisotropic pulsar wind with its environment in binary system. We compare the impact of both the magnetic field and the wind anisotropy to the benchmark case of a purely hydrodynamical (HD) interaction of isotropic winds, which has been studied in detail by Bogovalov et al. (2008). We consider the interaction in axisymmetric approximation, i.e. the pulsar rotation axis is assumed to be oriented along the line between the pulsar and the optical star and the effects related to the …
Since its launch in 2008, the Fermi Large Area Telescope (LAT) has detected over 200 -ray pulsars above 100 MeV. This population of pulsars is characterised by a rich diversity of light curve morphologies. Researchers have been using both the radio and -ray light curves to constrain the inclination and observer angles for each of these pulsars. At first, this was done using a by-eye technique and later via statistical approaches. We have also developed two novel statistical approaches that place the radio and -ray data on equal footing despite their disparate relative flux errors. We chose ele…
We present the first detailed joint modelling of both the timing and spectral properties during the outburst decay of transient anomalous X-ray pulsars. We consider the two sources XTE J1810-197 and CXOU J164710.2-455216, and describe the source decline in the framework of a twisted magnetosphere model, using Monte Carlo simulations of magnetospheric scattering and mimicking localized heat deposition at the NS surface following the activity. Our results support a picture in which a limited portion of the star surface close to one of the magnetic poles is heated at the outburst onset. The subse…
Globular clusters are source of gamma-ray radiation. At GeV energies, their emission is attributed to magnetospheric activity of millisecond pulsars residing in the clusters. Inverse Compton scattering of ambient photon fields on relativistic particles diffusing through cluster environment is thought to be the source of GeV-TeV emission of globular clusters. Using pair starved polar cap model gamma-ray emission from synthetic millisecond pulsar was modelled. In addition to pulsar emission characteristics, the synthetic pulsar model yielded spectra of electrons escaping pulsar magnetosphere. To…
$γ$-ray radiation from pulsars is usually thought to be mostly produced by the synchro-curvature losses of accelerated particles. Here we present a systematic study of all currently reported, good-quality Fermi-LAT pulsar spectral data. We do so by applying a model which follows the particle dynamics and consistently computes the emission of synchro-curvature radiation. By fitting observational data on a case by case basis, we are able to obtain constraints about the parallel electric field, the typical lengthscale over which particles emit the bulk of the detected radiation, and the number of…
We discuss the role of particle-in-cell (PIC) simulations in unveiling the origin of the emitting particles in PWNe. After describing the basics of the PIC technique, we summarize its implications for the quiescent and the flaring emission of the Crab Nebula, as a prototype of PWNe. A consensus seems to be emerging that, in addition to the standard scenario of particle acceleration via the Fermi process at the termination shock of the pulsar wind, magnetic reconnection in the wind, at the termination shock and in the Nebula plays a major role in powering the multi-wavelength signatures of PWNe…
Pulse profile modelling of accreting millisecond pulsars with disc occultation and its impact on parameter inference
Nanjing University（南京大学）；Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education（南京大学现代天文与天体物理教育部重点实验室）；Anton Pannekoek Institute for Astronomy, University of Amsterdam（阿姆斯特丹大学安东·潘内克天文研究所）；Gravitation and Astroparticle Physics Amsterdam (GRAPPA), University of Amsterdam（阿姆斯特丹大学引力与天体粒子物理学阿姆斯特丹中心）；University of Helsinki（赫尔辛基大学）；University of Turku（图尔库大学）
Pulsars emit pulsed emission across the entire electromagnetic spectrum and their light curve phenomenology is strongly dependent on energy. This is also true for the gamma-ray waveband. Continued detections by Fermi Large Area Telescope in the GeV band and ground-based Cherenkov telescopes in the TeV band (e.g., Crab and Vela above 1 TeV) raise important questions about our understanding of the electrodynamics and local environment of pulsar magnetospheres. We model energy-dependent light curves (as a function of geometry, e.g., pulsar inclination and observer angle) in the curvature radiatio…
Recent observations of the Crab pulsar show no evidence for a spectral break in the infrared regime. It is argued that the observations are consistent with a power-law spectrum in the whole observable infrared - optical range. This is taken as the starting point for an evaluation of how self-consistent incoherent synchrotron models fare in a comparison with observations. Inclusion of synchrotron self-absorption proves important as does the restriction on the observed size of the emission region imposed by the relativistic beaming thought to define the pulse profile. It is shown that the observ…
We present results from a leptonic emission code that models the spectral energy distribution of a pulsar wind nebula by solving a Fokker-Planck-type transport equation and calculating inverse Compton and synchrotron emissivities. We have created this time-dependent, multi-zone model to investigate changes in the particle spectrum as they traverse the pulsar wind nebula, by considering a time and spatially-dependent B-field, spatially-dependent bulk particle speed implying convection and adiabatic losses, diffusion, as well as radiative losses. Our code predicts the radiation spectrum at diffe…
Polarization is a powerful diagnostic tool to constrain the site of the high-energy pulsed emission and particle acceleration in gamma-ray pulsars. Recent particle-in-cell simulations of pulsar magnetosphere suggest that high-energy emission results from particles accelerated in the equatorial current sheet emitting synchrotron radiation. In this study, we re-examine the simulation data to compute the phase-resolved polarization properties. We find that the emission is mildly polarized and that there is an anticorrelation between the flux and the degree of linear polarization (on-pulse: ~15%, …
In the last decade ground-based Imaging Atmospheric Cherenkov Telescopes have discovered roughly 30 pulsar wind nebulae at energies above 100 GeV. We present first results from a leptonic emission code that models the spectral energy density of a pulsar wind nebula by solving the Fokker-Planck transport equation and calculating inverse Compton and synchrotron emissivities. Although models such as these have been developed before, most of them model the geometry of a pulsar wind nebula as that of a single sphere. We have created a time-dependent, multi-zone model to investigate changes in the p…
Since the launch of the Fermi telescope more than five years ago, many new gamma-ray pulsars have been discovered with intriguing properties challenging our current understanding of pulsar physics. Observation of the Crab pulsar furnish today a broad band analysis of the pulsed spectrum with phase-resolved variability allowing to refine existing model to explain pulse shape, spectra and polarization properties. The latter gives inside into the geometry of the emitting region as well as on the structure of the magnetic field. Based on an exact analytical solution of the striped wind with finite…
(abridged) Gamma-ray pulsars constitute a class of high and very high-energy emitters for which the known population is steadily increasing thanks to the Fermi/Large Area Telescope. In this paper, their gamma-ray luminosity and spectral features are explained in the framework of synchrotron radiation from particles located in the stripe of the pulsar wind. Apart from radiative losses, particles are also subject to a constant re-acceleration and reheating for instance by a magnetic reconnection induced electric field. The high-energy luminosity scales as $L_γ\approx 2\times10^{26} \textrm{W} \,…
Marsh et al. detected radio and optical pulsations from the binary system AR Scorpii (AR Sco). This system, with an orbital period of 3.56 h, is composed of a cool, low-mass star and a white dwarf with a spin period of 1.95 min. Optical observations by Buckley et al. showed that the polarimetric emission from the white dwarf is strongly linearly polarised ( up to $\sim40\%$) with periodically changing intensities. This periodic non-thermal emission is thought to be powered by the highly magnetised ($ 5 \times 10^{8} $ G) white dwarf that is spinning down. The morphology of the polarisation sig…
We investigate broadband emission properties of the pulsar wind nebula (PWN) 3C 58 using a spectral energy distribution (SED) model. We attempt to match simultaneously the broadband SED and spatial variations of X-ray emission in the PWN. We further the model to explain a possible far-IR feature of which a hint is recently suggested in 3C 58: a small bump at $\sim$$10^{11}$ GHz in the PLANCK and Herschel band. While external dust emission may easily explain the observed bump, it may be internal emission of the source implying an additional population of particles. Although significance for the…
An isolated pulsar is a rotating neutron star possessing a high magnetic dipole moment that generally makes a finite angle with its rotation axis. As a consequence, the emission of magnetic dipole radiation (MDR) continuously takes away its rotational energy. This process leads to a time decreasing angular velocity of the star that is usually quantified in terms of its braking index. While this simple mechanism is indeed the main reason for the spin evolution of isolated pulsars, it may not be the only cause of this effect. Most of young isolated pulsars present braking index values that are c…
We model the morphology and spectrum of a pulsar wind nebula using a leptonic emission code. This code is a time-dependent, multi-zone model that investigates the changes in the particle spectrum as they traverse the nebula. We calculate the synchrotron and inverse Compton emissivities at different positions in the nebula, obtaining the surface brightness versus the radius, and also the size of the nebula as a function of energy. We incorporate a time and spatially-dependent $B$-field, spatially-dependent bulk particle speed implying convection and adiabatic losses, diffusion, as well as radia…
PSR B1259-63/LS 2883 is a binary system in which a 48-ms pulsar orbits around a Be star in a high eccentric orbit with a long orbital period of about 3.4 yr. It is special for having asymmetric two-peak profiles in both the X-ray and the TeV light curves. Recently, an unexpected GeV flare was detected by $Fermi$ gamma-ray observatory several weeks after the last periastron passage. In this paper, we show that this observed GeV flare could be produced by the Doppler-boosted synchrotron emission in the bow shock tail. An anisotropic pulsar wind model, which mainly affects the energy flux injecti…
The rising cosmic ray positron fraction reported by the PAMELA collaboration has lead to a great deal of interest in astrophysical sources of energetic electrons and positrons, including pulsars. In this paper, we calculate the spectrum of synchrotron emission from electrons and positrons injected from 376 young pulsars (<10^6 years) contained in the ATNF catalog, and compare our results to observations. We find that if objects such as the Vela and Crab pulsars have injected ~10^48 erg or more in energetic electrons and/or positrons, they are expected to produce bright and distinctive features…
Particle acceleration is a fundamental process in many high-energy astrophysical environments and determines the spectral features of their synchrotron emission. We have studied the adiabatic stochastic acceleration (ASA) of electrons arising from the basic dynamics of magnetohydrodynamic (MHD) turbulence and found that the ASA acts to efficiently harden the injected electron energy spectrum. The dominance of the ASA at low energies and the dominance of synchrotron cooling at high energies result in a broken power-law shape of both electron energy spectrum and photon synchrotron spectrum. Furt…
The light curves of gamma-ray pulsars detected by the Fermi Large Area Telescope show great variety in profile shape and position relative to their radio profiles. Such diversity hints at distinct underlying magnetospheric and/or emission geometries for the individual pulsars. We implemented an offset-dipole magnetic field in an existing geometric pulsar modelling code which already includes static and retarded vacuum dipole fields. In our model, this offset is characterised by a parameter epsilon (with epsilon = 0 corresponding to the static dipole case). We constructed sky maps and light cur…
In this contribution we review the recent progress in the modeling of Pulsar Wind Nebulae (PWN). We start with a brief overview of the relevant physical processes in the magnetosphere, the wind-zone and the inflated nebula bubble. Radiative signatures and particle transport processes obtained from 3D simulations of PWN are discussed in the context of optical and X-ray observations. We then proceed to consider particle acceleration in PWN and elaborate on what can be learned about the particle acceleration from the dynamical structures called "wisps" observed in the Crab nebula. We also discuss…
The wealth of high-energy (E > 50 MeV) and very-high-energy (E > 100 GeV) data accumulated over the past few years have provided unprecedented opportunities to probe pulsar emission models. The Fermi Large Area Telescope (LAT) has now detected over 200 gamma-ray pulsars of vastly different ages, providing an extensive dataset of spectra and light curves compared to a mere decade ago. Ground-based Cherenkov telescopes deepened our appreciation of the mysterious richness of the pulsar mechanism by a surprise detection of pulsed emission up to 1 TeV from the Crab pulsar. These discoveries positio…
We present detailed optical photo-polarimetric observations of the recently-discovered white dwarf pulsar AR Scorpii. Our extensive dataset reveals that the polarized emission is remarkably stable and repeatable with spin, beat and orbital modulations. This has enabled us to construct a simple geometrical model which assumes that all of the optically polarized emission emanates from two diametrically opposed synchrotron emission regions on the white dwarf magnetosphere. We suggest that the observed polarimetric modulations occur as a result of an enhanced injection of relativistic electrons in…
The Fermi Large Area Telescope has revolutionised the $γ$-ray pulsar field, increasing the population to over 250 detected pulsars. The majority display spectra with exponential cutoffs in a narrow range around a few GeV. Models predicted cutoffs up to 100 GeV; it was therefore not expected that pulsars would be visible in the very-high-energy ($>$100 GeV) regime. Subsequent surprise discoveries by ground-based telescopes of pulsed emission from four pulsars above tens of GeV have marked the beginning of a new era, raising important questions about the electrodynamics and local environment of …
As shown by broad-band observations, pulsar wind nebulae (PWNe) are characterized by a broken power-law spectrum of synchrotron emission. Based on the modern magnetohydrodynamic (MHD) turbulence theories, we investigate the re-acceleration of electrons in the PWN through the adiabatic stochastic acceleration (ASA), which arises from fundamental dynamics of MHD turbulence. The ASA acts to flatten the injected energy spectrum of electrons at low energies, while synchrotron cooling results in a steep spectrum of electrons at high energies. Their dominance in different energy ranges leads to a fla…
Synchrotron radiation of ultra-relativistic particles accelerated in a pulsar wind nebula may dominate its spectrum up to gamma-ray energies. Because of the short cooling time of the gamma-ray emitting electrons, the gamma-ray emission zone is in the immediate vicinity of the acceleration site. The particle acceleration likely occurs at the termination shock of the relativistic striped wind, where multiple forced magnetic field reconnections provide strong magnetic fluctuations facilitating Fermi acceleration processes. The acceleration mechanisms imply the presence of stochastic magnetic fiel…
In this paper we study the generation of very high energy (VHE) emission in Crab-like pulsars driven by means of the feedback of Cherenkov drift waves on distribution of magnetospheric electrons. We have found that the unstable Cherenkov drift modes lead to the quasi-linear diffusion (QLD), keeping the pitch angles from vanishing, which in turn, maintains the synchrotron mechanism. Considering the Crab-like pulsars it has been shown that the growth rate of the Cherenkov drift instability (ChDI) is quite high, indicating high efficiency of the process. Analyzing the mechanism for the typical pa…
We propose a simple physical picture for the generation of coherent radio emission in the axisymmetric pulsar magnetosphere that is quite different from the canonical paradigm of radio emission coming from the magnetic polar caps. In this first paper we consider only the axisymmetric case of an aligned rotator. Our picture capitalizes on an important element of the MHD representation of the magnetosphere, namely the separatrix between the corotating closed-line region (the `dead zone') and the open field lines that originate in the polar caps. Along the separatrix flows the return current that…
PSR B1259-63/LS 2883 is an elliptical pulsar/Be star binary and emits broadband emissions from radio to TeV $γ$-rays. The massive star possesses an equatorial disc, which is inclined with the orbital plane of the pulsar. The non-thermal emission from the system is believed to be produced by the pulsar wind shock and the double-peak profiles in the X-ray and TeV $γ$-ray light curves are related to the phases of the pulsar passing through the disc region of the star. In this paper, we investigate the interactions between the pulsar wind and stellar outflows, especially with the presence of the d…
