Latest in astro-ph.he

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Novel Techniques for Constraining Neutron-Capture Rates Relevant for r-Process Heavy-Element NucleosynthesisApr 22 2019The rapid-neutron capture process ($r$ process) is identified as the producer of about 50\% of elements heavier than iron. This process requires an astrophysical environment with an extremely high neutron flux over a short amount of time ($\sim$ seconds), ... More
Chandra, MDM, Swift, and NuSTAR observations confirming the SFXT nature of AX J1949.8+2534Apr 22 2019AX J1949.8+2534 is a candidate supergiant fast X-ray transient (SFXT) observed in outburst by INTEGRAL (IGR J19498+2534). We report on the results of six Neil Gehrels Swift-XRT, one Chandra, and one NuSTAR observation of the source. We find evidence of ... More
Fast orbital shrinkage of black hole X-ray binaries driven by circumbinary disksApr 22 2019Recently, the black hole X-ray binary (BHXB) Nova Muscae 1991 has been reported to be experiencing an extremely rapid orbital decay. So far, three BHXBs have anomalously high orbital period derivatives, which can not be interpreted by the standard stellar ... More
TiK-means: $K$-means clustering for skewed groupsApr 21 2019The $K$-means algorithm is extended to allow for partitioning of skewed groups. Our algorithm is called TiK-Means and contributes a $K$-means type algorithm that assigns observations to groups while estimating their skewness-transformation parameters. ... More
Can Luminous, Rapidly Evolving Optical Transients be Explained by the Magnetar-powered Stripped Core-Collapse Supernova Model?Apr 21 2019Over the past decade, many rapidly evolving optical transients (REOTs), whose rise and decline timescales are significantly shorter than those of canonical supernovae (SNe), have been discovered and studied. Some REOTs have high peak luminosity ($\gtrsim ... More
The Stellar CME-flare relation: What do historic observations reveal?Apr 21 2019Solar CMEs and flares have a statistically well defined relation, with more energetic X-ray flares corresponding to faster and more massive CMEs. How this relation extends to more magnetically active stars is a subject of open research. Here, we study ... More
A statistical method to detect non-stationarities of gamma-ray burst jetsApr 20 2019We propose a method to detect possible non-stationarities of gamma-ray burst jets. Assuming that the dominant source of variability in the prompt gamma light curve is the non-stationarity of the jet, we show that there should be a connection between the ... More
GeV-TeV Cosmic Ray Leptons in the Solar System from the Bow Shock Wind Nebula of the Nearest Millisecond Pulsar J0437-4715Apr 20 2019We consider acceleration of leptons up to GeV-TeV energies in the bow shock wind nebula of PSR J0437-4715 and their subsequent diffusion through the interstellar magnetic fields. The leptons accelerated at the pulsar wind termination surface are injected ... More
A Search for Pulsed Very High-Energy Gamma Rays from Thirteen Young Pulsars in Archival VERITAS DataApr 19 2019We conduct a search for periodic emission in the very high-energy gamma-ray band (VHE; E > 100 GeV) from a total of 13 pulsars in an archival VERITAS data set with a total exposure of over 450 hours. The set of pulsars includes many of the brightest young ... More
Disentangling nature from nurture: tracing the origin of seed black holesApr 19 2019The origin and properties of black hole seeds that grow to produce the detected population of supermassive black holes are unconstrained at present. Despite the existence of several potentially feasible channels for the production of initial seeds in ... More
Astro2020 Science White Paper: Using X-Ray Polarimetry to Probe the Physics of Black Holes and Neutron StarsApr 19 2019This white paper highlights compact object and fundamental physics science opportunities afforded by high-throughput broadband (0.1-60 keV) X-ray polarization observations. X-ray polarimetry gives new observables with geometric information about stellar ... More
DarkHistory: A code package for calculating modified cosmic ionization and thermal histories with dark matter and other exotic energy injectionsApr 19 2019We present a new public Python package, DarkHistory, for computing the effects of dark matter annihilation and decay on the temperature and ionization history of the early universe. DarkHistory simultaneously solves for the evolution of the free electron ... More
Characterization of numerical relativity waveforms of eccentric binary black hole mergersApr 19 2019We introduce a method to quantify the initial eccentricity, gravitational wave frequency, and mean anomaly of numerical relativity simulations that describe non-spinning black holes on moderately eccentric orbits. We demonstrate that this method provides ... More
Discovery and Early Evolution of ASASSN-19bt, the First TDE Detected by TESSApr 19 2019We present the discovery and early evolution of ASASSN-19bt, a tidal disruption event (TDE) discovered by the All-Sky Automated Survey for Supernovae at a distance of $d\simeq115$ Mpc and the first TDE to be detected by TESS. As the TDE is located in ... More
Effects of winds on the leftover hydrogen in massive stars following Roche-lobe overflowApr 19 2019We find that applying a theoretical wind mass-loss rate from Monte Carlo radiative transfer models for hydrogen-deficient stars results in significantly more leftover hydrogen following stable mass transfer through Roche-lobe overflow than when we use ... More
Non-thermal X-rays from Colliding Wind Shock Acceleration in the Massive Binary Eta CarinaeApr 19 2019Cosmic-ray acceleration has been a long-standing mystery and despite more than a century of study, we still do not have a complete census of acceleration mechanisms. The collision of strong stellar winds in massive binary systems creates powerful shocks, ... More
The expectation of cosmic ray proton and helium energy spectrum below 4 PeV measured by LHAASOApr 19 2019Large High Altitude Air Shower Observatory(LHAASO) is a composite cosmic ray observatory consisting of three detector arrays: kilometer square array (KM2A) which includes the electromagnetic detector array and muon detector array, water Cherenkov detector ... More
Long-term spectral study of the black hole Cygnus X-1 using INTEGRALApr 19 2019We utilize the joint capabilities of IBIS and SPI to perform a state-resolved 20--2000\,keV analysis of the microquasar Cygnus X-1. In both LHS and HSS, the spectral analysis reveals the presence of a high-energy tail above 400\,keV in addition to a standard, ... More
Cosmic-ray transport from AMS-02 B/C data: benchmark models and interpretationApr 18 2019This article aims at establishing new benchmark scenarios for Galactic cosmic-ray propagation in the GV-TV rigidity range, based on fits to the AMS-02 B/C data with the USINE v3.5 propagation code. We employ a new fitting procedure, cautiously taking ... More
Constraining the equation of state of high-density cold matter using nuclear and astronomical measurementsApr 18 2019The increasing richness of data related to cold dense matter, from laboratory experiments to neutron star observations, requires a framework for constraining the properties of such matter that makes use of all relevant information. Here we present a rigorous ... More
Nonlinear flavor development of a two-dimensional neutrino gasApr 18 2019We present a numerical survey of the nonlinear flavor development of dense neutrino gases. This study is based on the stationary, two-dimensional ($x$ and $z$), two-beam, monochromatic neutrino line model with a periodic boundary condition along the $x$ ... More
Structured jets and X-ray plateaus in Gamma-ray BurstsApr 18 2019The first multi-messenger detection of a binary system of neutron stars, GW170817, brought to the forefront the structured jet model as a way to explain multi-wavelength observations taken over one year. Here we show that high-latitude emission (HLE) ... More
Convolutional neural networks: a magic bullet for gravitational-wave detection?Apr 18 2019In the last few years, machine learning techniques, in particular convolutional neural networks, have been investigated as a method to replace or complement traditional matched filtering techniques that are used to detect the gravitational-wave signature ... More
Uncovering Red and Dusty Ultraluminous X-ray Sources with SpitzerApr 18 2019We present a mid-infrared (IR) sample study of nearby ultraluminous X-ray sources (ULXs) using multi-epoch observations with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. Spitzer/IRAC observations taken after 2014 were obtained as part ... More
Particle Energy Diffusion in Linear Magnetohydrodynamic WavesApr 18 2019In high-energy astronomical phenomena, the stochastic particle acceleration by turbulences is one of promising processes to generate non-thermal particles. In this paper, providing a temporally evolving wave ensemble, which consists of a single mode (Alfv\'en, ... More
The time-resolved spectra of photospheric emission from a structured jet for gamma-ray burstsApr 17 2019The quasi-thermal components found in many Fermi gamma-ray bursts (GRBs) imply that the photosphere emission indeed contributes to the prompt emission of many GRBs. But whether the observed spectra empirically fitted by the Band function or cutoff power ... More
Constraining the Delay Time Distribution of Binary Neutron Stars with the Host Galaxies of Gravitational Wave EventsApr 17 2019The delay time distribution of (DTD) of binary neutron stars (BNS) remains poorly constrained, mainly by the small known population of Galactic binaries, the properties of short gamma-ray burst host galaxies, and inferences from $r$-process enrichment. ... More
Dark Matter Strikes Back at the Galactic CenterApr 17 2019Statistical evidence has previously suggested that the Galactic Center GeV Excess (GCE) originates largely from point sources, and not from annihilating dark matter. We examine the impact of unmodeled source populations on identifying the true origin ... More
Towards an accurate description of an accretion induced collapse and the associated ejected massApr 17 2019We revisit the accretion induced collapse (AIC) process, in which a white dwarf collapses into a neutron star. We are motivated by the persistent radio source associated with the fast radio burst 121102, which was explained by Waxman (2017) as a weak ... More
Disc Tearing and Bardeen-Petterson Alignment in GRMHD Simulations of Highly Tilted Thin Accretion DiscsApr 17 2019Luminous active galactic nuclei (AGN) and X-Ray binaries (XRBs) tend to be surrounded by geometrically thin, radiatively cooled accretion discs. According to both theory and observations, these are -- in many cases -- highly misaligned with the black ... More
First detection of PSR B1259-63/LS 2883 in the Millimeter and Submillimeter Wavelengths with ALMAApr 17 2019We report Atacama Large Millimeter/submillimeter Array (ALMA) observations of the binary system containing the pulsar PSR B1259-63 orbiting around a Be star LS 2883 after the 2017 periastron passage. We detected radio continuum emission from the binary ... More
Jet-cocoon outflows from neutron star mergers: structure, light curves, and fundamental physicsApr 17 2019The discovery of GW170817, the merger of a binary neutron star (NS) triggered by a gravitational wave detection by LIGO and Virgo, has opened a new window of exploration in the physics of NSs and their cosmological role. Among the important quantities ... More
Interface effects of strange quark matterApr 17 2019The interface effects play important roles for the properties of strange quark matter (SQM) and the related physical processes. We show several examples on the implications of interface effects for both stable and unstable SQM. Based on an equivparticle ... More
Detection of Cosmic Rays from ground: an IntroductionApr 17 2019Cosmic rays are the most outstanding example of accelerated particles. They are about 1\% of the total mass of the Universe, so that cosmic rays would represent by far the most important energy transformation process of the Universe. Despite large progresses ... More
Axion superradiance in rotating neutron starsApr 17 2019It 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 ... More
Fitting B/C cosmic-ray data in the AMS-02 era: a cookbookApr 17 2019AMS-02 on the ISS has been releasing data of unprecedented accuracy. This poses new challenges for their interpretation. We refine the methodology to get a statistically sound determination of the cosmic-ray propagation parameters. We inspect the numerical ... More
Cosmic Ray ModelsApr 17 2019We review progress in high-energy cosmic ray physics focusing on recent experimental results and models developed for their interpretation. Emphasis is put on the propagation of charged cosmic rays, covering the whole range from $\sim (20-50)$\,GV, i.e.\ ... More
First Detection of Radio Linear Polarization of GRB AfterglowApr 17 2019We report the first detection of radio polarization of a GRB afterglow with the first intensive combined use of telescopes in the millimeter and submillimeter ranges for GRB171205A. The linear polarization degree in the millimeter band at the sub-percent ... More
Long-term Simulations of Multi-Dimensional Core-collapse Supernovae: Implications for Neutron Star KicksApr 17 2019Core-collapse supernovae (CCSNe) are the final stage of massive stars, marking the birth of neutron stars (NSs). The aspherical mass ejection drives a natal kick of the forming NS. In this work, we study the properties of the NS kick based on our long-term ... More
From the supernova to the supernova remnant: the three-dimensional imprint of a thermonuclear explosionApr 17 2019Recent progress in the three-dimensional modeling of supernovae (SN) has shown the importance of asymmetries for the explosion. This calls for a reconsideration of the modeling of the subsequent phase, the supernova remnant (SNR), which has commonly relied ... More
Testing the Kerr hypothesis using X-ray reflection spectroscopy with NuSTAR data of Cygnus X-1 in the soft stateApr 17 2019We continue exploring the constraining capabilities of X-ray reflection spectroscopy to test the Kerr-nature of astrophysical black holes and we present the results of our analysis of two NuSTAR observations of Cygnus X-1 in the soft state. We find that ... More
A line-binned treatment of opacities for the spectra and light curves from neutron star mergersApr 16 2019The electromagnetic observations of GW170817 were able to dramatically increase our understanding of neutron star mergers beyond what we learned from gravitational waves alone. These observations provided insight on all aspects of the merger from the ... More
A hierarchical test of general relativity with gravitational wavesApr 16 2019We propose a hierarchical approach to testing general relativity with multiple gravitational wave detections. Unlike existing strategies, our method does not assume that parameters quantifying deviations from general relativity are either common or completely ... More
Improved photomeson model for interactions of cosmic ray nucleiApr 16 2019Photon-hadronic interactions are important for the sources and the transport of Ultra-High Energy Cosmic Rays (UHECRs). Current state-of-the-art cosmic ray transport simulations handle nuclear disintegration at energies of the Giant Dipole Resonance at ... More
The Tail of PSR J0002+6216 and the Supernova Remnant CTB 1Apr 16 2019We have carried out VLA imaging and a Fermi timing analysis of the 115 ms gamma-ray and radio pulsar PSR J0002+6216. We found that the pulsar lies at the apex of a narrowly collimated cometary-like 7 arcmin tail of non-thermal radio emission which we ... More
Fast Radio BurstsApr 16 2019The discovery of radio pulsars over a half century ago was a seminal moment in astronomy. It demonstrated the existence of neutron stars, gave a powerful observational tool to study them, and has allowed us to probe strong gravity, dense matter, and the ... More
Measurement of the spin of the M87 black hole from its observed twisted lightApr 16 2019The warped spacetime around a black hole modifies the propagation of light and radio. A recent study predicted that light emitted from the immediate vicinity of a massive rotating black hole (BH) should be twisted, i.e. be imprinted with orbital angular ... More
Spontaneous ring formation in wind-emitting accretion discsApr 16 2019Rings and gaps have been observed in a wide range of protoplanetary discs, from young systems like HLTau to older discs like TW Hydra. Recent disc simulations have shown that magnetohydrodynamic (MHD) turbulence (in the ideal or non-ideal regime) can ... More
The Keplerian three-body encounter II. Comparisons with isolated encounters and impact on gravitational wave merger timescalesApr 16 2019We investigate the role of the Keplerian tidal field generated by a supermassive black hole (SMBH) on the three-body dynamics of stellar mass black holes. We consider two scenarios occurring close to the SMBH: the breakup of unstable triples and three-body ... More
The Keplerian three-body encounter II. Comparisons with isolated encounters and impact on gravitational wave merger timescalesApr 16 2019Apr 18 2019We investigate the role of the Keplerian tidal field generated by a supermassive black hole (SMBH) on the three-body dynamics of stellar mass black holes. We consider two scenarios occurring close to the SMBH: the breakup of unstable triples and three-body ... More
Constraining massive star activities in the final years through properties of supernovae and their progenitorsApr 16 2019Recent observations of supernovae (SNe) just after the explosion suggest that a good fraction of SNe have the confined circumstellar material (CSM) in the vicinity, and the pre-SN enhanced mass loss may be a common property. The physical mechanism of ... More
Covariant BSSN formulation in bimetric relativityApr 16 2019Numerical integration of the field equations in bimetric relativity is necessary to obtain solutions describing realistic systems. Thus, it is crucial to recast the equations into a well-posed form. In general relativity, under certain assumptions, the ... More
The X-ray binary GX 339-4/V821 Ara: the distance, inclination, evolutionary status and mass transferApr 16 2019We consider constraints on the distance, inclination and component masses in the X-ray binary GX 339--4 resulting from published works, and then construct detailed evolutionary models for the donor. From both considerations, we find that unless the compact ... More
Characteristics of Long Gamma-Ray bursts in the Comoving FrameApr 16 2019We compile a sample of 93 long gamma-ray bursts (GRBs) from Fermi satellite and 131 from Konus-Wind, which have measured redshifts and well determined spectra, and estimate their pseudo Lorentz factors (${\Gamma_0}$) using the tight ${L_{{\rm{iso}}}}$-${E_{\rm ... More
Signatures from a Cocoon and an off-axis material ejected in a merger of compact objects: An analytical approachApr 16 2019The production of both gravitational waves and short gamma-ray bursts (sGRBs) is widely associated with the merger of compact objects. Several studies have modelled the evolution of the electromagnetic emission using the synchrotron emission produced ... More
Search for multiwavelength emission from the binary millisecond pulsar PSR J1836-2354A in the globular cluster M22Apr 16 2019We present a multi-band search for X-ray, optical and $\gamma$-ray emission of the radio binary millisecond pulsar J1836-2354A, hosted in the globular cluster M22. X-ray emission is significantly detected in two Chandra observations, performed in 2005 ... More
Outflows in the Discs of Active GalaxiesApr 16 2019Recent advances in observations have provided a wealth of measurements of the expansions of outflows in galactic discs out to large radii in a variety of galactic hosts. To provide an updated baseline for the interpretation of such data, and to assess ... More
Detailed X-ray spectroscopy of the magnetar 1E 2259+586Apr 16 2019Magnetic field geometry is expected to play a fundamental role in magnetar activity. The discovery of a phase-variable absorption feature in the X-ray spectrum of SGR 0418+5729, interpreted as cyclotron resonant scattering, suggests the presence of very ... More
The rare extended radio-loud narrow-line Seyfert 1 galaxy SDSS J1030+5516 at high resolutionApr 16 2019Recently, Rakshit et al. (2018) reported the discovery of SDSS J103024.95$+$551622.7, a radio-loud narrow-line Seyfert 1 galaxy having a $\sim 100$ kpc scale double-lobed radio structure. Here we analyse archival radio interferometric imaging data taken ... More
Modelling the multi-wavelength emissions from PSR B1259-63/LS 2883: the effects of the stellar disc on shock radiationsApr 16 2019PSR B1259-63/LS 2883 is an elliptical pulsar/Be star binary and emits broadband emissions from radio to TeV $\gamma$-rays. The massive star possesses an equatorial disc, which is inclined with the orbital plane of the pulsar. The non-thermal emission ... More
Cooling of the Cassiopeia A neutron star and the effect of diffusive nuclear burningApr 16 2019The study of how neutron stars cool over time can provide invaluable insights into fundamental physics such as the nuclear equation of state and superconductivity and superfluidity. A critical relation in neutron star cooling is the one between observed ... More
A global view of the inner accretion/ejection flow around super massive black holes: radiation driven accretion disk winds in a physical contextApr 15 2019Understanding the physics and geometry of accretion and ejection around super massive black holes (SMBHs) is important to understand the evolution of active galactic nuclei (AGN) and therefore of the large scale structures of the Universe. We aim at providing ... More
Causation of Late Quaternary Rapid-increase Radiocarbon AnomaliesApr 15 2019Brief (less than 100 years) rapid-increase anomalies in the Earth's atmospheric radiocarbon production have previously been attributed to either gamma photon radiation from supernovae or to cosmic ray particle radiation from exceptionally large solar ... More
ALMA Detection of a Linearly Polarized Reverse Shock in GRB 190114CApr 15 2019We present ALMA 97.5 GHz total intensity and linear polarization observations of the mm-band afterglow of GRB 190114C spanning 2.2 to 5.2 hours after the burst. We detect linear polarization at the $\approx 5\,\sigma$ level, decreasing from $\Pi=(0.87\pm0.13)\%$ ... More
SN 2016iet: The Pulsational or Pair Instability Explosion of a Low Metallicity Massive CO Core Embedded in a Dense Hydrogen-Poor Circumstellar MediumApr 15 2019We present optical photometry and spectroscopy of SN 2016iet, an unprecedented Type I supernova (SN) at $z=0.0676$ with no obvious analog in the existing literature. The peculiar light curve has two roughly equal brightness peaks ($\approx -19$ mag) separated ... More
A Mechanism for Triple-Ridge Emission Structure of AGN JetsApr 15 2019Recent radio VLBI observations of the relativistic jet in M87 radio galaxy have shown a triple-ridge structure that consists of the conventional limb-brightened feature and a central narrow ridge. Motivated by these observations, we examine a steady axisymmetric ... More
High efficiency photospheric emission in gamma-ray burstsApr 15 2019The primary dissipation mechanism in jets of gamma-ray bursts (GRBs), and the high efficiency of the prompt emission are long standing issues. One possibility is strong collimation of a weakly magnetized relativistic jet by the surrounding medium, which ... More
Criteria for the occurrence of Crossings Between the Angular Distributions of Electron Neutrinos and Antineutrinos in the Supernova CoreApr 15 2019Neutrino fast pairwise conversions have been postulated to occur in the dense core of a core-collapse supernova (SN), possibly having dramatic consequences on the SN mechanism and the observable neutrino signal. One crucial condition favoring pairwise ... More
New Binary Black Hole Mergers in the Second Observing Run of Advanced LIGO and Advanced VirgoApr 15 2019We report the detection of new binary black hole merger events in the publicly available data from the second observing run of advanced LIGO and advanced Virgo (O2). The mergers were discovered using the new search pipeline described in Venumadhav et ... More
Time-delay between neutrinos and gamma-rays in short GRBsApr 15 2019In this work we make an estimate of the time-delay between signals, recorded at detectors on Earth, of neutrinos and photons originated in a short gamma-ray burst. We describe the geometry and dynamics of the system according to the Fireshell model. The ... More
Neutrino oscillations and decoherence in short-GRB progenitorsApr 15 2019Neutrinos are produced in cosmic accelerators, like active galactic nuclei (AGNs), blazars, supernova (SN) remnants and gamma-ray bursts (GRBs). On their way to the Earth they experience flavor-oscillations. The interactions of the neutrinos coming from ... More
Asymptotic safety casts its shadowApr 15 2019We set out to bridge the gap between regular black-hole spacetimes and observations of a black-hole shadow by the Event Horizon Telescope. We explore modifications of spinning and non-spinning black-hole spacetimes inspired by asymptotically safe quantum ... More
Inferring AGN jet parameters using Bayesian analysis of VLBI data with non-uniform jet modelApr 15 2019Physical parameters of AGN jets observed with Very Long Baseline Interferometry (VLBI) are usually inferred from the core shift measurements or flux and size measured at a peak frequency of the synchrotron spectrum. Both are preceded by modelling of the ... More
Probing the production of actinides under different r-process conditionsApr 15 2019Several extremely metal-poor stars are known to have an enhanced thorium abundance. These actinide-boost stars have likely inherited material from an r-process that operated under different conditions than the most frequent r-process in the galaxy. In ... More
Constraining the neutron star equation of state using Pulse Profile ModelingApr 15 2019One very promising technique for measuring the dense matter Equation of State exploits hotspots that form on the neutron star surface due to the pulsar mechanism, accretion streams, or during thermonuclear explosions in the neutron star ocean. This article ... More
Evolution of three-dimensional Relativistic Ion Weibel Instability: Competition with Kink InstabilityApr 15 2019In this paper, we report our recent findings on the relativistic Weibel instability and its nonlinear saturation by performing numerical simulations of collisionless plasmas. Analysis of the obtained numerical results revealed that the nonlinear phase ... More
Analysis and Modelling of the early multi-wavelength observations of the luminous GRB 190114CApr 15 2019Very-high-energy (VHE; $\geq 10$ GeV) photons are expected from the nearest and brightest Gamma-ray bursts (GRBs). These energetic photons could provide compelling evidence about the radiative processes, physical composition of the ejecta, emitting regions, ... More
Unveiling the origin of the gamma-ray emission in NGC 1068 with the Cherenkov Telescope ArrayApr 15 2019Several observations are revealing the widespread occurrence of mildly relativistic wide-angle AGN winds strongly interacting with the gas of their host galaxy. Such winds are potential cosmic-ray accelerators, as supported by gamma-ray observations of ... More
Unveiling the origin of the gamma-ray emission in NGC 1068 with the Cherenkov Telescope ArrayApr 15 2019Apr 17 2019Several observations are revealing the widespread occurrence of mildly relativistic wide-angle AGN winds strongly interacting with the gas of their host galaxy. Such winds are potential cosmic-ray accelerators, as supported by gamma-ray observations of ... More
Probing an X-ray flare pattern in Mrk 421 induced by multiple stationary shocks: a solution to the bulk Lorentz factor crisisApr 15 2019The common observations of multiple radio VLBI stationary knots in high-frequency-peaked BL Lacs (HBLs) can be interpreted as multiple recollimation shocks accelerating particles along jets. This approach can resolve the so-called "bulk Lorentz factor ... More
The First Day in the Life of a Magnetar: Evolution of the Inclination Angle, Magnetic Dipole Moment and Braking Index of Millisecond Magnetars During Gamma-Ray Burst AfterglowsApr 14 2019The afterglow light curves of some gamma-ray bursts (GRBs) show a shallow decay (plateau) phase implying continuous injection of energy. The source of this energy is very commonly assumed to be the spin-down power of a nascent millisecond magnetar. The ... More
Mechanism of the Changing Look phenomenon in Active Galactic NucleiApr 14 2019Changing-look phenomenon observed now in a growing number of active galaxies challenges our understanding of the accretion process close to a black hole. We propose a simple explanation for periodic outbursts in sources operating at a few per cent of ... More
A very massive neutron star: relativistic Shapiro delay measurements of PSR J0740+6620Apr 14 2019Despite its importance to our understanding of physics at supranuclear densities, the equation of state (EoS) of matter deep within neutron stars remains poorly understood. Millisecond pulsars (MSPs) are among the most useful astrophysical objects in ... More
Astro2020 Science White Paper: A Unification of the Micro and Macro Physics in the Intracluster Medium of Nearby ClustersApr 14 2019Clusters of galaxies are the most massive virialized structures in the Universe. The microphysical properties of the intracluster plasma can affect dynamical processes over an enormous range: from the feedback of active galactic nuclei to shock acceleration ... More
Constraining the duty cycle of transient low-mass X-ray binaries through simulationsApr 14 2019We report the results of the application of the simulation method used in Carbone et al. (2017) to a large number of observations obtained using the Swift X-ray telescope on several Galactic globular clusters. We calculated the ratio between the duty ... More
X-ray transient CDF-S XT2: the electromagnetic and gravitational-wave radiations of a supra-massive neutron starApr 14 2019The merging process of binary neutron stars is the source of the quadrupole gravitational-wave (GW) radiation. Its remnant can be either a supra-massive or a stable NS. Such evidence of magnetar signature has been supported indirectly by observed X-ray ... More
High-Resolution X-ray Imaging Studies of Neutron Stars, Pulsar Wind Nebulae and Supernova RemnantsApr 13 2019Supernova remnants serve as nearby laboratories relevant to many areas in Astrophysics, from stellar and galaxy evolution to extreme astrophysics and the formation of the heavy elements in the Universe. The Chandra X-ray mission has enabled a giant leap ... More
Modeling the Light Curves of the Luminous Type Ic Supernova 2007DApr 13 2019SN~2007D is a nearby (redshift $z = 0.023146$), luminous Type Ic supernova (SN) having a narrow light curve (LC) and high peak luminosity. Previous research based on the assumption that it was powered by the $^{56}$Ni cascade decay suggested that the ... More
Supernova 2018aoq and a distance to Seyfert galaxy NGC 4151Apr 13 2019We present optical photometric observations of SN 2018aoq from 2 to 100 days after explosion, and 7 spectra at epochs from 11 to 71 days. The light curves and spectra are typical for SNe II-P. As previously reported, SN 2018aoq appears to be of intermediate ... More
What can PSR J1640-4631 tell us about the internal physics of this neutron star?Apr 13 2019Gravitational wave emissions (GWEs) of pulsars could not only make them promising targets for continuous gravitational wave searches but also leave imprints in their timing data. We interpret the measured braking index of PSR J1640-4631 with a model involving ... More
Murchison Widefield Array and XMM-Newton observations of the Galactic supernova remnant G5.9+3.1Apr 13 2019In this paper we discuss the radio continuum and X-ray properties of the so-far poorly studied Galactic supernova remnant (SNR) G5.9+3.1. We present the radio spectral energy distribution (SED) of the Galactic SNR G5.9+3.1 obtained with the Murchison ... More
Investigating the origin of the Fe emission lines of the Seyfert 1 galaxy Mrk~205Apr 13 2019We have investigated the nature and origin of the Fe K emission lines in Mrk~205 using observations with {\it Suzaku} and {\it XMM-Newton}, aiming to resolve the ambiguity between a broad emission line and multiple unresolved lines of higher ionization. ... More
A Search for Cosmic Neutrino and Gamma-Ray Emitting Transients in 7.3 Years of ANTARES and Fermi LAT DataApr 12 2019We analyze 7.3 years of ANTARES high-energy neutrino and Fermi LAT {\gamma}-ray data in search of cosmic neutrino + {\gamma}-ray ({\nu}+{\gamma}) transient sources or source populations. Our analysis has the potential to detect either individual {\nu}+{\gamma} ... More
Type Ib supernova Master OT J120451.50+265946.6: radio emitting shock with inhomogeneities crossing through a dense shellApr 12 2019We present radio observations of a Type Ib supernova (SN) Master OT J120451.50+265946.6. Our low frequency Giant Metrewave Radio Telescope (GMRT) data taken when the SN was in the optically thick phase for observed frequencies reveal inhomogeneities in ... More
Constraints on the Blazar Contribution to the Cumulative High-Energy Neutrino IntensityApr 12 2019We investigate the blazar contribution to the cumulative neutrino intensity assuming a generic relationship between neutrino and gamma-ray luminosities, $\log (L_{\nu})\propto \log(L_{\rm ph})$. Using the gamma-ray luminosity functions for blazars including ... More
Complementarity of Stacking and Multiplet Constraints on the Blazar Contribution to the Cumulative High-Energy Neutrino IntensityApr 12 2019Apr 17 2019We investigate the blazar contribution to the cumulative neutrino intensity assuming a generic relationship between neutrino and gamma-ray luminosities, $\log (L_{\nu})\propto \log(L_{\rm ph})$. Using the gamma-ray luminosity functions for blazars including ... More
Tracking the footprints of the radio pulsar B1727$-$47: proper motion, host supernova remnant, and the glitchesApr 12 2019The bright radio pulsar B1727$-$47 with a characteristic age of 80 kyr is among the first pulsars discovered 50 yr ago. Using its regular timing observations and interferometric positions at three epochs, we measured, for the first time, the pulsar proper ... More
A Bayesian Analysis of SDSS J0914+0853, a Low-Mass Dual AGN CandidateApr 12 2019We present the first results from BAYMAX (Bayesian AnalYsis of Multiple AGN in X-rays), a tool that uses a Bayesian framework to quantitatively evaluate whether a given Chandra observation is more likely a single or dual point source. Although the most ... More
Asymmetries of Heavy Elements in the Young Supernova Remnant Cassiopeia AApr 12 2019Supernova remnants (SNRs) offer the means to study supernovae (SNe) long after the original explosion and can provide a unique insight into the mechanism that governs these energetic events. In this work, we examine the X-ray morphologies of different ... More
Tidal Disruptions of Stars by Black Hole Remnants in Dense Star ClustersApr 12 2019In a dense stellar environment, such as the core of a globular cluster (GC), dynamical interactions with black holes (BHs) are expected to lead to a variety of astrophysical transients. Here we explore tidal disruption events (TDEs) of stars by stellar-mass ... More