Latest in astro-ph.he

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Type IIn supernova light-curve properties measured from an untargeted survey sampleJun 13 2019We present a sample of supernovae Type IIn (SNe IIn) from the untargeted, magnitude-limited surveys of the Palomar Transient Factory (PTF) and its successor, iPTF. SNe IIn found and followed by the PTF/iPTF were used to select a sample of 42 events with ... More
Warm Absorber Diagnostics of AGN DynamicsJun 13 2019Warm absorbers and related phenomena are one of the observable manifestations of outflows or winds from active galactic nuclei (AGN). Warm absorbers are common in low luminosity AGN, they have been extensively studied observationally, and are well described ... More
First Detection of Photons with Energy Beyond 100 TeV from an Astrophysical SourceJun 13 2019We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of muon number measured in an air shower, we successfully suppress ... More
Do Delta Baryons Play a Role in Neutron Stars?Jun 13 2019The presence of exotic hadrons, such as hyperons and $\Delta$ isobars, in the dense nuclear matter in their cores has been shown to produce important changes in the properties of neutron stars. Within the quark-meson coupling model, we show that the many-body ... More
Eikonal quasinormal modes of black holes beyond General RelativityJun 13 2019Much of our physical intuition about black hole quasinormal modes in General Relativity comes from the eikonal/geometric optics approximation. According to the well-established eikonal model, the fundamental quasinormal mode represents wavepackets orbiting ... More
A rapidly-changing jet orientation in the stellar-mass black hole V404 CygniJun 12 2019Powerful relativistic jets are one of the main ways in which accreting black holes provide kinetic feedback to their surroundings. Jets launched from or redirected by the accretion flow that powers them should be affected by the dynamics of the flow, ... More
The Orbital Lense-Thirring Precession in a Strong FieldJun 12 2019We study the exact evolution of the orbital angular momentum of a massive particle in the gravitational field of a Kerr black hole. We show analytically that, for a wide class of orbits, the angular momentum's hodograph is always close to a circle. This ... More
Binary neutron star mergers: effects of spin and post-merger dynamicsJun 12 2019Spin can have significant effects on the electromagnetic transients accompanying binary neutron star mergers. The measurement of spin can provide important information about binary formation channels. In the absence of a strong neutron star spin prior, ... More
A novel analytical model of the magnetic field configuration in the Galactic CenterJun 12 2019The magnetic field in the Galactic Center (GC) is challenging to measure in detail due to its large distance in combination with a difficult foreground estimate. More precise knowledge is, however, required in particular in the context of proper modeling ... More
Atmospheric neutrinos and the knee of the Cosmic Ray spectrumJun 12 2019The nature of the knee in the all-particle spectrum of cosmic rays remains subject of much investigation, especially in the aftermath of recent measurements claiming the detection of a knee-like feature in the spectrum of the light component of cosmic ... More
A model for microquasars of Population IIIJun 12 2019Current simulations indicate that the first stars were formed predominantly in binary systems. The study of the contribution of the first accreting binary systems to the reionization and heating of the intergalactic medium requires the formulation of ... More
Hydrodynamical instabilities in superfluid neutron stars with background flows between the componentsJun 12 2019The interiors of mature neutron stars are expected to be superfluid. Superfluidity of matter on the microscopic scale can have a number of large scale, potentially observable consequences, as the superfluid component of the star can now flow relative ... More
Parametrized black hole quasinormal ringdown. II. Coupled equations and quadratic corrections for nonrotating black holesJun 12 2019Linear perturbations of spherically symmetric spacetimes in general relativity are described by radial wave equations, with potentials that depend on the spin of the perturbing field. In previous work we studied the quasinormal mode spectrum of spacetimes ... More
Dynamics of magnetic flux tubes in accretion discs of T Tauri starsJun 12 2019Dynamics of slender magnetic flux tubes (MFT) in the accretion discs of T Tauri stars is investigated. We perform simulations taking into account buoyant, aerodynamic and turbulent drag forces, radiative heat exchange between MFT and ambient gas, magnetic ... More
Impact of electron capture rates on nuclei far from stability on core-collapse supernovaeJun 12 2019The impact of electron-capture (EC) cross sections on neutron-rich nuclei on the dynamics of core-collapse during infall and early post-bounce is studied performing spherically symmetric simulations in general relativity using a multigroup scheme for ... More
The Discovery of Six Recycled Pulsars from the Arecibo 327-MHz Drift-Scan Pulsar SurveyJun 12 2019Recycled pulsars are old ($\gtrsim10^{8}$ yr) neutron stars that are descendants from close, interacting stellar systems. In order to understand their evolution and population, we must find and study the largest number possible of recycled pulsars in ... More
Current Status of r-Process NucleosynthesisJun 12 2019The rapid neutron capture process (r process) is believed to be responsible for about half of the production of the elements heavier than iron and contributes to abundances of some lighter nuclides as well. A universal pattern of r-process element abundances ... More
Constraints on the emission region of 3C 279 during strong flares in 2014 and 2015 through VHE gamma-ray observations with H.E.S.SJun 12 2019The flat spectrum radio quasar 3C 279 is known to exhibit pronounced variability in the high-energy ($100\,$MeV$<E<100\,$GeV) $\gamma$-ray band, which is continuously monitored with Fermi-LAT. During two periods of high activity in April 2014 and June ... More
Relativistic wind accretion on to a Schwarzschild black holeJun 12 2019We present a novel analytic model of relativistic wind accretion on to a Schwarzschild black hole. This model constitutes a general relativistic extension of the classical model of wind accretion by Bondi, Hoyle, and Lyttleton (BHL). As in BHL, this model ... More
Primordial Extremal Black Holes as Dark MatterJun 11 2019We show that primordial (nearly) extremal black holes with a wide range of masses from the Planck scale to around $10^9$ g could be cosmologically stable and explain dark matter, given a dark electromagnetism and a heavy dark electron. For individual ... More
Hard state accretion disk winds from black holes: the revealing case of MAXI J1820+070Jun 11 2019We report on a detailed optical spectroscopic follow-up of the black hole transient MAXI J1820+070 (ASASSN-18ey). The observations cover the main part of the X-ray binary outburst, when the source alternated between hard and soft states following the ... More
Discovery of a 2.8 s pulsar in a 2 d orbit High-Mass X-ray Binary powering the Ultraluminous X-ray source ULX-7 in M51Jun 11 2019Jun 13 2019We discovered 2.8 s pulsations in the X-ray emission of the ultraluminous X-ray source (ULX) M51 ULX-7 within the UNSEeN project, which was designed to hunt for new pulsating ULXs (PULXs) with XMM-Newton. The pulse shape is sinusoidal and large variations ... More
Discovery of a 2.8 s pulsar in a 2 d orbit High-Mass X-ray Binary powering the Ultraluminous X-ray source ULX-7 in M51Jun 11 2019We discovered 2.8 s pulsations in the X-ray emission of the ultraluminous X-ray source (ULX) M51 ULX-7 within the UNSEeN project, which was designed to hunt for new pulsating ULXs (PULXs) with XMM-Newton. The pulse shape is sinusoidal and large variations ... More
Dissecting a disk-instability outburst in a symbiotic star: $NuSTAR$, and $Swift$ observations of T Coronae Borealis during the rise to the "super-active" stateJun 11 2019The current $super-active$ state of the recurrent nova T CrB has been observed with unprecedented detail. Previously published observations provide strong evidence that this state is due to an enhancement of the flow of material through the accretion ... More
Constraining primordial black hole masses with the isotropic gamma ray backgroundJun 11 2019Primordial black holes can represent all or most of the dark matter in the window $10^{17}-10^{22}\,$g. Here we present an extension of the constraints on PBHs of masses $10^{13}-10^{18}\,$g arising from the isotropic diffuse gamma ray background. Primordial ... More
Measuring clock jumps using pulsar timingJun 11 2019In this paper, we investigate the statistical signal-processing algorithm to measure the instant local clock jump from the timing data of multiple pulsars. Our algorithm is based on the framework of Bayesian statistics. In order to make the Bayesian algorithm ... More
Multiwavelength Study of the X-Ray Bright Supernova Remnant N300-S26 in NGC 300Jun 11 2019We present a multiwavelength examination of the supernova remnant (SNR) S26 in the nearby galaxy NGC 300 using data from Chandra X-ray Observatory, XMM-Newton X-ray Observatory, Hubble Space Telescope (HST), the Very Large Array, and the Australia Telescope ... More
The binary millisecond pulsar PSR J1023+0038 -- II. Optical spectroscopyJun 11 2019We present time-resolved optical spectroscopy of the `redback' binary millisecond pulsar system PSR J1023+0038 during both its radio pulsar (2009) and accretion disc states (2014 and 2016). We provide observational evidence for the companion star being ... More
Extremely High energy peaked BL Lac nature of the TeV blazar Mrk 501Jun 11 2019Extremely High energy peaked BL Lac (EHBL) objects are a special class of blazars with peculiar observational properties at X-ray and $\gamma$--ray energies. The observations of these sources indicate hard X-ray and $\gamma$--ray spectra and absence of ... More
The effective magnetic field decay of radio pulsars: insights from the statistical properties of their spin frequency's second derivativesJun 11 2019We present a new method to investigate the effective magnetic field decay of isolated neutron stars, from the analysis of the long-term timing data of a large sample of radio pulsars \citep{2010MNRAS.402.1027H}. There are some differences between the ... More
A Search for a Contribution from Axion-Like Particles to the X-Ray Diffuse Background Utilizing the Earth's Magnetic FieldJun 11 2019Axion Like Particle (ALP) is a hypothetical particle of quantum field which works to conserve CP symmetry in the strong interaction, and also one of candidates of the Cold Dark Matter (CDM) in the Universe. ALP can be converted into photons via its interaction ... More
Temporal and spectral X-ray properties of magnetar SGR 1900+14 derived from observations with NuSTAR and XMM-NewtonJun 11 2019X-ray observations play a crucial role in understanding the emission mechanism and relevant physical phenomena of magnetars. We report X-ray observations of a young magnetar SGR 1900+14 made in 2016, which is famous for a giant flare in 1998 August. Simultaneous ... More
Dependence of outer boundary condition on protoneutron star asteroseismology with gravitational-wave signaturesJun 11 2019To obtain the eigenfrequencies of a protoneutron star (PNS) in the postbounce phase of core-collapse supernovae (CCSNe), we perform a linear perturbation analysis of the angle-averaged PNS profiles using results from a general relativistic CCSN simulation ... More
Cosmic Ray Spectrum and Composition from PeV to EeV Using 3 Years of Data From IceTop and IceCubeJun 10 2019We report on measurements of the all-particle cosmic ray energy spectrum and composition in the PeV to EeV energy range using three years of data from the IceCube Neutrino Observatory. The IceTop detector measures cosmic ray induced air showers on the ... More
ALMA observations of A0620-00: fresh clues on the nature of quiescent black hole X-ray binary jetsJun 10 2019We report on ALMA continuum observations of the black hole X-ray binary A0620-00, at an X-ray luminosity nine orders of magnitude sub-Eddington. The system was significantly detected at 98 GHz (at $44 \pm 7~\mu{\rm Jy}$) and only marginally at 233 GHz ... More
POSSIS: predicting spectra, light curves and polarization for multi-dimensional models of supernovae and kilonovaeJun 10 2019We present POSSIS, a time-dependent three-dimensional Monte Carlo code for modelling radiation transport in supernovae and kilonovae. The code incorporates wavelength- and time-dependent opacities and predicts viewing-angle dependent spectra, light curves ... More
Gravitational-wave detection rates for compact binaries formed in isolation: LIGO/Virgo O3 and beyondJun 10 2019Using simulations performed with the population synthesis code MOBSE, we compute the merger rate densities and detection rates of compact binary mergers formed in isolation for second- and third-generation gravitational-wave detectors. We estimate how ... More
Maximally Rotating Supermassive Stars at the Onset of Collapse: Effects of Gas PressureJun 10 2019Jun 12 2019The "direct collapse" scenario has emerged as a promising evolutionary track for the formation of supermassive black holes early in the Universe. In an idealized version of such a scenario, a uniformly rotating supermassive star spinning at the mass-shedding ... More
Maximally Rotating Supermassive Stars at the Onset of Collapse: Effects of Gas PressureJun 10 2019The "direct collapse" scenario has emerged as a promising evolutionary track for the formation of supermassive black holes early in the Universe. In an idealized version of such a scenario, a uniformly rotating supermassive star spinning at the mass-shedding ... More
Explosions Driven by the Coalescence of a Compact Object with the Core of a Massive-Star Companion Inside a Common Envelope: Circumstellar Properties, Light Curves, and Population StatisticsJun 10 2019We model explosions driven by the coalescence of a black hole or neutron star with the core of its massive-star companion. Upon entering a common envelope phase, a compact object may spiral all the way to the core. The concurrent release of energy is ... More
X-Ray and Gamma-Ray Emission From Core-collapse Supernovae: Comparison of Three-dimensional Neutrino-driven Explosions With SN 1987AJun 10 2019During the first few hundred days after the explosion, core-collapse supernovae (SNe) emit down-scattered X-rays and gamma-rays originating from radioactive line emissions, primarily from the $^{56}$Ni $\rightarrow$ $^{56}$Co $\rightarrow$ $^{56}$Fe chain. ... More
Treating quarks within neutron starsJun 10 2019Neutron star interiors provide the opportunity to probe properties of cold dense matter in the QCD phase diagram. Utilizing models of dense matter in accord with nuclear systematics at nuclear densities, we investigate the compatibility of deconfined ... More
Astrophysical Black Holes: A ReviewJun 10 2019In this review, I have tried to focus on the development of the field, from the first speculations to the current lines of research. According to Einstein's theory of general relativity, black holes are relatively simple objects and completely characterized ... More
Targeted search for young radio pulsars in the SMC: Discovery of two new pulsarsJun 10 2019We report the first rotation powered pulsars discovered in the Small Magellanic Cloud (SMC) in more than a decade. PSR J0043-73 and PSR J0052-72 were discovered during a Parkes Multi-Beam (PMB) survey of MCSNR J0127-7332, and five new, optically selected, ... More
The environment of supernova remnant VRO 42.05.01 as probed with IRAM 30m molecular line observationsJun 10 2019The environment of supernova remnants (SNRs) is a key factor in their evolution, particularly at later stages of their existence. It is often assumed that mixed-morphology (MM) SNRs evolve in very dense environments, and that their centre-filled X-ray ... More
An introduction to astrophysical observables in gravitational wave detectionsJun 09 2019Our knowledge and understanding of the Universe is mainly based on observations of the electromagnetic radiation in a wide range of wavelengths. Only during the past two decades, new kinds of detectors have been developed, exploiting other forms of cosmic ... More
Insight-HXMT observations of the Crab pulsarJun 09 2019We report on X-ray emission properties of the Crab pulsar(PSR B0531+21) using observations by Insight-HXMT during its first year after launch. We obtained high signal-to-noise profiles in the X-ray energy band 11-250 keV. We have confirmed an increase ... More
The late-time afterglow evolution of long gamma-ray bursts GRB 160625B and GRB 160509AJun 08 2019We present post-jet-break \textit{HST}, VLA and \textit{Chandra} observations of the afterglow of the long $\gamma$-ray bursts GRB 160625B (between 69 and 209 days) and GRB 160509A (between 35 and 80 days). We calculate the post-jet-break decline rates ... More
Learning Transient Universe in Near-Ultraviolet By Wide-angle CamerasJun 08 2019We perform a detailed analysis and simulations on the transient detection capability in the near-ultraviolet (NUV) band by focusing on some major local transient events. These events include the tidal disruption event due to a supermassive blackhole, ... More
Searching for Dark Matter in the Galactic Halo with a Wide Field-of-View TeV Gamma-ray Observatory in the Southern HemisphereJun 07 2019Despite mounting evidence that astrophysical dark matter exists in the Universe, its fundamental nature remains unknown. In this paper, we present the prospects to detect and identify dark matter particles through the observation of very-high-energy ($\gtrsim$ ... More
Relativistic Magnetic Reconnection in Electron-Positron-Proton Plasmas: Implications for Jets of Active Galactic NucleiJun 07 2019Magnetic reconnection is often invoked to explain the non-thermal radiation of relativistic outflows, including jets of active galactic nuclei (AGN). Motivated by the largely unknown plasma composition of AGN jets, we study reconnection in the unexplored ... More
The First Candidate Colliding-Wind Binary in M33Jun 07 2019We present the detection of the first candidate colliding-wind binary (CWB) in M33, located in the giant H II region NGC 604. The source was first identified in archival {\it Chandra} imaging as a relatively soft X-ray point source, with the likely primary ... More
Efficient Production of Sound Waves by AGN Jets in the Intracluster MediumJun 07 2019We investigate the interaction between active galactic nuclei (AGN) jets and the intracluster medium (ICM) of galaxy clusters. Specifically, we study the efficiency with which jets can drive sound waves into the ICM. Previous works focused on this issue ... More
Evolution of black hole shadow in the presence of ultralight bosonsJun 07 2019The possible occurence of ultralight boson clouds around Kerr black holes has attracted a lot of interest. In this work, we determine the signatures of boson cloud evolution in the shadow of a black hole. We assess the detectability of such variations ... More
A NuSTAR view of powerful gamma-ray loud blazarsJun 07 2019We observed with the NuSTAR satellite 3 blazars at z>2, detected in gamma-rays by Fermi/LAT and in the soft X-rays, but not yet observed above 10 keV. The flux and slope of their X-ray continuum, together with Fermi/LAT data allows us to estimate their ... More
SDSS J094635.06+101706.1: a redshift one, very radio-loud, γ-ray emitting narrow-line Seyfert 1 galaxyJun 07 2019As hybrids of narrow-line Seyfert 1 (NLS1) galaxies and blazars, {\gamma}-ray emitting NLS1s are important probes of jet physics in the high Eddington-ratio regime. Only very few of them are known to date; the majority of them below redshift z = 0.5. ... More
Pulse Phase Variation of Cyclotron Line in HMXB 4U 1907+09 with ASTROSAT LAXPCJun 07 2019We present timing and spectral analysis of data from an observation of the High Mass X-ray Binary pulsar 4U 1907+09 with the LAXPC instrument onboard AstroSat. The light curve consisted of a flare at the beginning of the observation, followed by persistent ... More
Plerion model of the X-ray plateau in short gamma-ray burstsJun 07 2019Many short gamma-ray bursts (sGRBs) exhibit a prolonged plateau in the X-ray light curve following the main burst. It is shown that an X-ray plateau at the observed luminosity emerges naturally from a plerion-like model of the sGRB remnant, in which the ... More
Multi-waveform cross-correlation search method for intermediate-duration gravitational waves from gamma-ray burstsJun 06 2019Gamma-ray Bursts (GRBs) are flashes of gamma-rays thought to originate from rare forms of massive star collapse (long GRBs), or from mergers of compact binaries (short GRBs) containing at least one neutron star (NS). The nature of the post-explosion / ... More
A joint NICER and XMM-Newton view of the "Magnificent" thermally emitting X-ray Isolated Neutron Star RX J1605.3+3249Jun 06 2019Thermally emitting X-ray isolated neutron stars represent excellent targets for testing cooling surface emission and atmosphere models, which are used to infer physical parameters of the neutron star. Among the seven known members of this class, RX J1605.3+3249 ... More
Searching for fast extragalactic X-ray transients in Chandra surveysJun 06 2019Recent works have discovered two fast ($\approx 10$ ks) extragalactic X-ray transients in the Chandra Deep Field-South (CDF-S XT1 and XT2). These findings suggest that a large population of similar extragalactic transients might exist in archival X-ray ... More
Multiphase quasar-driven outflows in PG 1114+445. I. Entrained ultra-fast outflowsJun 06 2019Substantial evidence in the last few decades suggests that outflows from supermassive black holes (SMBH) may play a significant role in the evolution of galaxies. Large-scale outflows known as warm absorbers (WA) and fast disk winds known as ultra-fast ... More
Inferring black hole spins and probing accretion/ejection flows in AGNs with the Athena X-ray Integral Field UnitJun 06 2019Active Galactic Nuclei (AGN) display complex X-ray spectra which exhibit a variety of emission and absorption features, that are commonly interpreted as a combination of i) a relativistically smeared reflection component, resulting from the irradiation ... More
Non-thermal emission from the reverse shock of the youngest galactic Supernova remnant G1.9+0.3Jun 06 2019Context. The youngest Galactic supernova remnant G1.9+0.3 is an interesting target for next generation gamma-ray observatories. So far, the remnant is only detected in the radio and the X-ray bands, but its young age of ~100 yrs and inferred shock speed ... More
The long-term temperature evolution of neutron stars undergoing episodic accretion outburstsJun 06 2019Transiently accreting neutron stars (NSs) in LMXBs undergo episodes of accretion, alternated with periods of quiescence. During an accretion outburst, the NS heats up due to exothermic accretion-induced processes taking place in the crust. Most of this ... More
Astrophysical aspects of general relativistic mass twin starsJun 06 2019In this chapter we will introduce an effective equation of state (EoS) model based on polytropes that serves to study the so called "mass twins" scenario, where two compact stars have approximately the same mass but (significant for observation) quite ... More
On the radiation energy density in the jet of high-energy emitting BL Lac objects and its impact on their multi-messenger roleJun 06 2019We examine the potential multi-messenger role of BL Lac objects emitting at high energy (so-called HBL) focusing on the limits on the energy density of soft radiation in the jet frame, a critical parameter which regulates the proton cooling and the fragmentation ... More
Pulsar wind-heated accretion disk and the origin of modes in transitional millisecond pulsar PSR J1023+0038Jun 06 2019Transitional millisecond pulsars provide a unique set of observational data for understanding accretion at low rates onto magnetized neutron stars. In particular, PSR~J1023+0038 exhibits a remarkable bimodality of the X-ray luminosity (low and high modes), ... More
Cosmic Ray Acceleration in Hydromagnetic Flux TubesJun 06 2019We find that hydromagnetic flux tubes in back-flows in the lobes of radio galaxies offer a suitable environment for the acceleration of cosmic rays (CR) to ultra-high energies. We show that CR can reach the Hillas (1984) energy even if the magnetised ... More
Application of the Thermal Wind Model to Absorption Features in the Black Hole X-ray Binary H 1743-322Jun 06 2019High inclination black hole X-ray binaries exhibit blueshifted ionized absorption lines from disk winds, whose launching mechanism is still in debate. The lines are predominantly observed in the high/soft state and disappear in the low/hard state. We ... More
On the Cosmological Evolution of Long Gamma-ray Burst PropertiesJun 05 2019We examine the relationship between a number of long gamma-ray burst (lGRB) properties (isotropic emitted energy, luminosity, intrinsic duration, jet opening angle) and redshift. We find that even when accounting for conservative detector flux limits, ... More
Radio emission features in different modes of PSR J0826+2637 (B0823+26)Jun 05 2019We report on a detailed analysis of the radio emission during the different modes of the pulsar J0826+2637 (B0823+26), observed using the Giant Meterwave Radio Telescope at 306-339 MHz observing frequencies. The pulsar profile has a postcursor and interpulse ... More
Probing high-energy interactions of atmospheric and astrophysical neutrinosJun 05 2019Astrophysical and atmospheric neutrinos are important probes of the powerful accelerators that produce cosmic-rays with EeV energies. Understanding these accelerators is a key goal of neutrino observatories, along with searches for neutrinos from supernovae, ... More
The dust content of the Crab NebulaJun 05 2019We have modelled the near-infrared to radio images of the Crab Nebula with a Bayesian SED model to simultaneously fit its synchrotron, interstellar and supernova dust emission. We infer an interstellar dust extinction map with an average $A_{\text{V}}$=1.08$\pm$0.38 ... More
Pseudo-Goldstone dark matter confronts cosmic ray and collider anomaliesJun 05 2019Persistent excesses in the spectra of gamma rays from the galactic center and cosmic ray antiprotons can be explained by dark matter of mass 50-65 GeV annihilating into $b$ quarks, but this is typically hard to reconcile with direct detection constraints. ... More
Angular momentum in bipolar outflows: dynamical evolutionary modelJun 05 2019We model molecular outflows produced by the time dependent interaction between a stellar wind and a rotating cloud envelope in gravitational collapse, studied by Ulrich. We consider spherical and anisotropic stellar winds. We assume that the bipolar outflow ... More
Superfluid Phase Transitions and Effects of Thermal Pairing Fluctuations in Asymmetric Nuclear MatterJun 05 2019We investigate superfluid phase transitions of asymmetric nuclear matter at finite temperature ($T$) and density ($\rho$) with a low proton fraction ($Y_{\rm p} \le 0.2$) which is relevant to the inner crust and outer core of neutron stars. A strong-coupling ... More
Equation of state effects in the core collapse of a $20$-$M_\odot$ starJun 05 2019Uncertainties in our knowledge of the properties of dense matter near and above nuclear saturation density are among the main sources of variations in multi-messenger signatures predicted for core-collapse supernovae (CCSNe) and the properties of neutron ... More
Investigating subphotospheric dissipation in gamma-ray bursts using joint Fermi-Swift observationsJun 05 2019The jet photosphere has been proposed as the origin for the gamma-ray burst (GRB) prompt emission. In many such models, characteristic features in the spectra appear below the energy range of the $\textit{Fermi}$ GBM detectors, so joint fits with X-ray ... More
Indications of non-conservative mass-transfer in AMXPsJun 05 2019Context. Since the discovery of the first Accreting Millisecond X-ray Pulsar SAX J1808.4-3658 in 1998, the family of these sources kept growing on. Currently, it counts 22 members. All AMXPs are transients with usually very long quiescence periods, implying ... More
Insight-HXMT observations of Swift J0243.6+6124 during its 2017-2018 outburstJun 05 2019The recently discovered neutron star transient Swift J0243.6+6124 has been monitored by {\it the Hard X-ray Modulation Telescope} ({\it Insight-\rm HXMT). Based on the obtained data, we investigate the broadband spectrum of the source throughout the outburst. ... More
The early life of millisecond magnetarsJun 05 2019Some neutron stars may be born spinning fast and with strong magnetic fields---the so-called \emph{millisecond magnetars}. It is important to understand how a star's magnetic axis moves with respect to the spin axis in the star's early life, as this effects ... More
The Role of Energy Diffusion in the Deposition of Energetic Electron Energy in Solar and Stellar FlaresJun 05 2019During solar flares, a large fraction of the released magnetic energy is carried by energetic electrons that transfer and deposit energy in the Sun's atmosphere. Electron transport is often approximated by a cold thick-target model (CTTM), assuming that ... More
Wave dispersion in pulsar plasma: 3. Beam-driven instabilitiesJun 05 2019Beam-driven instabilities are considered in a pulsar plasma assuming that both the background plasma and the beam are relativistic J\"uttner distributions. In the rest frame of the background, the only waves that can satisfy the resonance condition are ... More
An optical and X-ray study of the contact binary, BH CassiopeiaJun 05 2019We present the revised and high quality CCD time series observations in 2017 and 2018 of the W UMa-type contact binary BH~Cas. The combination of our new determinations of minimum times and those collected from the literatures reveal a long-term period ... More
The Duration of Star Formation in Galactic Giant Molecular Clouds. I. The Great Nebula in CarinaJun 04 2019We present a novel infrared spectral energy distribution (SED) modeling methodology that uses likelihood-based weighting of the model fitting results to construct probabilistic H-R diagrams (pHRD) for X-ray identified, intermediate-mass (2-8 $M_{\odot}$), ... More
Neutron matter at the interface(s): from interactions to ab initio and from there to phenomenologyJun 04 2019Neutron matter is interesting both as an extension of terrestrial nuclear physics and due to its significance for the study of neutron stars. In this work, after some introductory comments on nuclear forces, nuclear ab initio theory, and nuclear phenomenology, ... More
NuRadioMC: Simulating the radio emission of neutrinos from interaction to detectorJun 04 2019NuRadioMC is a Monte Carlo framework designed to simulate ultra-high energy neutrino detectors that rely on the radio detection method. This method exploits the radio emission generated in the electromagnetic component of a particle shower following a ... More
How to produce antihelium from dark matterJun 04 2019We show how to produce antihelium and other antinuclei in large fractions from the decays of a new particle $\phi$ that carries baryon number. Close to threshold, the production of nuclear bound states is preferred over the decay into individual nucleons, ... More
Search for gamma-ray counterparts of newly discovered radio astrophysical sourcesJun 04 2019In this paper we study two newly discovered classes of radio sources: the highly energetic, short-lived events, known as Fast Radio Bursts (FRBs), and a new category of compact sources known as Fanaroff-Riley type 0 radio galaxies (FR0s). Due to a possible ... More
Prospects for Detecting X-ray Polarization in Blazar JetsJun 04 2019X-ray polarization should provide new probes of magnetic field geometry and acceleration physics near the base of blazar jets, but near-future missions will have limited sensitivity. We thus use existing lower energy data and X-ray variability measurements ... More
Chandra reveals a possible ultra-fast outflow in the super-Eddington Be/X-ray binary Swift J0243.6+6124Jun 04 2019Accretion at super-Eddington rates is expected to be accompanied by strong outflows. Such outflows are observed in Galactic X-ray binaries and extragalactic Ultra-luminous X-ray sources (ULXs). However, due to their large source distances, ULX outflows ... More
Crust Cooling Models are Insensitive to the Crust-Core Transition Pressure for Realistic Equations of StateJun 04 2019Neutron stars cooling after sustained accretion outbursts provide unique information about the neutron star crust and underlying dense matter. Comparisons between astronomical observations of these cooling transients and model calculations of neutron ... More
Multimessenger Probes of High-energy SourcesJun 04 2019Multimessenger observations may hold the key to learn about the most energetic sources in the universe. The recent construction of large scale observatories opened new possibilities in testing non thermal cosmic processes with alternative probes, such ... More
XMM-Newton observations of PSR J0726-2612, a radio-loud XDINSJun 04 2019We present the results of an XMM-Newton observation of the slowly rotating ($P = 3.4$ s), highly magnetized ($B \approx 3 \times 10^{13}$ G) radio pulsar PSR J0726-2612. A previous X-ray observation with the Chandra satellite showed that some of the properties ... More
Gaussian-mixture-model-based cluster analysis of gamma-ray bursts in the BATSE catalogJun 04 2019Clustering is an important tool to describe gamma-ray bursts (GRBs). We analyzed the Final BATSE Catalog using Gaussian-mixture-models-based clustering methods for six variables (durations, peak flux, total fluence and spectral hardness ratios) that contain ... More
Non-dissipative photospheres in GRBs: Spectral appearance in the Fermi/GBM catalogueJun 04 2019A large fraction of gamma-ray burst (GRB) spectra are very hard below the peak. Indeed, the observed distribution of sub-peak power-law indices, $\alpha$, has been used as an argument for a photospheric origin of GRB spectra. Here, we investigate what ... More
Negative Dynamical Friction on compact objects moving through dense gasJun 04 2019An over-dense wake is created by a gravitating object moving through a gaseous medium, and this wake pulls back on the object and slows it down. This is conventional dynamical friction in a gaseous medium. We argue that if the object drives a sufficiently ... More
Energy function, formation rate and low-metallicity environment of fast radio burstsJun 04 2019In this paper, we investigate the energy function, formation rate and environment of fast radio bursts (FRBs) using Parkes sample and Australian Square Kilometer Array Pathfinder (ASKAP) sample. For the first time, the metallicity effect on the formation ... More
Spica and the annual cycle of PKS B1322-110 scintillationsJun 04 2019PKS B1322-110 is a radio quasar that is located only 8.5' in angular separation from the bright B star Spica. It exhibits intra-day variability in its flux density at GHz frequencies attributed to scintillations from plasma inhomogeneities. We have tracked ... More