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transitional millisecond pulsars (tmsps) switch, on roughly multi-year timescales, between rotation-powered radio millisecond pulsar (rmsp) and accretion-powered low-mass x-ray binary (lmxb) states. the tmsps have raised several questions related to the nature of accretion flow in their lmxb state and the mechanism tha... | timing observations of psr j1023+0038 during a low-mass x-ray binary state |
using the state-of-the-art ska precursor, the meerkat radio telescope, we explore the limits to precision pulsar timing of millisecond pulsars achievable due to pulse stochasticity (jitter). we report new jitter measurements in 15 of the 29 pulsars in our sample and find that the levels of jitter can vary dramatically ... | measurements of pulse jitter and single-pulse variability in millisecond pulsars using meerkat |
in this review we describe recent observational and theoretical developments in our understanding of pulsar winds and pulsar-wind nebulae (pwne). we put special emphasis on the results from observations of well-characterized pwne of various types (e.g., torus-jet and bowshock-tail), the most recent mhd modeling efforts... | pulsar-wind nebulae. recent progress in observations and theory |
the correlation between the charge radii differences in mirror nuclei pairs and the neutron skin thickness has been studied with the so-called finite range simple effective interaction over a wide mass region. the so far precisely measured charge radii difference data within their experimental uncertainty ranges in the... | correlations between charge radii differences of mirror nuclei and stellar observables |
modified expansion rates in the early universe prior to big bang nucleosynthesis are common in modified gravity theories, and can have a significant impact on the generation of dark matter, matter-antimatter asymmetry, primordial black holes and the primordial gravitational wave (pgw) spectrum. here we study the pgw sp... | primordial gravitational wave signals in modified cosmologies |
recent observations of x-ray pulsars at low luminosities allow, for the first time, the comparison of theoretical models of the emission from highly magnetized neutron star atmospheres at low mass-accretion rates (ṁ ≲ 1015 g s−1) with the broadband x-ray data. the purpose of this paper is to investigate spectral format... | x-ray emission from magnetized neutron star atmospheres at low mass-accretion rates. i. phase-averaged spectrum |
we report the discovery of seven new galactic pulsars with the canadian hydrogen intensity mapping experiment's fast radio burst (chime/frb) backend. these sources were first identified via single pulses in chime/frb, then followed up with chime/pulsar. four sources appear to be rotating radio transients, pulsar-like s... | first discovery of new pulsars and rrats with chime/frb |
we have analyzed in this work the updated sample of neutron star masses derived from the study of a variety of 96 binary systems containing at least one neutron star using bayesian methods. after updating the multimodality of the distributions found in previous works, we determined the maximum mass implied by the sampl... | the maximum mass of neutron stars may be higher than expected: an inference from binary systems |
the crab pulsar is the prime example of an emitter of giant pulses. these short, very bright pulses are thought to originate near the light cylinder, at ~1600 km from the pulsar. the pulsar's location inside the crab nebula offers an unusual opportunity to resolve the emission regions, using the nebula, which scatters ... | resolving the emission regions of the crab pulsar's giant pulses. ii. evidence for relativistic motion |
ultralight bosons are well-motivated particles from various physical and cosmological theories and can be spontaneously produced during the superradiant process, forming a dense hydrogenlike cloud around the spinning black hole. after the growth saturates, the cloud slowly depletes its mass through gravitational-wave e... | signatures of ultralight bosons in compact binary inspiral and outspiral |
we present the science case for the proposed daksha high energy transients mission. daksha will comprise of two satellites covering the entire sky from 1~kev to $>1$~mev. the primary objectives of the mission are to discover and characterize electromagnetic counterparts to gravitational wave source; and to study gam... | science with the daksha high energy transients mission |
we present daksha, a proposed high energy transients mission for the study of electromagnetic counterparts of gravitational wave sources, and gamma ray bursts. daksha will comprise of two satellites in low earth equatorial orbits, on opposite sides of earth. each satellite will carry three types of detectors to cover t... | daksha: on alert for high energy transients |
high time resolution radio surveys over the last few years have discovered a population of millisecond-duration transient bursts called fast radio bursts (frbs), which remain of unknown origin. frbs exhibit dispersion consistent with propagation through a cold plasma and dispersion measures indicative of an origin at c... | are the distributions of fast radio burst properties consistent with a cosmological population? |
the present study explores the f (r ,t ) modified gravity on the basis of observational data for three different compact stars with matter profile as anisotropic fluid without electric charge. in this respect, we adopt the well-known karmarker condition and assume a specific and interesting model for grr metric potenti... | realistic stellar anisotropic model satisfying karmarker condition in f(r, t) gravity |
the second data release from the gaia mission (gaia dr2) includes, among its billion entries, astrometric parameters for binary companions to a number of known pulsars, including white dwarf companions to millisecond pulsars (msps) and the non-degenerate components of so-called “black widow” and “redback” systems. we f... | binary pulsar distances and velocities from gaia data release 2 |
the recent discovery of gravitational waves from merging black holes has generated interest in primordial black holes as a possible component of dark matter. in this paper, we show that pulsar timing may soon have sufficient data to constrain 1 - 1000 m⊙ primordial black holes (pbhs) via the nondetection of a third-ord... | pulsar timing can constrain primordial black holes in the ligo mass window |
massive black hole binaries (mbhbs) are expected to form at the centre of merging galaxies during the hierarchical assembly of the cosmic structure, and are expected to be the loudest sources of gravitational waves (gws) in the low-frequency domain. however, because of the dearth of energy exchanges with background sta... | post-newtonian evolution of massive black hole triplets in galactic nuclei - ii. survey of the parameter space |
pulsar timing arrays are presently the only means to search for the gravitational wave stochastic background from super massive black hole binary populations, considered to be within the grasp of current or near-future observations. the stringent upper limit from the parkes pulsar timing array has been interpreted as e... | no tension between assembly models of super massive black hole binaries and pulsar observations |
the neutron-star interior composition explorer is an x-ray astrophysics payload that will be placed on the international space station. its primary science goal is to measure with high accuracy the pulse profiles that arise from the non-uniform thermal surface emission of rotation-powered pulsars. modeling general rela... | measuring neutron star radii via pulse profile modeling with nicer |
we argue that the localization of the repeating fast radio bursts (frbs) at ∼1 gpc excludes a rotationally powered type of radio emission (e.g., analogs of crab’s giant pulses coming from very young energetic pulsars) as the origin of frbs. | fast radio bursts’ emission mechanism: implication from localization |
the young, fast-spinning x-ray pulsar j0537-6910 displays an extreme glitch activity, with large spin-ups interrupting its decelerating rotation every ~100 d. we present nearly 13 yr of timing data from this pulsar, obtained with the rossi x-ray timing explorer. we discovered 22 new glitches and performed a consistent ... | pulsar spin-down: the glitch-dominated rotation of psr j0537-6910 |
the cosmic-ray flux of positrons is measured with high precision by the space-borne particle spectrometer ams-02. the hypothesis that pulsar wind nebulae (pwne) can significantly contribute to the excess of the positron (e+) cosmic-ray flux has been consolidated after the observation of a γ-ray emission at tev energies... | constraining positron emission from pulsar populations with ams-02 data |
in this work, we explore the applicability of standard theoretical models of accretion to the observed properties of m51 ulx-7. the spin-up rate and observed x-ray luminosity are evidence of a neutron star with a surface magnetic field of 2-7 × 1013 g, rotating near equilibrium. analysis of the x-ray light curve of the... | m51 ulx-7: superorbital periodicity and constraints on the neutron star magnetic field |
gravitational waves provide a new probe of the universe which can reveal a number of cosmological and astrophysical phenomena that cannot be observed by electromagnetic waves. different frequencies of gravitational waves are detected by different means. among them, precision measurements of pulsar timing provides a nat... | implication of pulsar timing array experiments on cosmological gravitational wave detection |
in the face of increasingly severe flood disasters, urban resilience is a new path for future urban development. based on a review of relevant literature on urban resilience, we focusing on flood disaster scenes, present the perspective of "pressure - state - response" to the urban resilience process decomposition base... | assessment of temporal and spatial progress of urban resilience in guangzhou under rainstorm scenarios |
we report the first radio interferometric search at 843 mhz for fast transients, particularly fast radio bursts (frbs). the recently recommissioned swinburne university of technology's digital backend for the molonglo observatory synthesis telescope array (the utmost) with its large collecting area (18 000 m2) and wide... | fast radio transient searches with utmost at 843 mhz |
we investigate the equation of state for the recently developed hybrid quark-meson-nucleon model under neutron-star conditions of β -equilibrium and charge neutrality. the model has the characteristic feature that, at increasing baryon density, the chiral symmetry is restored within the hadronic phase by lifting the ma... | chiral symmetry restoration by parity doubling and the structure of neutron stars |
constraints on neutron star masses and radii now come from a variety of sources: theoretical and experimental nuclear physics, astrophysical observations including pulsar timing, thermal and bursting x-ray sources, and gravitational waves, and the assumptions inherent to general relativity and causality of the equation... | neutron star mass and radius measurements |
in outburst, neutron star x-ray binaries produce less powerful jets than black holes at a given x-ray luminosity. this has made them more difficult to study as they fade towards quiescence. to explore whether neutron stars power jets at low accretion rates (lx ≲ 1036 erg s-1), we investigate the radio and x-ray propert... | disc-jet coupling in low-luminosity accreting neutron stars |
we measure the effects of interstellar scattering on average pulse profiles from 13 radio pulsars with simple pulse shapes. we use data from the lofar high band antennas, at frequencies between 110 and 190 mhz. we apply a forward fitting technique, and simultaneously determine the intrinsic pulse shape, assuming single... | scattering analysis of lofar pulsar observations |
we present coordinated chandra x-ray observatory and karl g. jansky very large array observations of the transitional millisecond pulsar psr j1023+0038 in its low-luminosity accreting state. the unprecedented five hours of strictly simultaneous x-ray and radio continuum coverage for the first time unambiguously show a ... | simultaneous chandra and vla observations of the transitional millisecond pulsar psr j1023+0038: anti-correlated x-ray and radio variability |
polarized radio emission from psr j1745-2900 has already been used to investigate the strength of the magnetic field in the galactic center (gc), close to sagittarius a*. here we report how persistent radio emission from this magnetar, for over four years since its discovery, has revealed large changes in the observed ... | large magneto-ionic variations toward the galactic center magnetar, psr j1745-2900 |
chaos theory is integrated with multi-gene genetic programming (mggp) engine as a new hybrid model for river flow forecasting. this is to be referred to as chaos-mggp and its performance is tested using daily historic flow time series at four gauging stations in two countries with a mix of both intermittent and perenni... | chaos-based multigene genetic programming: a new hybrid strategy for river flow forecasting |
the first pulsating ultraluminous x-ray source (pulx) to be identified is m82 x-2. after the discovery in 2014, nustar observed the m82 field 15 times throughout 2015 and 2016. in this paper, we report the results of pulsation searches in all of these data sets and find only one new detection. this new detection allows... | all at once: transient pulsations, spin-down, and a glitch from the pulsating ultraluminous x-ray source m82 x-2 |
we study the transport of high-energy particles in pulsar wind nebulae (pwn) using three-dimensional magnetohydrodynamic (mhd) and test-particle simulations, as well as a fokker-planck particle transport model. the latter includes radiative and adiabatic losses, diffusion, and advection on the background flow of the si... | diffusion in pulsar wind nebulae: an investigation using magnetohydrodynamic and particle transport models |
context. the nearby large magellanic cloud (lmc) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in γ-rays. the lmc was detected at 0.1-100 gev as an extended source with cgro/egret and using early observations with the fermi-lat. the emission was found to correlate with mass... | deep view of the large magellanic cloud with six years of fermi-lat observations |
context. the positron fraction in cosmic rays has recently been measured with improved accuracy up to 500 gev, and it was found to be a steadily increasing function of energy above ~10 gev. this behaviour contrasts with standard astrophysical mechanisms, in which positrons are secondary particles, produced in the inter... | a new look at the cosmic ray positron fraction |
we study explosion characteristics of ultra-stripped supernovae (sne), which are candidates of sne generating binary neutron stars (nss). as a first step, we perform stellar evolutionary simulations of bare carbon-oxygen cores of mass from 1.45 to 2.0 m⊙ until the iron cores become unstable and start collapsing. we the... | neutrino-driven explosions of ultra-stripped type ic supernovae generating binary neutron stars |
several theories exist to explain the source of the bright, millisecond duration pulses known as fast radio bursts (frbs). if the progenitors of frbs are non-cataclysmic, such as giant pulses from pulsars, pulsar-planet binaries, or magnetar flares, frb emission may be seen to repeat. we have undertaken a survey of the... | a survey of frb fields: limits on repeatability |
the large european array for pulsars (leap) is an experiment that harvests the collective power of europe's largest radio telescopes in order to increase the sensitivity of high-precision pulsar timing. as part of the ongoing effort of the european pulsar timing array, leap aims to go beyond the sensitivity threshold n... | leap: the large european array for pulsars |
we propose a dark-matter (dm) admixed density-dependent equation of state where the fermionic dm interacts with the nucleons via higgs portal. presence of dm can hardly influence the particle distribution inside neutron star (ns) but can significantly affect the structure as well as equation of state (eos) of ns. intro... | cooling of dark-matter admixed neutron stars with density-dependent equation of state |
we analyse the late time evolution of 12 supernovae (sne) occurring over the last ~41 yr, including nine type iip/l, two iib, and one ib/c, using ubvr optical data from the large binocular telescope (lbt) and difference imaging. we see late time (5-42 yr) emission from nine of the eleven type ii sne (eight type iip/l, ... | the late time optical evolution of twelve core-collapse supernovae: detection of normal stellar winds |
in this work, we present the results of 1 yr of upgraded giant metrewave radio telescope timing measurements of psr j0514-4002a, a 4.99-ms pulsar in a 18.8-d eccentric (e = 0.89) orbit with a massive companion located in the globular cluster ngc 1851. combining these data with earlier green bank telescope data, we grea... | upgraded giant metrewave radio telescope timing of ngc 1851a: a possible millisecond pulsar - neutron star system |
recent observations with the meerkat radio telescope reveal a unique population of faint nonthermal filaments pervading the central molecular zone, a region rich in molecular gas near the galactic center. some of those filaments are organized into groups of almost parallel filaments, seemingly sorted by their length, s... | probing cosmic-ray transport with radio synchrotron harps in the galactic center |
a class of relativistic astrophysical compact objects is analyzed in the modified finch-skea geometry described by the mit bag model equation of state of interior matter, $ p=\dfrac{1}{3}\left(\rho-4b\right) $ , where b is known as the bag constant. b plays an important role in determining the physical features and str... | anisotropic strange quark star in finch-skea geometry and its maximum mass for non-zero strange quark mass (ms≠ 0) |
the purpose of this paper consists in presenting models of compact stars described by a new class of exact solutions to the field equations, in the context of general relativity, for a fluid configuration which is locally anisotropic in the pressure. with current sensitivities, we considered a non-linear form of modifi... | self-gravitating anisotropic model in general relativity under modified van der waals equation of state: a stable configuration |
identifying as many gamma-ray pulsars as possible in the fermi large area telescope (lat) data helps test pulsar emission models by comparing predicted and observed properties for a large, varied sample with as little selection bias as possible. it also improves extrapolations from the observed population to estimate t... | searching a thousand radio pulsars for gamma-ray emission |
radio pulsars are unique laboratories for a wide range of physics and astrophysics. understanding how they are created, how they evolve and where we find them in the galaxy, with or without binary companions, is highly constraining of theories of stellar and binary evolution. pulsars' relationship with a recently disco... | radio pulsars: the neutron star population & fundamental physics |
it has recently been demonstrated that self-consistent particle-in-cell simulations of low-obliquity pulsar magnetospheres in flat spacetime show weak particle acceleration and no pair production near the poles. we investigate the validity of this conclusion in a more realistic spacetime geometry via general-relativist... | ab initio pulsar magnetosphere: the role of general relativity |
we construct equilibrium configurations of uniformly rotating neutron stars for selected relativistic mean-field nuclear matter equations of state (eos). we compute, in particular, the gravitational mass (m ), equatorial (req) and polar (rpol) radii, eccentricity, angular momentum (j ), moment of inertia (i ) and quadr... | fast rotating neutron stars with realistic nuclear matter equation of state |
the variable star ar scorpii (ar sco) was recently discovered to pulse in brightness every 1.97 min from ultraviolet wavelengths into the radio regime. the system is composed of a cool, low-mass star in a tight, 3.55-hour orbit with a more massive white dwarf. here we report new optical observations of ar sco that show... | polarimetric evidence of a white dwarf pulsar in the binary system ar scorpii |
lorentz symmetry violations can be parametrized by an effective field theory framework that contains both general relativity and the standard model of particle physics called the standard-model extension (sme). we present new constraints on pure gravity sme coefficients obtained by analyzing lunar laser ranging (llr) o... | testing lorentz symmetry with lunar laser ranging |
in this work, we assess the sensitivity reach of pulsar timing array (pta) measurements to probe pointlike primordial black holes (pbhs), with an extended mass distribution, which originate from collapsed fermi balls that are formed through the aggregation of asymmetric u(1) dark fermions trapped within false vacuum bu... | probing primordial black holes from a first order phase transition through pulsar timing and gravitational wave signals |
pulsar timing-array correlation measurements offer an exciting opportunity to test the nature of gravity in the cosmologically novel nanohertz gravitational wave regime. the stochastic gravitational wave background is assumed gaussian and random, while there are limited pulsar pairs in the sky. this brings theoretical ... | pulsar and cosmic variances of pulsar timing-array correlation measurements of the stochastic gravitational wave background |
our paper reviews the planned space-based gamma-ray telescope gamma-400 and evaluates in details its opportunities in the field of dark matter (dm) indirect searches. we estimated the gamma-400 mean sensitivity to the diphoton dm annihilation cross section in the galactic center for dm particle masses in the range of 1... | dark matter searches by the planned gamma-ray telescope gamma-400 |
fast radio bursts (frbs) are millisecond transients of unknown origin(s) occurring at cosmological distances. here we, for the first time, show time-integrated-luminosity functions and volumetric occurrence rates of non-repeating and repeating frbs against redshift. the time-integrated-luminosity functions of non-repea... | no redshift evolution of non-repeating fast radio burst rates |
we perform a sub-threshold follow-up search for continuous nearly monochromatic gravitational waves from the central compact objects associated with the supernova remnants (snrs) vela jr., cassiopeia a, and snr g347.3-0.5. across the three targets, we investigate the most promising ≈10,000 combinations of gravitational... | search for continuous gravitational waves from the central compact objects in supernova remnants cassiopeia a, vela jr., and g347.3-0.5 |
a pulsar timing array (pta) refers to a program of regular, high-precision timing observations of a widely distributed array of millisecond pulsars. here we review the status of the three primary pta projects and the joint international pulsar timing array project. we discuss current results related to ultra-low-freque... | gravitational wave research using pulsar timing arrays |
a sensitive test for whether a black hole is a wormhole, using astronomical observations, would be to look for perturbations in the orbit of a pulsar around the black hole, caused by a perturbing object on the other side of the wormhole. by observing a pulsar in an orbit like that of s2 around the supermassive black ho... | sensitive searches for wormholes |
we present pulse width measurements for a sample of radio pulsars observed with the meerkat telescope as part of the thousand-pulsar-array (tpa) programme in the meertime project. for a centre frequency of 1284 mhz, we obtain 762 w10 measurements across the total bandwidth of 775 mhz, where w10 is the width at the 10 p... | the thousand-pulsar-array programme on meerkat - vi. pulse widths of a large and diverse sample of radio pulsars |
common envelope evolution (cee) physics plays a fundamental role in the formation of binary systems, such as merging stellar gravitational wave sources, pulsar binaries, and type ia supernovae. a precisely constrained cee has become more important in the age of large surveys and gravitational wave detectors. we use an ... | the common envelope evolution outcome-a case study on hot subdwarf b stars |
wave dark matter (dm) represents a class of the most representative dm candidates. due to its periodic perturbation to spacetime, the wave dm can be detected with a galactic interferometer - pulsar timing array (pta). we perform in this letter a first analysis of applying the $\gamma$-ray pta to detect the wave dm, wit... | detecting stochastic wave dark matter with fermi-lat $\\gamma$-ray pulsar timing array |
detection of continuous gravitational waves from rapidly spinning neutron stars opens up the possibility of examining their internal physics. we develop a framework that leverages a future continuous gravitational wave detection to infer a neutron star's moment of inertia, equatorial ellipticity, and the component of t... | inferring neutron star properties with continuous gravitational waves |
fast radio bursts (frbs) must be powered by uniquely energetic emission mechanisms. this requirement has eliminated a number of possible source types, but several remain. identifying the physical nature of frb emitters arguably requires good localisation of more detections, as well as broad-band studies enabled by real... | the apertif radio transient system (arts): design, commissioning, data release, and detection of the first five fast radio bursts |
we develop a full four-dimensional numerical code to study scalar gravitational radiation emitted from binary systems and probe the vainshtein mechanism in situations that break the static and spherical symmetry, relevant for binary pulsars as well as black holes and neutron stars binaries. the present study focuses on... | scalar gravitational radiation from binaries: vainshtein mechanism in time-dependent systems |
we compare the parallaxes of stars from vlbi astrometry in the literature to those in the gaia dr2 catalog. our full sample contains young stellar objects, evolved agb stars, pulsars, and other radio stars. excluding agb stars, which show significant discrepancies between gaia and vlbi parallaxes, and stars in binary s... | comparison of gaia dr2 parallaxes of stars with vlbi astrometry |
pulsar halos are extended gamma-ray structures generated by electrons and positrons escaping from pulsar wind nebulae (pwne), considered a new class of gamma-ray sources. they are ideal indicators for cosmic-ray propagation in localized regions of the galaxy and particle escape process from pwne. the cosmic-ray diffusi... | gamma-ray pulsar halos in the galaxy |
with the development of ultra-intense laser technology, mev ions can be obtained from laser-foil interactions in the laboratory. these energetic ion beams can be applied in fast ignition for inertial confinement fusion, medical therapy, and proton imaging. however, these ions are mainly accelerated in the laser propaga... | hollow screw-like drill in plasma using an intense laguerre-gaussian laser |
we present a broadband integrated photonic polarization splitter and rotator (psr) using adiabatically tapered coupled waveguides with subwavelength grating (swg) claddings. the psr adiabatically rotates and splits the fundamental transverse-magnetic (tm0) input to the fundamental transverse-electric (te0) mode in the ... | broadband integrated polarization splitter and rotator using subwavelength grating claddings |
the self-excitation of plasma series resonance (psr) oscillations plays an important role in the electron heating dynamics in capacitively coupled radio-frequency (ccrf) plasmas. in a combined approach of pic/mcc simulations and a theoretical model based on an equivalent circuit, we investigate the self-excitation of p... | electron heating via self-excited plasma series resonance in geometrically symmetric multi-frequency capacitive plasmas |
the high-density behavior of stellar matter composed of nucleons and leptons under β equilibrium and charge neutrality conditions is studied with the skyrme parametrizations shown to be consistent (consistent skyrme parametrizations, cskp) with nuclear matter, pure neutron matter, symmetry energy and its derivatives in... | consistent skyrme parametrizations constrained by gw170817 |
a large sample of pulsars was observed as part of the meterwavelength single-pulse polarimetric emission survey. we carried out a detailed fluctuation spectral analysis that revealed periodic features in 46% of pulsars, including 22 pulsars where drifting characteristics were reported for the first time. the pulsar pop... | meterwavelength single-pulse polarimetric emission survey. ii. the phenomenon of drifting subpulses |
in this study, we propose a classification scheme for the phenomenon of subpulse drifting in pulsars. we have assembled an exhaustive list of pulsars that exhibit subpulse drifting from previously published results as well as recent observations using the giant meterwave radio telescope. we have estimated detailed phas... | classification of subpulse drifting in pulsars |
a fundamental question regarding the galactic center excess (gce) is whether the underlying structure is pointlike or smooth, often framed in terms of a millisecond pulsar or annihilating dark matter (dm) origin for the emission. we show that bayesian neural networks (nns) have the potential to resolve this debate. in ... | galactic center excess in a new light: disentangling the γ -ray sky with bayesian graph convolutional neural networks |
pulsar wind nebulae (pwne) represent the largest class of sources that upcoming γ-ray surveys will detect. therefore, accurate modelling of their global emission properties is one of the most urgent problems in high-energy astrophysics. correctly characterizing these dominant objects is a needed step to allow γ-ray sur... | modelling the γ-ray pulsar wind nebulae population in our galaxy |
recently, it has been discovered that the transition of x-ray pulsars to the low luminosity state ( $l\lesssim 10^{35}\, {\rm erg\ \rm s^{-1}}$ ) is accompanied by a dramatic spectral change. that is, the typical power-law-like spectrum with high-energy cut-off transforms into a two-component structure with a possible ... | spectrum formation in x-ray pulsars at very low mass accretion rate: monte carlo approach |
we present a comprehensive census of x-ray millisecond pulsars (msps) in 29 galactic globular clusters (gcs), including 68 msps with confirmed x-ray luminosities and 107 msps with x-ray upper limits. we compile previous x-ray studies of gc msps, and add new analyses of six msps (psrs j1326-4728a, j1326-4728b, j1518+020... | a census of x-ray millisecond pulsars in globular clusters |
we report detections of scintillation arcs for pulsars in globular clusters m5, m13 and m15 for the first time using the five-hundred-meter aperture spherical radio telescope (fast). from observations of these arcs at multiple epochs, we infer that screen-like scattering medium exists at distances 4.1−0.3+0.2, 6.7−0.2+... | galactic interstellar scintillation observed from four globular cluster pulsars by fast |
a linear transformer driver (ltd) generator capable of delivering up to 0.9 ma current pulses with 160 ns rise time has been assembled and commissioned at university of california san diego. the machine is an upgrade of the ltd-iii pulser from sandia national laboratories, consisting of 40 capacitors and 20 spark gap s... | ma-class linear transformer driver for z -pinch research |
the imaging quality of in-line digital holography is challenged by the twin-image and aliasing effects because sensors only respond to intensity and pixels are of finite size. as a result, phase retrieval and pixel super-resolution techniques serve as two essential ingredients for high-fidelity and high-resolution holo... | generalized optimization framework for pixel super-resolution imaging in digital holography |
in the present article, the solution of the einstein-maxwell field equations in the presence of a massive scalar field under the brans-dicke (bd) gravity is obtained via embedding approach, which describes a charged anisotropic strange star model. the interior spacetime is described by a spherically symmetric static me... | anisotropic stars via embedding approach in brans-dicke gravity |
braking index measurements offer the opportunity to explore the processes affecting the long-term spin evolution of pulsars and possible evolutionary connections between the various pulsar populations. in most cases, such measurements are difficult because of the presence of short-term phenomena, such as glitches and t... | new long-term braking index measurements for glitching pulsars using a glitch-template method |
fast radio bursts (frbs) are millisecond-time-scale radio transients, the origins of which are predominantly extragalactic and likely involve highly magnetized compact objects. frbs undergo multipath propagation, or scattering, from electron density fluctuations on sub-parsec scales in ionized gas along the line of sig... | scattering variability detected from the circumsource medium of frb 20190520b |
the low-frequency linearly polarised radio source population is largely unexplored. however, a renaissance in low-frequency polarimetry has been enabled by pathfinder and precursor instruments for the square kilometre array. in this second paper from the polarised galactic and extragalactic all-sky mwa survey-the polar... | the polarised gleam survey (pogs) ii: results from an all-sky rotation measure synthesis survey at long wavelengths |
we study inflation driven by a dilaton and an axion, both of which are coupled to a su(2) gauge field. we find that the inflation driven by the dilaton occurs in the early stage of inflation during which the gauge field grows due to the gauge-kinetic function. when the energy density of magnetic fields catches up with ... | chiral primordial gravitational waves from dilaton induced delayed chromonatural inflation |
this reference work gathers all of the latest research in the supernova field areas to create a definitive source book on supernovae, their remnants and related topics. it includes each distinct subdiscipline, including stellar types, progenitors, stellar evolution, nucleosynthesis of elements, supernova types, neutron... | handbook of supernovae |
accretion-induced collapse (aic) from oxygen/neon/magnesium composition white dwarf (onemg wd) + stripped helium (he) star binaries is one promising channel to form peculiar neutron star objects. it has been discussed that the wd's magnetic field may alter the accretion phase in the wd binary evolution. by considering ... | the magnetized white dwarf + helium star binary evolution with accretion-induced collapse |
aims: the aim of this paper is to investigate the transition of a strongly magnetized neutron star into the accretion regime with very low accretion rate.methods: for this purpose, we monitored the be-transient x-ray pulsar gro j1008-57 throughout a full orbital cycle. the current observational campaign was performed w... | stable accretion from a cold disc in highly magnetized neutron stars |
we present a radio continuum and linear polarization study of the galactic supernova remnant (snr) g57.2+0.8, which may host the recently discovered magnetar sgr 1935+2154. the radio snr shows the typical radio continuum spectrum of a mature supernova remnant with a spectral index of α =-0.55+/- 0.02 and moderate polar... | a radio continuum and polarization study of snr g57.2+0.8 associated with magnetar sgr 1935+2154 |
we report here on initial results from the thousand-pulsar-array (tpa) programme, part of the large survey project 'meertime' on the meerkat telescope. the interferometer is used in the tied-array mode in the band from 856 to 1712 mhz, and the wide band coupled with the large collecting area and low receiver temperatur... | the thousand-pulsar-array programme on meerkat - i. science objectives and first results |
we consider an uncharged anisotropic stellar model with two distinct equations of state in general relativity. the core layer has a quark matter distribution with a linear equation of state. the envelope layer has a matter distribution which is quadratic. the interfaces between the core, envelope and the vacuum exterio... | compact relativistic star with quadratic envelope |
the high altitude water cherenkov (hawc) telescope recently observed extended emission around the geminga and psr b0656+14 pulsar wind nebulae (pwne). these observations have been used to estimate cosmic-ray (cr) diffusion coefficients near the pwne that appear to be more than two orders of magnitude smaller than the d... | cosmic-ray propagation in light of the recent observation of geminga |
rotating neutron stars, or pulsars and magnetars, are plausibly the source of power behind many astrophysical systems, such as gamma-ray bursts, supernovae, pulsar wind nebulae, and supernova remnants. in the past several years, three-dimensional (3d) numerical simulations made it possible to compute pulsar spin-down l... | three-dimensional analytical description of magnetized winds from oblique pulsars |
in the beginning of 2023, the be transient x-ray pulsar rx j0440.9+4431 underwent a first-ever giant outburst observed from the source peaking in the beginning of february and reaching peak luminosity of ≈4.3 × 1037 erg s-1. here, we present the results of a detailed spectral and temporal study of the source based on n... | rx j0440.9+4431: another supercritical x-ray pulsar |
scalar-tensor theories of gravity are extensions of general relativity (gr) including an extra, nonminimally coupled scalar degree of freedom. a wide class of these theories, albeit indistinguishable from gr in the weak field regime, predicts a radically different phenomenology for neutron stars, due to a nonperturbati... | highly compact neutron stars in scalar-tensor theories of gravity: spontaneous scalarization versus gravitational collapse |
pulsar wind nebulae (pwne) are the main gamma-ray emitters in the galactic plane. they are diffuse nebulae that emit nonthermal radiation. pulsar winds, relativistic magnetized outflows from the central star, shocked in the ambient medium produce a multiwavelength emission from the radio through gamma-rays. although th... | icecube search for high-energy neutrino emission from tev pulsar wind nebulae |
the five-hundred-meter aperture spherical radio telescope (fast) is the largest single-dish radio telescope in the world. in this paper, we make forecast on the fast h i large-scale structure survey by mock observations. we consider a drift scan survey with the l-band 19 beam receiver, which may be commensal with the p... | forecast for fast: from galaxies survey to intensity mapping |
the two leading hypotheses for the galactic center excess (gce) in the fermi data are an unresolved population of faint millisecond pulsars (msps) and dark-matter (dm) annihilation. the dichotomy between these explanations is typically reflected by modeling them as two separate emission components. however, point sourc... | extracting the galactic center excess' source-count distribution with neural nets |
we report the first discovery of a fast radio burst (frb), frb 20200125a, by the green bank northern celestial cap (gbncc) pulsar survey conducted with the green bank telescope at 350 mhz. frb 20200125a was detected at a galactic latitude of 58°43 with a dispersion measure of 179 pc cm3, while electron density models p... | first discovery of a fast radio burst at 350 mhz by the gbncc survey |
since the day of its explosion, sn 1987a (sn87a) was closely monitored with the aim to study its evolution and to detect its central compact relic. the detection of neutrinos from the supernova strongly supports the formation of a neutron star (ns). however, the constant and fruitless search for this object has led to ... | indication of a pulsar wind nebula in the hard x-ray emission from sn 1987a |
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