The behaviour of the nuclear symmetry energy near saturation density is important for our understanding of dense nuclear matter. This density dependence can be parameterised by the nuclear symmetry energy and its derivatives evaluated at nuclear saturation density. In this work we show that the core-crust interface mode of a neutron star is sensitive to these parameters, through the (density-weighted) shear-speed within the crust, which is in turn dependent on the symmetry energy profile of dense matter. We calculate the frequency at which the neutron star quadrupole ($\ell = 2$) crust-core interface mode must be driven by the tidal field of its binary partner to trigger a Resonant Shattering Flare (RSF). We demonstrate that coincident multimessenger timing of an RSF and gravitational wave chirp from a neutron star merger would enable us to place constraints on the symmetry energy parameters that are competitive with those from current nuclear experiments.
Much effort is devoted to measuring the nuclear symmetry energy through neutron star (NS) and nuclear observables. Since matter in the NS core may be non-hadronic, observables like radii and tidal deformability may not provide reliable constraints on properties of nucleonic matter. We demonstrate that coincident timing of a resonant shattering flare (RSF) and gravitational wave signal during binary NS inspiral probes the crust-core transition region and provides constraints on the symmetry energy comparable to terrestrial nuclear experiments. We show that nuclear masses, RSFs and measurements …
We demonstrate that resonant shattering flares can occur during close passages of neutron stars in eccentric or hyperbolic encounters. We provide updated estimates for the rate of close encounters of compact objects in dense stellar environments, which we find are substantially lower than given in previous works. While such occurrences are rare, we show that shattering flares can provide a strong electromagnetic counterpart to the gravitational wave bursts expected from such encounters, allowing triggered searches for these events to occur.
GRB 211211A was accompanied by a kilonova, implying a merger origin for the event. A precursor flare, modulated by quasi-periodic oscillations at $\approx 22\, \mbox{Hz}$, was also seen $\approx 1\, \mbox{s}$ prior to the main emission. It is suggested here that the precursor resulted from the resonant shattering of one star's crust prior to coalescence. Seismic aftershocks and low-frequency torsional modes may emanate from the rupture site in this case, explaining the underlying oscillations. This interpretation is directly analogous to proposals for giant flares from soft gamma repeaters, wh…
We treat prospects for multimessenger astronomy with giant flares (GFs), a rare transient event featured by magnetars that can be as luminous as a hundred of the brightest supernovae ever observed. The beamed photons could correlate with an axion counterpart via resonant conversion in the magnetosphere. In a realistic parameter space, we find that the sensitivity limit to galactic GFs for currently viable experiments is $\mathrm{g}_{ϕγ}\!\gtrsim\!\mathrm{several}\!\times\!10^{-13}$ GeV$^{-1}$ \& $\mathrm{g}_{ϕe}\!\gtrsim\!\mathrm{few}\!\times\!10^{-12}$. We rule out the compatibility of axion …
Resonant Shattering flares (RSFs) are bursts of gamma-rays expected to be triggered by tidal resonance of a neutron star (NS) during binary inspiral. They are strongly dependent on the magnetic field strength at the surface of the NS. By modelling these flares as being the result of multiple colliding relativistic shells launched during the resonance window, we find that the prompt non-thermal gamma-ray emission may have luminosity up to a few $\times10^{48}\text{ erg/s}$, and that a broad-band afterglow could be produced. We compute the expected rates of detectable RSFs using the BPASS popula…
The origin of magnetic fields in the universe is an open problem. Seed magnetic fields possibly produced in early times may have survived up to the present day close to their original form, providing an untapped window to the primeval universe. The recent observations of high-energy neutrinos from the blazar TXS 0506+056 in association with an electromagnetic counterpart in a broad range of wavelengths can be used to probe intergalactic magnetic fields via the time delay between the neutrinos and gamma rays as well as the time dependence of the gamma-ray fluxes. Using extensive three-dimension…
We draw the multimessenger picture of J1048+7143, a flat-spectrum radio quasar known to show quasi-periodic oscillations in the $γ$-ray regime. We generate the adaptively-binned Fermi Large Area Telescope light curve of this source above 168 MeV to find three major $γ$-ray flares of the source, such that all three flares consist of two-two sharp sub-flares. Based on radio interferometric imaging data taken with the Very Large Array, we find that the kpc-scale jet is directed towards west, while our analysis of $8.6$-GHz very long baseline interferometry data, mostly taken with the Very Long Ba…
The detection of the high-energy ($\sim290$ TeV) neutrino coincident with the flaring blazar TXS 0506+056, the first and only $3σ$ neutrino-source association to date, provides new, multimessenger tests of the weak equivalence principle (WEP) and Lorentz invariance. Assuming that the flight time difference between the TeV neutrino and gamma-ray photons from the blazar flare is mainly caused by the gravitational potential of the Laniakea supercluster of galaxies, we show that the deviation from the WEP for neutrinos and photons is conservatively constrained to have an accuracy of $10^{-6}-10^{-…
Upstream neutrino production and delayed jet emission in the blazar GB6 J1542+6129
ELTE（匈牙利罗兰大学）；Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences（孔科利天文台，HUN-REN 天文学与地球科学研究中心）；CSFK, MTA Centre of Excellence（CSFK，MTA 卓越中心）；Ruhr University Bochum（波鸿鲁尔大学）；University of Florida（佛罗里达大学）；University of Szeged（塞格德大学）；Chalmers University of Technology（查尔姆斯理工大学）；Max Planck Institute for Radio Astronomy（马克斯·普朗克射电天文研究所）；University of Alabama（阿拉巴马大学）
The origin of magnetic fields in the Universe is an open problem. Seed magnetic fields possibly produced in early times may have survived up to the present day close to their original form, providing an untapped window to the primeval Universe. The recent observations of high-energy neutrinos from the blazar TXS 0506+056 in association with an electromagnetic counterpart in a broad range of wavelengths can be used to probe intrinsic properties of this object and the traversed medium. Here we show that intergalactic magnetic fields (IGMFs) can affect the intrinsic spectral properties of this ob…
For the first time since the discovery of high-energy cosmic neutrinos by IceCube, a multimessenger campaign identified a distant gamma ray blazar, TXS 0506+056, as the source of a high-energy neutrino. The extraordinary brightness of the blazar despite its distance suggests that it may belong to a special class of sources that produce cosmic rays. Moreover, over the last 10 years of data, the high-energy neutrino flux from the source is dominated by a previous neutrino flare in 2014, which implies that flaring sources strongly contribute to the cosmic ray flux. We investigate the contribution…
After the successful detection of cosmic high-energy neutrinos, the field of multiwavelength photon studies of active galactic nuclei (AGN) is entering an exciting new phase. The first hint of a possible neutrino signal from the blazar TXS 0506+056 leads to the anticipation that AGN could soon be identified as point sources of high-energy neutrino radiation, representing another messenger signature besides the well-established photon signature. To understand the complex flaring behavior at multiwavelengths, a genuine theoretical understanding needs to be developed. These observations of the el…
We report on the radio brightening of the blazar TXS 0506+056 (at $z=0.3365$), supporting its identification as source of the high-energy (HE) neutrino IC-170922A by the IceCube Neutrino Observatory. MOJAVE/VLBA data indicate its radio brightness abruptly increasing since January 2016. When decomposing the total radio flux density curve (January 2008 - July 2018) provided by the Owens Valley Radio Observatory into eight Gaussian flares, the peak time of the largest flare overlaps with the HE neutrino detection, while the total flux density exhibits a threefold increase since January 2016. We r…
Fast Radio Bursts from Monster Shocks and Flares of Inspiraling Binary Neutron Stars: A Kinetic Model for Double Pulsar
Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；University of Potsdam（波茨坦大学）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；Max Planck Institute for Gravitational Physics (Albert Einstein Institute)（马克斯·普朗克引力物理学研究所（爱因斯坦研究所））；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学、法国国家科学研究中心、天体物理学与行星学研究所）
Measuring radii of merging neutron stars with interface-mode asteroseismology informed by nuclear theory and experiment
University of Bath（巴斯大学）；East Texas A&M University（东德克萨斯农工大学）；Texas A&M University（德克萨斯农工大学）；Ohio University（俄亥俄大学）；Michigan State University（密歇根州立大学）；CNRS（法国国家科学研究中心）
The Multimessenger discovery of the merger of two neutron stars on August 17, 2017, GW170817 / GRB170817A, accompanied by a gamma-ray burst and an optical kilonova, is a triumph of the ideas about the evolution of the baryon component in the Universe. Despite the current uniqueness of this observation, the obtained variety of experimental data makes it possible right now to draw important theoretical conclusions about the origin of the double neutron star, their merger, and the subsequent flare-up of the electromagnetic radiation. We present that the discovery of the merger at a distance of 40…
A number of observed phenomena associated with individual neutron star systems or neutron star populations find explanations in models in which the neutron star crust plays an important role. We review recent work examining the sensitivity to the slope of the symmetry energy $L$ of such models, and constraints extracted on $L$ from confronting them with observations. We focus on six sets of observations and proposed explanations: (i) The cooling rate of the neutron star in Cassiopeia A, confronting cooling models which include enhanced cooling in the nuclear pasta regions of the inner crust, (…
