abstract stringlengths 3 192k | title stringlengths 4 857 |
|---|---|
gravitational waves with frequencies below 1 nhz are notoriously difficult to detect. with periods exceeding current experimental lifetimes, they induce slow drifts in observables rather than periodic correlations. observables with well-known intrinsic contributions provide a means to probe this regime. in this work, w... | using pulsar parameter drifts to detect sub-nanohertz gravitational waves |
the direct detection of gravitational waves provides the opportunity to measure fundamental aspects of gravity which have never been directly probed before, including the polarization of gravitational waves. in the context of searches for continuous waves from known pulsars, we present novel methods to detect signals o... | probing dynamical gravity with the polarization of continuous gravitational waves |
recent progress in the determination of both masses and radii of neutron stars has put strong constraints on the equation of state (eos) above the nuclear saturation density. within a confining quark matter model, we propose an anisotropic star consisting of a homogeneous and unpaired charge-neutral 3-flavor interactin... | anisotropic quark stars in einstein-gauss-bonnet theory |
ultralight particles (ma∼10-21- 10-22 ev ) with axionlike couplings to other particles can be candidates for fuzzy dark matter (fdm) if the axion decay constant fa∼1017 gev . if a compact star is immersed in such a low-mass axionic potential, it develops a long-range field outside the star. this axionic field is radiat... | constraints on ultralight axions from compact binary systems |
an isotropic stochastic background of nanohertz gravitational waves creates excess residual power in pulsar-timing-array datasets, with characteristic interpulsar correlations described by the hellings-downs function. these correlations appear as nondiagonal terms in the noise covariance matrix, which must be inverted ... | accurate characterization of the stochastic gravitational-wave background with pulsar timing arrays by likelihood reweighting |
over the past decade, the discovery of three unique stellar populations and a large number of confirmed pulsars within the globular cluster terzan 5 has raised questions over its classification. using the long-term radio pulsar timing of 36 ms pulsars in the cluster core, we provide new measurements of key physical pro... | using long-term millisecond pulsar timing to obtain physical characteristics of the bulge globular cluster terzan 5 |
the aim of this work is to formulate two new solutions by decoupling the field equations via a minimal geometric deformation in the context of self-interacting brans-dicke gravity. we introduce an extra source in the anisotropic fluid distribution to generate new analogs of existing solutions. the radial metric functio... | isotropization and complexity of decoupled solutions in self-interacting brans-dicke gravity |
we investigate the scalar-tensor gravity of damour and esposito-farèse (def), which predicts nontrivial phenomena in the nonperturbative strong-field regime for neutron stars (nss). instead of solving the modified tolman-oppenheimer-volkoff equations, we construct reduced-order surrogate models, coded in the pyuc(stgro... | reduced-order surrogate models for scalar-tensor gravity in the strong field regime and applications to binary pulsars and gw170817 |
precise and reliable measurements of the masses and radii of neutron stars with a variety of masses would provide valuable guidance for improving models of the properties of cold matter with densities above the saturation density of nuclear matter. several different approaches for measuring the masses and radii of neut... | observational constraints on neutron star masses and radii |
we report the detection of 48 millisecond pulsars (msps) out of 75 observed thus far using the low-frequency array (lofar) in the frequency range 110-188 mhz. we have also detected three msps out of nine observed in the frequency range 38-77 mhz. this is the largest sample of msps ever observed at these low frequencies... | a lofar census of millisecond pulsars |
this paper investigates a novel intelligent reflecting surface (irs)-based symbiotic radio (sr) system architecture consisting of a transmitter, an irs, and an information receiver (ir). the primary transmitter communicates with the ir and at the same time assists the irs in forwarding information to the ir. based on t... | a novel wireless communication paradigm for intelligent reflecting surface based symbiotic radio systems |
47 tuc x9 is a low-mass x-ray binary (lmxb) in the globular cluster 47 tucanae, and was previously thought to be a cataclysmic variable. however, miller-jones et al. recently identified a radio counterpart to x9 (inferring a radio/x-ray luminosity ratio consistent with black hole lmxbs), and suggested that the donor st... | the ultracompact nature of the black hole candidate x-ray binary 47 tuc x9 |
psr j2032+4127 is a γ-ray and radio-emitting pulsar which has been regarded as a young luminous isolated neutron star. however, its recent spin-down rate has extraordinarily increased by a factor of 2. we present evidence that this is due to its motion as a member of a highly-eccentric binary system with an ∼15-m⊙ be s... | the binary nature of psr j2032+4127 |
galactic plane radio surveys play a key role in improving our understanding of a wide range of astrophysical phenomena. performing such a survey using the latest interferometric telescopes produces large data rates necessitating a shift towards fully or quasi-real-time data analysis with data being stored for only the ... | the mpifr-meerkat galactic plane survey - i. system set-up and early results |
context. we present a detailed view of the pulsar wind nebula (pwn) hess j1825-137. we aim to constrain the mechanisms dominating the particle transport within the nebula, accounting for its anomalously large size and spectral characteristics.aims: the nebula was studied using a deep exposure from over 12 years of h.e.... | particle transport within the pulsar wind nebula hess j1825-137 |
modeling of the nicer x-ray waveform of the pulsar psr j0030+0451, aimed at constraining the neutron star mass and radius, has inferred surface hot spots (the magnetic polar caps) that imply significantly nondipolar magnetic fields. to this end, we investigate magnetic field configurations that comprise offset dipole-p... | the multipolar magnetic field of the millisecond pulsar psr j0030+0451 |
the recent discovery of a new population of ultrahigh-energy gamma-ray sources with spectra extending beyond 100 tev revealed the presence of galactic pevatrons-cosmic-ray factories accelerating particles to pev energies. these sources, except for the one associated with the crab nebula, are not yet identified. with an... | on the potential of bright, young pulsars to power ultrahigh gamma-ray sources |
binary neutron stars have been observed as millisecond pulsars, gravitational-wave sources, and as the progenitors of short gamma-ray bursts and kilonovae. massive stellar binaries that evolve into merging double neutron stars are believed to experience a common-envelope episode. during this episode, the envelope of a ... | stellar response after stripping as a model for common-envelope outcomes |
ligo and virgo have initiated the era of gravitational-wave (gw) astronomy; but in order to fully explore gw frequency spectrum, we must turn our attention to innovative techniques for gw detection. one such approach is to use binary systems as dynamical gw detectors by studying the subtle perturbations to their orbits... | detecting stochastic gravitational waves with binary resonance |
the crab pulsar is a typical example of a young, rapidly spinning, strongly magnetized neutron star that generates broadband electromagnetic radiation by accelerating charged particles to near light speeds in its magnetosphere1. details of this emission process so far remain poorly understood. measurement of polarizati... | phase-resolved x-ray polarimetry of the crab pulsar with the astrosat czt imager |
while a growing body of research indicates that relativistic magnetic reconnection is a prodigious source of particle acceleration in high-energy astrophysical systems, the dominant acceleration mechanism remains controversial. using a combination of fully kinetic simulations and theoretical analysis, we demonstrate th... | determining the dominant acceleration mechanism during relativistic magnetic reconnection in large-scale systems |
psr j0540-6919 is the second-most energetic radio pulsar known and resides in the large magellanic cloud. like the crab pulsar, it is observed to emit giant radio pulses (gps). we used the newly commissioned ptuse instrument on the meerkat radio telescope to search for gps across three observations. in a total integrat... | the thousand-pulsar-array programme on meerkat - iii. giant pulse characteristics of psr j0540-6919 |
magnetic fields permeate the diffuse interstellar medium (ism) of the milky way, and are essential to explain the dynamical evolution and current shape of the galaxy. magnetic fields reveal themselves via their influence on the surrounding matter, and as such are notoriously hard to measure independently of other trace... | disentangling the faraday rotation sky |
we investigate the joint effect of cosmological phase transitions, thermal light dark matter, and lepton asymmetry on big bang nucleosynthesis and the cosmic microwave background. we find that all of them can modify the predictions of the effective number of neutrino species and primordial nucleosynthesis. in turn, we ... | constraints on new physics around the mev scale with cosmological observations |
the recent discovery of a radio-emitting neutron star with an ultralong spin period of 76 s, psr j0901-4046, raises a fundamental question on how such a slowly rotating magnetized object can be active in the radio band. a canonical magnetic field of 1.3 ×1014 g estimated from the pulsar period and its time derivative i... | ultraslow psr j0901-4046 with an ultrahigh magnetic field of 3.2 ×1016 g |
the sensitivity and field of view of the canadian hydrogen intensity mapping experiment (chime) has enabled its fast radio burst (frb) backend to detect thousands of frbs. however, the low angular resolution of chime prevents it from localizing most frbs to their host galaxies. very long baseline interferometry (vlbi) ... | tone: a chime/frb outrigger pathfinder for localizations of fast radio bursts using very long baseline interferometry |
the coherent oscillation of axionic fields naturally drives copious production of dark photon particles in the early universe, due to resonance and tachyonic enhancement. during the process, energy is abruptly transferred from the former to the latter, sourcing gravitational-wave generation. the resulting gravitational... | implications of gravitational-wave production from dark photon resonance to pulsar-timing observations and effective number of relativistic species |
we report on analysis of observations of the bright transient x-ray pulsar (xrp) swift j0243.6+6124 obtained during its 2017-2018 giant outburst with insight-hxmt, nustar, and swift observatories. we focus on the discovery of a sharp state transition of the timing and spectral properties of the source at super-eddingto... | hot disc of the swift j0243.6+6124 revealed by insight-hxmt |
psr b1820-30a is located in the globular cluster ngc 6624 and is the closest known pulsar to the centre of any globular cluster. we present more than 25 yr of high-precision timing observations of this millisecond pulsar and obtain four rotational frequency time derivative measurements. modelling these higher order der... | evidence for an intermediate-mass black hole in the globular cluster ngc 6624 |
the frequency-dependent periodic active window of the fast radio burst frb 180916.j0158+65 (frb 180916b) was observed recently. in this letter, we propose that a be/x-ray binary (bexrb) system, which is composed of a neutron star (ns) and a be star with a circumstellar disk, might be the source of a repeating frb with ... | periodic activities of repeating fast radio bursts from be/x-ray binary systems |
the hawc collaboration has observed gamma rays at energies above 56 tev from a collection of nine sources. it has been suggested that this emission could be hadronic in nature, requiring that these systems accelerate cosmic-ray protons or nuclei up to pev-scale energies. in this paper, we instead show that the spectra ... | the highest energy hawc sources are likely leptonic and powered by pulsars |
we develop a new nonparametric method to reconstruct the equation of state (eos) of a neutron star with multimessenger data. as a universal function approximator, the feed-forward neural network (ffnn) with one hidden layer and a sigmoidal activation function can approximately fit any continuous function. thus, we are ... | bayesian nonparametric inference of the neutron star equation of state via a neural network |
in this work we investigate neutron stars (ns) in f(script r,t) gravity for the case r+2λscript t, script r is the ricci scalar and script t the trace of the energy-momentum tensor. the hydrostatic equilibrium equations are solved considering realistic equations of state (esos). the ns masses and radii obtained are sub... | neutron stars in f(script r,t) gravity using realistic equations of state in the light of massive pulsars and gw170817 |
pulsar timing array collaborations have recently reported evidence for a noise process with a common spectrum among the millisecond pulsars in the arrays. the spectral properties of this common-noise process are consistent with expectations for an isotropic gravitational-wave background (gwb) from inspiralling supermas... | evaluating the prevalence of spurious correlations in pulsar timing array data sets |
supernova explosion and the associated neutron star (ns) natal kicks are important events on a pathway of a binary to become a gravitational wave source, an x-ray binary, or a millisecond radio pulsar. weak natal kicks often lead to binary survival, while strong kicks frequently disrupt the binary. in this article, we ... | combined analysis of neutron star natal kicks using proper motions and parallax measurements for radio pulsars and be x-ray binaries |
in this paper we study the dynamics of neutral, electrically charged and magnetized particles around deformed electrically and magnetically charged reissner-nordström black holes. for the neutral test particles motion, it is shown that the radius of the innermost stable circular orbits (iscos) decrease with the increas... | test particles dynamics around deformed reissner-nordström black hole |
gravitational waves (gws) can offer a novel window into the structure and dynamics of neutron stars. here we present the first search for long-duration quasimonochromatic gw transients triggered by pulsar glitches. we focus on two glitches observed in radio timing of the vela pulsar (psr j0835-4510) on 12 december 2016... | first search for long-duration transient gravitational waves after glitches in the vela and crab pulsars |
pulsars with high spin-down power produce relativistic winds radiating a non-negligible fraction of this power over the whole electromagnetic range from radio to gamma-rays in the pulsar wind nebulae (pwne). the rest of the power is dissipated in the interactions of the pwne with the ambient interstellar medium (ism). ... | pulsar wind nebulae with bow shocks: non-thermal radiation and cosmic ray leptons |
the nanohertz stochastic gravitational wave background (sgwb) is an excellent early universe laboratory for testing the fundamental properties of gravity. in this letter, we elucidate on the full potential of pulsar timing array (pta) by utilizing cosmic variance-limited, or rather experimental noise-free, correlation ... | testing gravity with cosmic variance-limited pulsar timing array correlations |
we investigate the use of harmonic analysis techniques to perform measurements of the angular power spectrum on mock pulsar timing data for an isotropic stochastic gravitational-wave background (sgwb) with a dimensionless strain amplitude $a_{\text{gw}}=2 \times 10^{-15}$ and spectral index $\gamma_{\text{gw}}=13/3$. w... | harmonic analysis for pulsar timing arrays |
we present an analysis of a densely repeating sample of bursts from the first repeating fast radio burst, frb 121102. we reanalyzed the data used by gourdji et al. and detected 93 additional bursts using our single-pulse search pipeline. in total, we detected 133 bursts in three hours of data at a center frequency of 1... | comprehensive analysis of a dense sample of frb 121102 bursts |
the transitional millisecond pulsar (msp) binary system psr j1023+0038 re-entered an accreting state in 2013 june in which it bears many similarities to low-mass x-ray binaries (lmxbs) in quiescence or near-quiescence. at a distance of just 1.37 kpc, psr j1023+0038 offers an unsurpassed ability to study low-level accre... | radio imaging observations of psr j1023+0038 in an lmxb state |
we analyze the spectrum of gravitational waves generated by the induced spectrum of tensor fluctuation during warm natural inflation. in our previous work it has been demonstrated that an epoch of warm natural inflation can lead to cosmologically relevant dark matter production in the form of primordial black holes. he... | induced gravitational waves via warm natural inflation |
explosive astrophysical transients at cosmological distances can be used to place precision tests of the basic assumptions of relativity theory, such as lorentz invariance, the photon zero-mass hypothesis, and the weak equivalence principle (wep). signatures of lorentz invariance violations (liv) include vacuum dispers... | testing fundamental physics with astrophysical transients |
transient gravitational waves (aka gravitational wave bursts) within the nanohertz frequency band could be generated by a variety of astrophysical phenomena such as the encounter of supermassive black holes, the kinks or cusps in cosmic strings, or other as-yet-unknown physical processes. radio pulses emitted from mill... | searching for gravitational wave burst in pulsar-timing-array data with piecewise linear functions |
recently, a few-degrees extended γ -ray halo in the direction of the geminga pulsar has been detected by hawc, milagro and fermi-lat. these observations can be interpreted with positrons (e+) and electrons (e-) accelerated by the geminga pulsar wind nebula (pwn), released in a galactic environment with a low diffusion ... | evidences of low-diffusion bubbles around galactic pulsars |
in this work we provide a framework for modelling compact stars in which the interior matter distribution obeys a generalised chaplygin equation of state. the interior geometry of the stellar object is described by a spherically symmetric line element which is simultaneously co-moving and isotropic with the exterior sp... | anisotropic stars obeying chaplygin equation of state |
with the continuous upgrade of detectors, greater numbers of gravitational wave (gw) events have been captured by the ligo scientific collaboration and virgo collaboration (lvc), which offer a new avenue to test general relativity and explore the nature of gravity. although various model-independent tests have been per... | constraining scalar-tensor theories using neutron star-black hole gravitational wave events |
we investigate evolutionary pathways leading to neutron star (ns) formation through the collapse of oxygen-neon white dwarf (one wd) stars in interacting binaries. we consider (1) non-dynamical mass transfer where an one wd approaches the chandrasekhar mass leading to accretion-induced collapse (aic) and (2) dynamical ... | on the formation of neutron stars via accretion-induced collapse in binaries |
we present results from the first all-sky radio survey in circular polarization. the survey uses the murchison widefield array (mwa) to cover 30 900 sq deg, over declinations south of +30° and north of -86° centred at 200 mhz (over a 169-231 mhz band). we achieve a spatial resolution of ∼3 arcmin and a typical sensitiv... | an all-sky survey of circular polarization at 200 mhz |
we perform ab initio particle-in-cell (pic) simulations of a pulsar magnetosphere with electron-positron plasma produced only in the regions close to the neutron star surface. we study how the magnetosphere transitions from the vacuum to a nearly force-free configuration. we compare the resulting force-free-like config... | electron-positron pair flow and current composition in the pulsar magnetosphere |
recently, a 16-day periodicity in a fast radio burst was reported. we propose that this 16-day periodicity may be due to forced precession of the neutron star by a fallback disk. when the rotation axis is misaligned with respect to the normal direction of the disk plane, the neutron star will precess. the eccentricity ... | periodicity in fast radio bursts due to forced precession by a fallback disk |
the possibility that in the mass range around $10^{-12}\ m_\odot$ most of dark matter constitutes of primordial black holes (pbhs) is a very interesting topic. to produce pbhs with this mass, the primordial scalar power spectrum needs to be enhanced to the order of 0.01 at the scale $k\sim 10^{12}\ \text{mpc}^{-1}$. th... | primordial black holes and secondary gravitational waves from k/g inflation |
radio pulsars in short-period eccentric binary orbits can be used to study both gravitational dynamics and binary evolution. the binary system containing psr j1141-6545 includes a massive white dwarf (wd) companion that formed before the gravitationally bound young radio pulsar. we observed a temporal evolution of the ... | lense-thirring frame dragging induced by a fast-rotating white dwarf in a binary pulsar system |
nearby pulsars have been suggested as sources of ∼tev e+/e- cosmic ray (cr) excess on the earth. the high-altitude water cherenkov observatory (hawc) detected extended tev emission regions in the direction of two nearby middle-aged pulsars, geminga and psr b0656+14. by modelling the tev emission as inverse compton emis... | positron flux and γ-ray emission from geminga pulsar and pulsar wind nebula |
the on-going arecibo pulsar-alfa (palfa) survey began in 2004 and is searching for radio pulsars in the galactic plane at 1.4 ghz. here we present a comprehensive description of one of its main data reduction pipelines that is based on the presto software and includes new interference-excision algorithms and candidate ... | arecibo pulsar survey using alfa. iv. mock spectrometer data analysis, survey sensitivity, and the discovery of 40 pulsars |
in this paper a description is given of the sfxc software correlator, developed and maintained at the joint institute for vlbi in europe (jive). the software is designed to run on generic linux-based computing clusters. the correlation algorithm is explained in detail, as are some of the novel modes that software corre... | the sfxc software correlator for very long baseline interferometry: algorithms and implementation |
the highest-energy known gamma-ray sources are all located within 0°5 of extremely powerful pulsars. this raises the question of whether ultra-high-energy (uhe; >56 tev) gamma-ray emission is a universal feature expected near pulsars with a high spin-down power. using four years of data from the high altitude water ... | evidence that ultra-high-energy gamma rays are a universal feature near powerful pulsars |
fast radio bursts (frbs) can be scattered by ionized gas in their local environments, host galaxies, intervening galaxies along their lines of sight (los), the intergalactic medium, and the milky way. the relative contributions of these different media depend on their geometric configuration and the internal properties... | constraining galaxy halos from the dispersion and scattering of fast radio bursts and pulsars |
radio pulsars provide some of the most important constraints for our understanding of matter at supranuclear densities. so far, these constraints are mostly given by precision mass measurements of neutron stars (ns). by combining single measurements of the two most massive pulsars, j0348+0432 and j0740+6620, the result... | constraining the dense matter equation-of-state with radio pulsars |
we study an impact of asymmetric dark matter on properties of the neutron stars and their ability to reach the two solar masses limit, which allows us to present a new range of masses of dark matter particles and their fractions inside the star. our analysis is based on the observational fact of the existence of two pu... | neutron stars: new constraints on asymmetric dark matter |
the tibet asγ experiment provided the first measurement of the total diffuse gamma-ray emission from the galactic disk in the sub-pev energy range. based on the analysis of tev sources included in the h.e.s.s. galactic plane survey catalog, we predict the expected contribution of unresolved pulsar-powered sources in th... | unresolved sources naturally contribute to pev gamma-ray diffuse emission observed by tibet asγ |
two recent discoveries, namely psr j0901-4046 and gleam-x j162759.5-523504.3 (hereafter gleam-x j1627), have corroborated an extant population of radio-loud periodic sources with long periods (76 and 1091 s, respectively) whose emission can hardly be explained by rotation losses. we argue that gleam-x j1627 is a highly... | evidence for an abundant old population of galactic ultra-long period magnetars and implications for fast radio bursts |
some repeating fast radio burst (frb) sources exhibit complex polarization behaviors, including frequency-dependent depolarization, variation of rotation measure (rm), and oscillating spectral structures of polarized components. very recently, feng et al. reported that active repeaters exhibit conspicuous frequency-dep... | temporal scattering, depolarization, and persistent radio emission from magnetized inhomogeneous environments near repeating fast radio burst sources |
in a search for short-time-scale astrophysical transients in time-domain data, radio-frequency interference (rfi) causes both large quantities of false positive candidates and a significant reduction in sensitivity if not correctly mitigated. here, we propose an algorithm that infers a time-variable frequency channel m... | iqrm: real-time adaptive rfi masking for radio transient and pulsar searches |
recent studies of fast radio bursts (frbs) have led to many theories associating them with young neutron stars. if this is the case, then the presence of supernova ejecta and stellar winds provides a changing dispersion measure (dm) and rotation measure (rm) that can potentially be probes of the environments of frb pro... | the dispersion and rotation measure of supernova remnants and magnetized stellar winds: application to fast radio bursts |
we present an overview and the first results from a large-scale pulsar timing programme that is part of the utmost project at the refurbished molonglo observatory synthesis radio telescope (most) near canberra, australia. we currently observe more than 400 mainly bright southern radio pulsars with up to daily cadences.... | the utmost pulsar timing programme i: overview and first results |
current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star’s outer crust is orders of magnitude larger than the dipole component inferred from spin-down measurements. this presents a serious challenge t... | magnetic field evolution in magnetar crusts through three-dimensional simulations |
neutron stars harbor extremely strong magnetic fields within their solid outer crust. the topology of this field strongly influences the surface temperature distribution and, hence, the star's observational properties. in this work, we present the first realistic simulations of the coupled crustal magnetothermal evolut... | three-dimensional modeling of the magnetothermal evolution of neutron stars: method and test cases |
solving field equations exactly in $f(r,t)-$ gravity is a challenging task. to do so, many authors have adopted different methods such as assuming both the metric functions and an equation of state (eos) and a metric function. however, such methods may not always lead to well-behaved solutions, and the solutions may ev... | exploring physical properties of compact stars in f(r,t)-gravity: an embedding approach |
we construct parameter sets of the relativistic mean-field model fitted to the recent constraints on the asymmetry energy j and the slope parameter l for pure neutron matter. we find cases of unphysical behavior, i.e., the appearance of negative pressures, for stiff parameter sets with low values of the effective mass ... | relativistic parameterizations of neutron matter and implications for neutron stars |
the recent detection of gravitational waves and electromagnetic counterparts from the double neutron star merger event gw+em170817 supports the standard paradigm of short gamma-ray bursts (sgrbs) and kilonovae/macronovae. it is important to reveal the nature of the compact remnant left after the merger, either a black ... | double neutron star mergers and short gamma-ray bursts: long-lasting high-energy signatures and remnant dichotomy |
mirror sectors have been proposed to address the problems of dark matter, baryogenesis, and the neutron lifetime anomaly. in this work we study a new, powerful probe of mirror neutrons: neutron star temperatures. when neutrons in the neutron star core convert to mirror neutrons during collisions, the vacancies left beh... | neutron star internal heating constraints on mirror matter |
we report the discovery of 13 new pulsars in the globular cluster ngc 1851 by the trapum large survey project using the meerkat radio telescope. the discoveries consist of six isolated millisecond pulsars (msps) and seven binary pulsars, of which six are msps and one is mildly recycled. for all the pulsars, we present ... | trapum discovery of 13 new pulsars in ngc 1851 using meerkat |
pulsar polarization profiles form a very basic database for understanding the emission processes in a pulsar magnetosphere. after careful polarization calibration of the 19-beam l-band receiver and verification of beam-offset observation results, we obtain polarization profiles of 682 pulsars from observations by the f... | fast pulsar database. i. polarization profiles of 682 pulsars |
the recent observation of the object hess j1731-347 suggests the existence of a very light and very compact neutron star, which is a challenge for commonly used equations of state for dense matter. in this work we present a relativistic mean-field model enriched with isovector and isoscalar meson crossing terms. these ... | relativistic mean-field model for the ultracompact low-mass neutron star hess j1731-347 |
the most energetic neutron stars, powered by their rotation, are capable of producing pulsed radiation from the radio up to γ rays with nearly tev energies. these pulsars are part of the universe of energetic and powerful particle accelerators, using their uniquely fast rotation and formidable magnetic fields to accele... | gamma-ray pulsars: a gold mine |
calculations of the effects of band structure on the neutron superfluid density in the crust of neutron stars made under the assumption that the effects of pairing are small [n. chamel, phys. rev. c 85, 035801 (2012)] lead to moments of inertia of superfluid neutrons so small that the crust alone is insufficient to acc... | superfluid density of neutrons in the inner crust of neutron stars: new life for pulsar glitch models |
we present the galactic merger rate for double neutron star (dns) binaries using an observed sample of eight dns systems merging within a hubble time. this sample includes the recently discovered, highly relativistic dns systems j1757-1854 and j1946+2052, and is approximately three times the sample size used in previou... | future prospects for ground-based gravitational-wave detectors: the galactic double neutron star merger rate revisited |
we report 21-year timing of one of the most precise pulsars: psr j1713+0747. its pulse times of arrival are well modeled by a comprehensive pulsar binary model including its three-dimensional orbit and a noise model that incorporates short- and long-timescale correlated noise such as jitter and red noise. its timing re... | testing theories of gravitation using 21-year timing of pulsar binary j1713+0747 |
in this paper, we have introduced a new f(r) gravity model as an attempt to have a model with more parametric control, so that the model can be used to explain the existing problems as well as to explore new directions in physics of gravity, by properly constraining it with recent observational data. here basic aim is ... | a new f(r) gravity model and properties of gravitational waves in it |
a few years after its discovery as a magnetar, sgr j1935+2154 started a new burst-active phase on 2020 april 27, accompanied by a large enhancement of its x-ray persistent emission. radio single bursts were detected during this activation, strengthening the connection between magnetars and fast radio bursts. we report ... | the x-ray reactivation of the radio bursting magnetar sgr j1935+2154 |
improving survey specifications are causing an exponential rise in pulsar candidate numbers and data volumes. we study the candidate filters used to mitigate these problems during the past fifty years. we find that some existing methods such as applying constraints on the total number of candidates collected per observ... | fifty years of pulsar candidate selection: from simple filters to a new principled real-time classification approach |
the molonglo observatory synthesis telescope (most) is an 18000 m2 radio telescope located 40 km from canberra, australia. its operating band (820-851 mhz) is partly allocated to telecommunications, making radio astronomy challenging. we describe how the deployment of new digital receivers, field programmable gate arra... | the utmost: a hybrid digital signal processor transforms the molonglo observatory synthesis telescope |
aims: we demonstrate the high multiplex advantage of crowded field 3d spectroscopy with the new integral field spectrograph muse by means of a spectroscopic analysis of more than 12 000 individual stars in the globular cluster ngc 6397.methods: the stars are deblended with a point spread function fitting technique, usi... | muse crowded field 3d spectroscopy of over 12 000 stars in the globular cluster ngc 6397. i. the first comprehensive hrd of a globular cluster |
we study current bounds on strong first-order phase transitions (pts) along the equation of state (eos) of dense strongly interacting matter in neutron stars, under the simplifying assumption that on either side of the pt, the eos can be approximated by a simple polytropic form. we construct a large ensemble of possibl... | constraints on strong phase transitions in neutron stars |
it is a well-known fact that compact gravitating objects admit bound state configurations for massive bosonic fields. in this work we describe a new class of superradiant instabilities of axion bound states in neutron star magnetospheres. the instability arises from the mixing of axion and photon modes in the magnetic ... | axion superradiance in rotating neutron stars |
the measurement of ultra-high energy (uhe) neutrinos (e > 1016 ev) opens a new field of astronomy with the potential to reveal the sources of ultra-high energy cosmic rays especially if combined with observations in the electromagnetic spectrum and gravitational waves. the arianna pilot detector explores the detecti... | targeting ultra-high energy neutrinos with the arianna experiment |
light axionic dark matter, motivated by string theory, is increasingly favored for the "no-wimp era". galaxy formation is suppressed below a jeans scale, of ≃ 10^8 m_⊙ by setting the axion mass to, m_b ∼ 10^{-22}ev, and the large dark cores of dwarf galaxies are explained as solitons on the de-broglie scale. this is pe... | recognising axionic dark matter by compton and de-broglie scale modulation of pulsar timing |
psr j1023+0038 is the first millisecond pulsar discovered to pulsate in the visible band; such a detection took place when the pulsar was surrounded by an accretion disk and also showed x-ray pulsations. we report on the first high time resolution observational campaign of this transitional pulsar in the disk state, us... | pulsating in unison at optical and x-ray energies: simultaneous high time resolution observations of the transitional millisecond pulsar psr j1023+0038 |
context. a precise understanding of the equation of state (eos) of dense and hot matter is key to modeling relativistic astrophysical environments, including core-collapse supernovae (ccsne), protoneutron star (pnss) evolution, and compact binary mergers.aims: in this paper, we extend the microscopic zero-temperature b... | microscopic equation of state of hot nuclear matter for numerical relativity simulations |
the magnetar swift j1818.0-1607 was discovered in 2020 march when swift detected a 9 ms hard x-ray burst and a long-lived outburst. prompt x-ray observations revealed a spin period of 1.36 s, soon confirmed by the discovery of radio pulsations. we report here on the analysis of the swift burst and follow-up x-ray and r... | a very young radio-loud magnetar |
we present an analytical solution of a highly magnetized jet/wind flow. the left side of the general force-free jet/wind equation (the "pulsar" equation) is separated into a rotating and a nonrotating term. the two equations with either term can be solved analytically, and the two solutions match each other very well. ... | analytical solution of magnetically dominated astrophysical jets and winds: jet launching, acceleration, and collimation |
many near-term quantum computing algorithms are conceived as variational quantum algorithms, in which parameterized quantum circuits are optimized in a hybrid quantum-classical setup. examples are variational quantum eigensolvers, quantum approximate optimization algorithms as well as various algorithms in the context ... | single-component gradient rules for variational quantum algorithms |
the distribution of the dark matter (dm) in dm-admixed neutron stars (danss) is supposed to result in either a dense dark core or an extended dark halo, subject to the dm fraction of the dans (fχ ) and the dm properties, such as the mass (mχ ) and the strength of the self-interaction (y). in this paper, we perform an i... | dark matter admixed neutron star properties in the light of x-ray pulse profile observations |
spider pulsars are millisecond pulsars in short-period (≲12-h) orbits with low-mass (~0.01-0.4 m⊙) companion stars. the pulsars ablate plasma from the companion star, causing time delays and eclipses of the radio emission from the pulsar. the magnetic field of the companion has been proposed to strongly influence both ... | a highly magnetized environment in a pulsar binary system |
high sensitivity radio searches of unassociated γ-ray sources have proven to be an effective way of finding new pulsars. using the five-hundred-meter aperture spherical radio telescope (fast) during its commissioning phase, we have carried out a number of targeted deep searches of fermi large area telescope (lat) γ-ray... | fast discovery of an extremely radio-faint millisecond pulsar from the fermi-lat unassociated source 3fgl j0318.1+0252 |
we analyse the stochastic properties of the 49 pulsars that comprise the first international pulsar timing array (ipta) data release. we use bayesian methodology, performing model selection to determine the optimal description of the stochastic signals present in each pulsar. in addition to spin-noise and dispersion-me... | from spin noise to systematics: stochastic processes in the first international pulsar timing array data release |
aims: we present the results of the monitoring programmes performed with the swift/xrt telescope and aimed specifically to detect an abrupt decrease of the observed flux associated with a transition to the propeller regime in two well-known x-ray pulsars 4u 0115+63 and v 0332+53.methods: both sources form binary system... | propeller effect in two brightest transient x-ray pulsars: 4u 0115+63 and v 0332+53 |
the diffuse very high-energy (vhe; >100 gev) γ-ray emission observed in the central 200 pc of the milky way by h.e.s.s. was found to follow dense matter distribution in the central molecular zone (cmz) up to a longitudinal distance of about 130 pc to the galactic centre (gc), where the flux rapidly decreases. this w... | characterising the vhe diffuse emission in the central 200 parsecs of our galaxy with h.e.s.s. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.