text
stringlengths
89
2.49k
category
stringclasses
19 values
Hydrodynamics of Core-Collapse Supernovae at the Transition to Explosion. I. Spherical Symmetry: We study the transition to runaway expansion of an initially stalled core-collapse supernova shock. The neutrino luminosity, mass accretion rate, and neutrinospheric radius are all treated as free parameters. In spherical...
astro-ph_HE
Constraining the lensing of binary neutron stars from their stochastic background: Gravitational wave (GW) transients from binary neutron star (BNS) coalescences can, in principle, be subject to gravitational lensing thereby increasing the amplitude and signal-to-noise ratio. We estimate the rate of lensed BNS events...
astro-ph_HE
Inferences from the Distributions of Fast Radio Burst Pulse Widths, Dispersion Measures and Fluences: The widths, dispersion measures, dispersion indices and fluences of Fast Radio Bursts (FRB) impose coupled constraints that all models must satisfy. Observation of dispersion indices close to their low density limit ...
astro-ph_HE
Electromagnetic Window into the Dawn of Black Holes: Massive 10^6-10^10 Msun black holes (BHs) are ubiquitous in local galactic nuclei. They were common by the time the Universe is several Gyr old, and many of them were in place within the first 1~Gyr after the Big Bang. Their quick assembly has been attributed to mech...
astro-ph_HE
Dynamical Formation Scenarios for GW190521 and Prospects for Decihertz Gravitational-Wave Astronomy with GW190521-Like Binaries: The gravitational-wave (GW) detection of GW190521 has provided new insights on the mass distribution of black holes and new constraints for astrophysical formation channels. With independen...
astro-ph_HE
Evidence for GeV Pair Halos around Low Redshift Blazars: We report on the results of a search for $\gamma$-ray pair halos with a stacking analysis of low-redshift blazars using data from the Fermi Large Area Telescope. For this analysis we used a number of a-priori selection criteria, including the spatial and spectral...
astro-ph_HE
The XMM-Newton survey of the Small Magellanic Cloud: XMMUJ010633.1-731543 and XMMUJ010743.1-715953, two new Be/X-ray binary systems: In the course of the XMM-Newton survey of the Small Magellanic Cloud (SMC), two new bright X-ray sources were discovered exhibiting the spectral characteris- tics of High Mass X-ray B...
astro-ph_HE
Lorentz Violation: Motivation and new constraints: We review the main theoretical motivations and observational constraints on Planck scale suppressed violations of Lorentz invariance. After introducing the problems related to the phenomenological study of quantum gravitational effects, we discuss the main theoretical ...
astro-ph_HE
Investigating evidence for different black hole accretion modes since redshift z~1: Chandra data in the COSMOS, AEGIS-XD and 4Ms CDFS are combined with optical/near-IR photometry to determine the rest-frame U-V vs V-J colours of X-ray AGN hosts at mean redshifts 0.40 and 0.85. This combination of colours (UVJ) provid...
astro-ph_HE
Can very massive Population III stars produce a super-collapsar?: A fraction of the first generation of stars in the early Universe may be very massive ($\gtrsim 300~\mathrm{M_\odot}$) as they form in metal-free environments. Formation of black holes from these stars can be accompanied by supermassive collapsars to pro...
astro-ph_HE
Observation of Anisotropy in the Arrival Direction Distribution of TeV Cosmic Rays with HAWC: The High-Altitude Water Cherenkov (HAWC) Observatory, located 4100 m above sea level near Sierra Negra (19$^\circ$ N) in Mexico, is sensitive to gamma rays and cosmic rays at TeV energies. The arrival direction distribution ...
astro-ph_HE
A systematic study of photoionized emission and warm absorption signatures of the NLS1 Mrk 335: We present an analysis of all the archival high resolution spectra of the Narrow-line Seyfert 1 galaxy Mrk~335 obtained with Reflection Grating Spectrometer (RGS) on board \textit{XMM-Newton}. The spectra show rich emissio...
astro-ph_HE
Growing evidence that SNe Iax are not a one-parameter family: the case of PS1-12bwh: In this study, we present observations of a type Iax supernova, PS1-12bwh, discovered during the Pan-STARRS1 3$\pi$-survey. Our analysis was driven by previously unseen pre-maximum, spectroscopic heterogeneity. While the light curve ...
astro-ph_HE
Superorbital modulation at GeV energies in the gamma-ray binary LS I +61 303: We report the results from our analysis of 8 years of the data for the gamma-ray binary LS I +61 303, obtained with the Large Area Telescope onboard the Fermi Gamma-Ray Space Telescope. We find a significant dip around the binary's periastr...
astro-ph_HE
The Einstein@Home Gamma-ray Pulsar Survey. I. Search Methods, Sensitivity and Discovery of New Young Gamma-ray Pulsars: We report on the results of a recent blind search survey for gamma-ray pulsars in Fermi Large Area Telescope (LAT) data being carried out on the distributed volunteer computing system, Einstein@Home...
astro-ph_HE
A tale of two mergers: constraints on kilonova detection in two short GRBs at z$\sim$0.5: We present a detailed multi-wavelength analysis of two short Gamma-Ray Bursts (sGRBs) detected by the Neil Gehrels Swift Observatory: GRB 160624A at $z=0.483$ and GRB 200522A at $z=0.554$. These sGRBs demonstrate very different ...
astro-ph_HE
Variety of disk wind-driven explosions in massive rotating stars: We perform a set of two-dimensional, non-relativistic, hydrodynamics simulations for supernova-like explosion associated with stellar core collapse of rotating massive stars to a system of a black hole and a disk connected by the transfer of matter and a...
astro-ph_HE
The Spectral Sharpness Angle of Gamma-ray Bursts: We explain the results of Yu et al. (2015b) of the novel sharpness angle measurement to a large number of spectra obtained from the Fermi gamma-ray burst monitor. The sharpness angle is compared to the values obtained from various representative emission models: blackbo...
astro-ph_HE
r-Process Lanthanide Production and Heating Rates in Kilonovae: r-Process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the loc...
astro-ph_HE
Sub-arcsecond radio and optical observations of the likely counterpart to the gamma-ray source 2FGL J2056.7+4939: We have searched and reviewed all multi- wavelength data available for the region towards the gamma-ray source 2FGL J2056.7+4939 in order to con- strain its possible counterpart at lower energies. As a re...
astro-ph_HE
Investigating the true nature of three hard X-ray sources: Many of the new high energy sources discovered both by INTEGRAL/IBIS and Swift/BAT have been characterised thanks to extensive, multi-band follow-up campaigns, but there are still objects whose nature remains to be asserted. In this paper we investigate the tru...
astro-ph_HE
Exploring properties of high-density matter through remnants of neutron-star mergers: Remnants of neutron-star mergers are essentially massive, hot, differentially rotating neutron stars, which are initially strongly oscillating. They represent a unique probe for high-density matter because the oscillations are detec...
astro-ph_HE
Intrinsic disc emission and the Soft X-ray Excess in AGN: (Abridged) Narrow Line Seyfert 1 (NLS1) galaxies have low mass black holes and mass accretion rates close to (or exceeding) Eddington, so a standard blackbody accretion disc should peak in the EUV. However, the lack of true absorption opacity in the disc means t...
astro-ph_HE
Magnetic-distortion-induced ellipticity and gravitational wave radiation of neutron stars: millisecond magnetars in short GRBs, Galactic pulsars, and magnetars: Neutron stars may sustain a non-axisymmetric deformation due to magnetic distortion and are potential sources of continuous gravitational waves (GWs) for g...
astro-ph_HE
Implications on the origin of cosmic rays in light of 10 TV spectral softenings: Precise measurements of the energy spectra of cosmic rays (CRs) show various kinds of features deviating from single power-laws, which give very interesting and important implications on their origin and propagation. Previous measurement...
astro-ph_HE
Maximum mass of a hybrid star having a mixed phase region in the light of pulsar PSR J1614-2230: Recent observation of pulsar PSR J1614-2230 with mass about 2 solar masses poses a severe constraint on the equations of state (EOS) of matter describing stars under extreme conditions. Neutron stars (NS) can reach the ma...
astro-ph_HE
Mass and radius relations of quarkyonic stars using an excluded volume model: Inspired by the excluded volume model for isospin symmetric quarkyonic matter, we construct an `excluded volume' model for a charge neutral quarkyonic phase whose hadronic sector contains only neutrons. We refer to this model as quarkyonic ...
astro-ph_HE
Stellar and AGN feedback in isolated early-type galaxies: the role in regulating star formation and ISM properties: Understanding how galaxies maintain the inefficiency of star formation with physically self-consistent models is a central problem for galaxy evolution. Although numerous theoretical models have been pr...
astro-ph_HE
The polarized Gamma-Ray Burst GRB 061122: We report on the polarization measure, obtained with IBIS on board INTEGRAL, of the prompt emission of GRB 061122. Over an 8 s interval containing the brightest part of the Gamma-Ray Burst we put a lower limit on its polarization fraction of 60% at 68% c.l. and of 33% at 90% c....
astro-ph_HE
Assessing the Observability of Hypernovae and Pair-Instability Supernovae in the Early Universe: The era of the universe's first (Population III) stars is essentially unconstrained by observation. Ultra-luminous and massive stars from this time altered the chemistry of the cosmos, provided the radiative scaffolding t...
astro-ph_HE
Binary Black Hole Accretion From a Circumbinary Disk: Gas Dynamics Inside the Central Cavity: We present the results of 2D hydrodynamical simulations of circumbinary disk accretion using the finite-volume code DISCO. This code solves the 2D viscous Navier-Stokes equations on a high-resolution moving mesh which shears...
astro-ph_HE
Nucleosynthesis in magnetorotational supernovae: impact of the magnetic field configuration: The production of heavy elements is one of the main by-products of the explosive end of massive stars. A long sought goal is finding differentiated patterns in the nucleosynthesis yields, which could permit identifying a numb...
astro-ph_HE
ThunderKAT: The MeerKAT Large Survey Project for Image-Plane Radio Transients: ThunderKAT is the image-plane transients programme for MeerKAT. The goal as outlined in 2010, and still today, is to find, identify and understand high-energy astrophysical processes via their radio emission (often in concert with observat...
astro-ph_HE
The Luminosity Distribution of Short Gamma-Ray Bursts under a Structured Jet Scenario: Luminosity of GRB 170817A is much lower than that of other sGRBs. The measurement of the superluminal movement of the radio afterglow emission confirms the presence of the relativistic jet, and the emission features can be well exp...
astro-ph_HE
Multi-waveform cross-correlation search method for intermediate-duration gravitational waves from gamma-ray bursts: Gamma-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 neut...
astro-ph_HE
Enhanced X-ray emission from Lyman Break Analogues and a Possible $L_{\rm X}$--SFR--Metallicity Plane: The source of energetic photons that heated and reionized the early Universe remains uncertain. Early galaxies had low metallicity and recent population synthesis calculations suggest that the number and luminosity ...
astro-ph_HE
Detectability of Sub-Solar Mass Neutron Stars Through a Template Bank Search: We study the detectability of gravitational-wave signals from sub-solar mass binary neutron star systems by the current generation of ground-based gravitational-wave detectors. We find that finite size effects from large tidal deformabiliti...
astro-ph_HE
The long-term optical evolution of the black hole candidate MAXI J1659-152: We present 5 years of optical and infrared data of the black hole candidate MAXI J1659-152 covering its 2010 outburst, decay and quiescence. Combining optical data taken during the outburst decay, we obtain an orbital period of 2.414 $\pm$ 0....
astro-ph_HE
Glitches: the exact quantum signatures of pulsars metamorphosis: The observed recurrence of glitches in pulsars and neutron stars carry rich information about the evolution of their internal structures. In this article I show that the glitch-events observed in pulsars are exact quantum signatures for their metamorphosi...
astro-ph_HE
Quantifying How Density Gradients and Front Curvature Affect Carbon Detonation Strength During Type Ia Supernovae: Accurately reproducing the physics behind the detonations of Type Ia supernovae and the resultant nucleosynthetic yields is important for interpreting observations of spectra and remnants. The scales of ...
astro-ph_HE
Using machine learning for transient classification in searches for gravitational-wave counterparts: The large sky localization regions offered by the gravitational-wave interferometers require efficient follow-up of the many counterpart candidates identified by the wide field-of-view telescopes. Given the restricted...
astro-ph_HE
Search for gravitational waves associated with gamma-ray bursts during LIGO science run 6 and Virgo science runs 2 and 3: We present the results of a search for gravitational waves associated with 154 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments in 2009-2010, during the sixth LI...
astro-ph_HE
A New Spin on an Old Black Hole: NuSTAR Spectroscopy of EXO 1846-031: The black hole candidate EXO 1846-031 underwent an outburst in 2019, after at least 25 years in quiescence. We observed the system using \textit{NuSTAR} on August 3rd, 2019. The 3--79 keV spectrum shows strong relativistic reflection features. Our ba...
astro-ph_HE
Jet Suppression by Accretion Disk Winds in the Microquasar GRS 1915+105: Stellar-mass black holes with relativistic jets, also known as microquasars, mimic the behavior of quasars and active galactic nuclei. Because timescales around stellar-mass black holes are orders of magnitude smaller than those around more distan...
astro-ph_HE
Supergiant Fast X-ray Transients with Swift: spectroscopic and temporal properties: Supergiant fast X-ray transients (SFXTs) are a class of high-mass X-ray binaries with possible counterparts in the high energy gamma rays. The Swift SFXT Project has conducted a systematic investigation of the properties of SFTXs on t...
astro-ph_HE
Improved early warning of compact binary mergers using higher modes of gravitational radiation: A population study: A gravitational-wave (GW) early-warning of a compact-binary coalescence event, with a sufficiently tight localisation skymap, would allow telescopes to point in the direction of the potential electromag...
astro-ph_HE
DW Cancri in x-rays: We report on the $XMM$-Newton observation of DW Cnc, a candidate intermediate polar candidate whose historical optical light curve shows the existence of periods at $\simeq 38$, $\simeq 86$ and $\simeq 69$ minutes which were interpreted as the white dwarf spin, the orbital and the spin-orbit beat p...
astro-ph_HE
Evidence for crust cooling in the transiently accreting 11-Hz X-ray pulsar in the globular cluster Terzan 5: The temporal heating and subsequent cooling of the crusts of transiently accreting neutron stars carries unique information about their structure and a variety of nuclear reaction processes. We report on a new...
astro-ph_HE
Extreme Variability in a Long Duration Gamma-ray Burst Associated with a Kilonova: The recent discovery of a kilonova from the long duration gamma-ray burst, GRB 211211A, challenges classification schemes based on temporal information alone. Gamma-ray properties of GRB 211211A reveal an extreme event, which stands ou...
astro-ph_HE
Correlations between radio and bolometric fluxes in GX 339-4 and H1743-322: Compact radio jets are ubiquitous in stellar-mass black-hole binaries in their hard spectral state. Empirical relations between the radio and narrow-band X-ray fluxes have been used to understand the connection between their accretion discs a...
astro-ph_HE
Constraints on Blazar Jet Conditions During Gamma-Ray Flaring from Radiative Transfer Modeling: As part of a program to investigate jet flow conditions during GeV gamma-ray flares detected by Fermi, we are using UMRAO multi-frequency, centimeter-band total flux density and linear polarization monitoring observations ...
astro-ph_HE
X-Ray Luminous Binaries, Metallicity, and the Early Universe: High mass X-ray binaries (HMXBs) may have had a significant impact on the heating of the intergalactic medium in the early universe. Study of HMXBs in nearby, low metallicity galaxies that are local analogues to early galaxies can help us understand early HM...
astro-ph_HE
New unidentified H.E.S.S. Galactic sources: H.E.S.S. is one of the most sensitive instruments in the very high energy (VHE; > 100 GeV) gamma-ray domain and has revealed many new sources along the Galactic Plane. After the successful first VHE Galactic Plane Survey of 2004, H.E.S.S. has continued and extended that surve...
astro-ph_HE
Modeling pulsar time noise with long term power law decay modulated by short term oscillations of the magnetic fields of neutron stars: We model the evolution of the magnetic fields of neutron stars as consisting of a long term power-law decay modulated by short term small amplitude oscillations. Our model prediction...
astro-ph_HE
On the Tidal Capture of White Dwarfs by Intermediate-mass Black Holes in Dense Stellar Environments: Intermediate-mass black holes (IMBHs) are the missing link between stellar-mass and supermassive black holes, widely believed to reside in at least some dense star clusters, but not yet observed directly. Tidal disrup...
astro-ph_HE
Radio Evolution of Supernova Remnants Including Non-linear Particle Acceleration: Insights from Hydrodynamic Simulations: We present a model for the radio evolution of supernova remnants (SNRs) obtained by using three-dimensional (3D) hydrodynamic simulations, coupled with nonlinear kinetic theory of cosmic ray (CR) ...
astro-ph_HE
Collective excitations in neutron-star crusts: We explore the spectrum of low-energy collective excitations in the crust of a neutron star, especially in the inner region where neutron-proton clusters are immersed in a sea of superfluid neutrons. The speeds of the different modes are calculated systematically from the ...
astro-ph_HE
Meeting the Challenge from Bright and Fast Gamma-Ray Flares of 3C 279: Bright and fast gamma-ray flares with hard spectra have been recently detected from the blazar 3C 279, with apparent GeV luminosities up to $10^{49}$ erg/s. The source is observed to flicker on timescales of minutes with no comparable optical-UV cou...
astro-ph_HE
A report on the type II X-ray burst from SMC X-1: We study RXTE PCA data for the high mass X-ray binary source SMC X-1 between 2003-10 and 2003-12 when the source was in high states. The source is found to be frequently bursting which can be seen as flares in lightcurves on an average of one in every 800 s, with an ave...
astro-ph_HE
Optical Spectral Variations of a Large Sample of Fermi Blazars: We have investigated the optical spectral behavior of a large sample of Fermi blazars (40 FSRQs and 13 BL Lacs), and found two new universal optical spectral behaviors. In the low state the optical spectrum gradually becomes softer (steeper) or harder (fla...
astro-ph_HE
Radio surface fluctuations in radio relics: Recent observations have revealed detailed structures of radio relics in a wide range of frequencies. In this work, we perform three-dimensional magnetohydrodynamical simulations of merger shocks propagating through a turbulent magnetized intracluster medium, and employ on-th...
astro-ph_HE
Cosmic-ray electron transport in the galaxy M 51: Context. Indirect observations of the cosmic-ray electron (CRE) distribution via synchrotron emission is crucial for deepening the understanding of the CRE transport in the interstellar medium, and in investigating the role of galactic outflows. Aims. In this paper, w...
astro-ph_HE
When and where did GW150914 form?: The recent LIGO detection of gravitational waves (GW150914), likely originating from the merger of two $\sim 30 M_\odot$ black holes suggests progenitor stars of low metallicity ($[Z/Z_\odot] \lesssim 0.3$), constraining when and where the progenitor of GW150914 may have formed. We co...
astro-ph_HE
Thermal synchrotron radiation from RRMHD simulations of the double tearing mode reconnection - Application to the Crab flares: We study the magneto-hydrodynamic tearing instability occurring in a double current sheet configuration when a guide field is present. This is investigated by means of resistive relativistic ...
astro-ph_HE
Gamma Rays From Blazars: Blazars are high-energy engines providing us natural laboratories to study particle acceleration, relativistic plasma processes, magnetic field dynamics, black hole physics. Key informations are provided by observations at high-energy (in particular by Fermi/LAT) and very-high energy (by Cheren...
astro-ph_HE
Effects of nuclear matter and composition in core-collapse supernovae and long-term proto-neutron star cooling: We study the influence of hot and dense matter in core-collapse supernovae by adopting up-to-date nuclear equation of state (EOS) based on the microscopic nuclear many-body frameworks. We explore effects of...
astro-ph_HE
The 999th Swift gamma-ray burst: Some like it thermal: We present a multiwavelength study of GRB 151027A. This is the 999th GRB detected by the Swift satellite and it has a densely sampled emission in the X-ray and optical band and has been observed and detected in the radio up to 140 days after the prompt. The multiwa...
astro-ph_HE
Time-resolved Spectral Study Of Fermi GRBs Having Single Pulses: We analyze gamma-ray bursts (GRBs) detected by \textit{Fermi}/Gamma-Ray Burst Monitor (GBM) and having single pulse. We fit the light curves with a model having exponential rise and decay parts. We perform a detailed time-resolved spectroscopy using four ...
astro-ph_HE
Deep Chandra observations of Pictor A: We report on deep Chandra observations of the nearby broad-line radio galaxy Pictor A, which we combine with new Australia Telescope Compact Array (ATCA) observations. The new X-ray data have a factor 4 more exposure than observations previously presented and span a 15-year time b...
astro-ph_HE
Observations of V404 Cygni during the 2015 outburst by the Nasu telescope array at 1.4 GHz: Waseda University Nasu telescope array is a spatial fast Fourier transform (FFT) interferometer consisting of eight linearly aligned antennas with 20 m spherical dishes. This type of interferometer was developed to survey tran...
astro-ph_HE
Merging White Dwarfs and Thermonuclear Supernovae: Thermonuclear supernovae result when interaction with a companion reignites nuclear fusion in a carbon-oxygen white dwarf, causing a thermonuclear runaway, a catastrophic gain in pressure, and the disintegration of the whole white dwarf. It is usually thought that fusi...
astro-ph_HE
Vortex Pinning in Neutron Stars, Slip-stick Dynamics, and the Origin of Spin Glitches: We study pinning and unpinning of superfluid vortices in the inner crust of a neutron star using 3-dimensional dynamical simulations. Strong pinning occurs for certain lattice orientations of an idealized, body-centered cubic latti...
astro-ph_HE
Searching for energy-resolved quasi-periodic oscillations in AGN: X-ray quasi-periodic oscillations (QPOs) in AGN allow us to probe and understand the nature of accretion in highly curved space-time, yet the most robust form of detection (i.e. repeat detections over multiple observations) has been limited to a single s...
astro-ph_HE
Searching for TeV emission from GRBs: the status of the H.E.S.S. GRB programme: H.E.S.S. is an array of five Imaging Atmospheric Cherenkov Telescopes (IACTs) located 1800 m above sea level in the Khomas Highland of Namibia and is sensitive to very-high-energy (VHE) gamma rays between tens of GeV to tens of TeV. The v...
astro-ph_HE
EAS optical Cherenkov signatures of tau neutrinos for space and suborbital detectors: Multi-messenger observations of transient astrophysical sources have the potential to characterize the highest energy accelerators and the most extreme environments in the Universe. Detection of neutrinos, in particular tau neutrino...
astro-ph_HE
Kink-driven magnetic reconnection in relativistic jets: consequences for X-ray polarimetry of BL Lacs: We investigate with relativistic MHD simulations the dissipation physics of BL Lac jets, by studying the synchrotron polarization signatures of particles accelerated by the kink instability in a magnetically-dominat...
astro-ph_HE
The inner knot of the Crab nebula: We model the inner knot of the Crab Nebula as a synchrotron emission coming from the non-spherical MHD termination shock of relativistic pulsar wind. The post-shock flow is mildly relativistic; as a result the Doppler-beaming has a strong impact on the shock appearance. The model can ...
astro-ph_HE
Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow: Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy...
astro-ph_HE
Associated molecular and atomic clouds with X-ray shell of superbubble 30 Doradus C in the LMC: 30 Doradus C is a superbubble which emits the brightest nonthermal X- and TeV gamma-rays in the Local Group. In order to explore detailed connection between the high energy radiation and the interstellar medium, we have ca...
astro-ph_HE
Effect of dark matter on the shadow of a distorted and deformed compact object: This work investigates observational properties, namely the shadow and photon ring structure, of emission profiles originated near compact objects. In particular, we consider a distorted and deformed compact object characterized by quadru...
astro-ph_HE
Progenitor, environment, and modelling of the interacting transient, AT 2016jbu (Gaia16cfr): We present the bolometric lightcurve, identification and analysis of the progenitor candidate, and preliminary modelling of AT2016jbu (Gaia16cfr). We find a progenitor consistent with a $\sim$22--25~$M_{\odot}$ yellow hypergi...
astro-ph_HE
Supernova Search with the AMANDA / IceCube Detectors: Since 1997 the neutrino telescope AMANDA at the geographic South Pole has been monitoring our Galaxy for neutrino bursts from supernovae. Triggers were introduced in 2004 to submit burst candidates to the Supernova Early Warning System SNEWS. From 2007 the burst sea...
astro-ph_HE
The glitches and rotational history of the highly energetic young pulsar PSR J0537$-$6910: We present a timing and glitch analysis of the young X-ray pulsar PSR J0537$-$6910, located within the Large Magellanic Cloud, using 13 years of data from the now decommissioned Rossi X-ray Timing Explorer. Rotating with a spin...
astro-ph_HE
X-ray emission of contact binary variables within 1 kpc: By assembling the largest sample to date of X-ray emitting EW-type binaries (EWXs), we carried out correlation analyses for the X-ray luminosity log$L_{\textrm{X}}$, and X-ray activity level log($L_{\textrm{X}}$/$L_{\textrm{bol}}$) versus the orbital period $P$ a...
astro-ph_HE
High Resolution X-ray Spectroscopy of the Seyfert 1, Mrk 1040. Revealing the Failed Nuclear Wind with Chandra: High resolution X-ray spectroscopy of the warm absorber in the nearby X-ray bright Seyfert 1 galaxy, Mrk 1040 is presented. The observations were carried out in the 2013-2014 timeframe using the Chandra High...
astro-ph_HE
Extremal energy shifts of radiation from a ring near a rotating black hole: Radiation from a narrow circular ring shows a characteristic double-horn profile dominated by photons having energy around the maximum or minimum of the allowed range, i.e. near the extremal values of the energy shift. The energy span of a sp...
astro-ph_HE
Gamma-Ray and X-Ray Observations of the Periodic-Repeater FRB 180916 During Active Phases: FRB 180916 is a most intriguing source at 150 Mpc distance capable of producing repeating fast radio bursts with a periodic 16.35 day temporal pattern. We report on the X-ray and $\gamma$-ray observations of FRB 180916 obtained...
astro-ph_HE
Equations of state for supernovae and compact stars: We review various theoretical approaches for the equation of state (EoS) of dense matter, relevant for the description of core-collapse supernovae, compact stars and compact star mergers. The emphasis is put on models that are applicable to all of these scenarios. Su...
astro-ph_HE
Neural Simulation-Based Inference of the Neutron Star Equation of State directly from Telescope Spectra: Neutron stars provide a unique opportunity to study strongly interacting matter under extreme density conditions. The intricacies of matter inside neutron stars and their equation of state are not directly visible...
astro-ph_HE
Cosmic-ray spectral anomaly at GeV-TeV energies as due to re-acceleration by weak shocks in the Galaxy: Recent cosmic-ray measurements by the ATIC, CREAM and PAMELA experiments have found an apparent hardening of the energy spectrum at TeV energies. Although the origin of the hardening is not clearly understood, poss...
astro-ph_HE
A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states: The nearby type-II AGN 1ES1927+654 went through a violent changing-look (CL) event beginning December 2017 during which the optical and UV fluxes increased by four magnitudes ove...
astro-ph_HE
Fermi Large Area Telescope observations of Local Group galaxies: Detection of M31 and search for M33: Cosmic rays (CRs) can be studied through the galaxy-wide gamma-ray emission that they generate when propagating in the interstellar medium. The comparison of the diffuse signals from different systems may inform us a...
astro-ph_HE
Variations of the physical parameters of the blazar Mrk 421 based on the analysis of the spectral energy distributions: We report on the variations of the physical parameters of the jet observed in the blazar Mrk 421, and discuss the origin of X-ray flares in the jet, based on the analysis of the several spectral ene...
astro-ph_HE
Accretion-powered pulsations in an apparently quiescent neutron star binary: Accreting millisecond X-ray pulsars are an important subset of low-mass X-ray binaries in which coherent X-ray pulsations can be observed during occasional, bright outbursts (X-ray luminosity $L_X\sim 10^{36}$ erg s$^{-1}$). These pulsations...
astro-ph_HE
Indications of Negative Evolution for the Sources of the Highest Energy Cosmic Rays: Using recent measurements of the spectrum and chemical composition of the highest energy cosmic rays, we consider the sources of these particles. We find that the data strongly prefers models in which the sources of the ultra-high en...
astro-ph_HE
Stellar wind accretion and accretion disk formation: applications to neutron star high mass X-ray binaries: Recent X-ray observations have revealed the complexity and diversity of high-mass X-ray binaries (HMXBs). This diversity challenges a classical understanding of the accretion process onto the compact objects. I...
astro-ph_HE
Stability of three-dimensional relativistic jets: implications for jet collimation: The stable propagation of jets in FRII sources is remarkable if one takes into account that large-scale jets are subjected to potentially highly disruptive three-dimensional (3D) Kelvin-Helmholtz instabilities. Numerical simulations c...
astro-ph_HE
Non-parametric Bayesian reconstruction of Galactic magnetic fields using Information Field Theory: The inclusion of line-of-sight information in ultra-high energy cosmic ray backtracking: (abridged) Ultra-high energy cosmic rays (UHECRs) are extremely energetic charged particles with energies surpassing $10^{18}$ e...
astro-ph_HE
Mass of intermediate black hole in the source M82 X-1 restricted by models of twin high-frequency quasi-periodic oscillations: We apply the relativistic precession (RP) model with its variants and the resonance epicyclic model with its variants, based on the frequencies of the geodesic epicyclic motion in the field o...
astro-ph_HE
Determining the optimal locations for shock acceleration in magnetohydrodynamical jets: Observations of relativistic jets from black holes systems suggest that particle acceleration often occurs at fixed locations within the flow. These sites could be associated with critical points that allow the formation of standi...
astro-ph_HE