Latest in astro-ph.he

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Comparing an analytical spacetime metric for a merging binary to a fully non-linear numerical evolution using curvature scalarsFeb 08 2018We introduce a new geometrically invariant prescription for comparing two different spacetimes based on geodesic deviation. We use this method to compare a family of recently introduced analytical spacetime representing inspiraling black-hole binaries ... More
Towards the First Catalog of Fermi-LAT sources below 100 MeVFeb 08 2018Previous analyses of point sources in the gamma-ray range were done either below 30 MeV or above 100 MeV. Below 30 MeV, the imaging Compton telescope (COMPTEL) onboard NASA's Compton Gamma-Ray Observatory detected 26 steady sources in the energy range ... More
Polynomial approximation of the Lense-Thirring rigid precession frequencyFeb 08 2018We propose a polynomial approximation of the global Lense-Thirring rigid precession frequency to study low frequency quasi-periodic oscillations around spinning black holes. This high-performing approximation allows to determine the expected frequencies ... More
Selfgravitating axially symmetric disks in general-relativistic rotationFeb 08 2018We integrate numerically axially symmetric stationary Einstein equations describing self-gravitating disks around spinless black holes. The numerical scheme is based on a method developed by Shibata, but contains important new ingredients. We derive a ... More
The Crab pulsar: ion-proton plasma and high-frequency radio spectrumFeb 08 2018Salient features of the remarkable band structure seen in the high-frequency interpulse of the Crab pulsar are summarized. It is argued that its source must lie in a current sheet, probably coincident with the open-closed magnetosphere separatrix, and ... More
The Origin of Recombining Plasma and the Detection of the Fe-K Line in the Supernova Remnant W28Feb 08 2018Overionized recombining plasmas (RPs) have been discovered from a dozen of mixed- morphology (MM) supernova remnants (SNRs). However their formation process is still under debate. As pointed out by many previous studies, spatial variations of plasma temperature ... More
A Deep X-ray View of the Synchrotron-Dominated Supernova Remnant G330.2+1.0Feb 08 2018We present moderately deep (125 ks) {\it XMM-Newton} observations of supernova remnant G330.2$+$1.0. This remnant is one of only a few known that fall into "synchrotron-dominated" category, with the emission almost entirely dominated by a nonthermal continuum. ... More
The MRI imprint on the Short-GRB JetsFeb 08 2018Short gamma ray bursts are presumably results of binary neutron star mergers, which lead to the formation of a stellar mass black hole, surrounded by a remnant matter. The strong magnetic fields help collimate jets of plasma, launched along the axis of ... More
Gamma-rays in the radio galaxy 3C 84: A complex situationFeb 08 20183C 84 is a nearby Active Galactic Nucleus (AGN) that is unique in that is believed that we are observing near the true jet launching region - unlike blazars. The source is active in Gamma rays and has been detected with Fermi since its launch in 2008, ... More
KVN observations suggest multiple $γ$-ray emission regions in 3C 84Feb 08 20183C 84 (NGC 1275) is a well-studied mis-aligned Active Galactic Nucleus (AGN), which has been active in Gamma rays since at least 2008. We have monitored the source at four wavelengths (14 mm, 7 mm, 3 mm and 2 mm) using the Korean VLBI network (KVN) since ... More
Does the black hole shadow probe the event horizon geometry?Feb 07 2018There is an exciting prospect of obtaining the shadow of astrophysical black holes (BHs) in the near future with the Event Horizon Telescope. As a matter of principle, this justifies asking how much one can learn about the BH horizon itself from such ... More
Penetration of cosmic rays into dense molecular clouds: role of diffuse envelopeFeb 07 2018A flux of cosmic rays (CRs) propagating through a diffuse ionized gas can excite MHD waves, thus generating magnetic disturbances. We propose a generic model of CR penetration into molecular clouds through their diffuse envelopes, and identify the leading ... More
The Low-Frequency Radio Eclipses of the Black Widow Pulsar J1810+1744Feb 07 2018We have observed and analysed the eclipses of the black widow pulsar J1810+1744 at low radio frequencies. Using LOw-Frequency ARray (LOFAR) and Westerbork Synthesis Radio Telescope observations between 2011--2015 we have measured variations in flux density, ... More
Detecting Stellar Lensing of Gravitational Waves with Ground-Based ObservatoriesFeb 07 2018We investigate the ability of ground based gravitational wave observatories to detect gravitational wave lensing events caused by stellar mass lenses. We show that LIGO and Virgo possess the sensitivities required to detect lenses with masses as small ... More
Supernova Neutrino Neutrino AstronomyFeb 07 2018Modern neutrino facilities will be able to detect a large number of neutrinos from the next Galactic supernova. We investigate the viability of the triangulation method to locate a core-collapse supernova by employing the neutrino arrival time differences ... More
The merger of two compact stars: a tool for dense matter nuclear physicsFeb 07 2018We discuss the different signals, in gravitational and electromagnetic waves, emitted during the merger of two compact stars. We will focus in particular on the possible contraints that those signals can provide on the equation of state of dense matter. ... More
On the formation of neutron stars via accretion-induced collapse in binariesFeb 07 2018Although most neutron stars are believed to form in core-collapse supernovae, some fraction of them may form in less well-known sites. We investigate evolutionary pathways leading to neutron stars formed through the collapse of oxygen-neon white dwarf ... More
On the formation of neutron stars via accretion-induced collapse in binariesFeb 07 2018Feb 08 2018Although most neutron stars are believed to form in core-collapse supernovae, some fraction of them may form in less well-known sites. We investigate evolutionary pathways leading to neutron stars formed through the collapse of oxygen-neon white dwarf ... More
Hadronic model for the non-thermal radiation from the binary system AR~ScorpiiFeb 07 2018AR Scorpii is a close binary system containing a rotation powered white dwarf and a low mass M type companion star. This system shows non-thermal emission extending up to the X-ray energy range. We consider hybrid (lepto-hadronic) and pure hadronic models ... More
Why is Interstellar Object 1I/2017 U1 (`Oumuamua) Rocky, Tumbling and Very Prolate?Feb 07 2018The recently discovered first interstellar object 1I/2017 U1 (`Oumuamua) has brightness that varies by a factor of 10, a range greater than that of any Solar System asteroid, a spectrum characteristic of Type D asteroids, and no evidence of evaporating ... More
Magnetohydrodynamic Turbulence in the Plasmoid-Mediated RegimeFeb 06 2018Magnetohydrodynamic turbulence and magnetic reconnection are ubiquitous in astrophysical environments. In most situations, these processes do not occur in isolation, but interact with each other. This renders a comprehensive theory of these processes ... More
Constraining Type Ia Supernova Progenitor Scenarios with Extremely Late-time Photometry of Supernova SN 2013aaFeb 06 2018We present Hubble Space Telescope observations and photometric measurements of the Type Ia supernova (SN Ia) SN 2013aa 1500 days after explosion. At this epoch, the luminosity is primarily dictated by the amounts of radioactive ${}^{57}\textrm{Co}$ and ... More
Constraining Type Ia Supernova Progenitor Scenarios with Extremely Late-time Photometry of Supernova SN 2013aaFeb 06 2018Feb 08 2018We present Hubble Space Telescope observations and photometric measurements of the Type Ia supernova (SN Ia) SN 2013aa 1500 days after explosion. At this epoch, the luminosity is primarily dictated by the amounts of radioactive ${}^{57}\textrm{Co}$ and ... More
The First Hours of the GW170817 Kilonova and the Importance of Early Optical and Ultraviolet Observations for Constraining Emission ModelsFeb 06 2018The kilonova associated with GW170817 displayed early blue emission which has been interpreted as a signature of either radioactive decay in low-opacity ejecta, relativistic boosting of radioactive decay in high-velocity ejecta, the cooling of material ... More
LeMMINGs. I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and coresFeb 06 2018We present the first data release of high-resolution ($\leq0.2$ arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies which are active ... More
On the Missing Energy Puzzle of Tidal Disruption EventsFeb 06 2018Recent optical/UV transient surveys have been successful in finding tidal disruption events (TDEs), where a star is disrupted by the tidal gravity of a supermassive black hole. For the majority of the TDE candidates, the observed energy in the optical/UV ... More
Synergies of THESEUS with the SKA: a brief reportFeb 06 2018Feb 07 2018We present a short report on the main synergies between Theseus and SKA in the study of high-redshift transients and we summarize a few more aspects where Theseus and SKA can contribute to explore fundamental physics in the universe.
Systematic Analysis of Low/Hard State RXTE Spectra of GX 339-4 to Constrain the Geometry of the SystemFeb 06 2018One of the popular models for the low/hard state of Black Hole Binaries is that the standard accretion disk is truncated and the hot inner region produces via Comptonization, the hard X-ray flux. This is supported by the value of the high energy photon ... More
The redshift of the BL Lac object TXS 0506+056Feb 06 2018The bright BL Lac object TXS 0506+056 is a most likely counterpart of the IceCube neutrino event EHE 170922A. The lack of this redshift prevents a comprehensive understanding of the modeling of the source. We present high signal-to-noise optical spectroscopy, ... More
IGR J19294+1816: a new Be-X ray binary revealed through infrared spectroscopyFeb 06 2018The aim of this work is to characterize the counterpart to the INTEGRAL High Mass X-ray Binary candidate IGR J19294+1816 so as to establish its true nature. We obtained H band spectra of the selected counterpart acquired with the NICS instrument mounted ... More
Rotational phase dependence of magnetar burstsFeb 06 2018The trigger for the short bursts observed in $\gamma$-rays from many magnetar sources remains unknown. One particular open question in this context is the localization of burst emission to a singular active region or a larger area across the neutron star. ... More
GRB 151027B - large-amplitude late-time radio variabilityFeb 06 2018Deriving physical parameters from gamma-ray burst afterglow observations remains a challenge, even now, 20 years after the discovery of afterglows. The main reason for the lack of progress is that the peak of the synchrotron emission is in the sub-mm ... More
Characterizing long-term optical, ultraviolet and X-ray variability in different activity states of OJ 287Feb 06 2018We have studied long-term optical, ultraviolet (UV) and X-ray observations of OJ 287 collected with the UVOT and XRT instruments mounted on board the Swift satellite to quantify spectral and temporal variability patterns observed during different activity ... More
Effect of differential cross section in Breit-Wheeler pair beamingFeb 06 2018The pair beaming in the Breit-Wheeler (BW) process is investigated. We examine the effect of the BW differential cross section on pair angular and energy distributions. Although, this study is relevant for laser induced intense gamma-ray source collisions ... More
Impact of medium modification of the nucleon weak and electromagnetic form factors on the neutrino mean free path in dense matterFeb 06 2018Impact of the in-medium modified nucleon weak and electromagnetic form factors on the neutrino mean free path in dense matter is studied by considering both the weak and electromagnetic interactions of neutrinos with the constituents of the matter. A ... More
PALFA Discovery of a Highly Relativistic Double Neutron Star BinaryFeb 05 2018We report the discovery and initial follow-up of a double neutron star (DNS) system, PSR J1946$+$2052, with the Arecibo L-Band Feed Array pulsar (PALFA) survey. PSR J1946$+$2052 is a 17-ms pulsar in a 1.88-hour, eccentric ($e \, =\, 0.06$) orbit with ... More
The Maveric Survey: a Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10Feb 05 2018We present the discovery and characterization of a radio-bright binary in the Galactic globular cluster M10. First identified in deep radio continuum data from the Karl G. Jansky Very Large Array, M10-VLA1 has a flux density of $27\pm4$ $\mu$Jy at 7.4 ... More
A multi-messenger analysis of neutron star mergersFeb 05 2018The merger of two neutron stars is a very complex process. In order to disentangle the various steps through which it takes place it is mandatory to examine all the signals we can detect: gravitational waves and electromagnetic waves, in a huge spectrum ... More
High redshift constraints on dark energy models from the $E_{\rm p,i}$ -- $E_{\rm iso}$ correlation in GRBsFeb 05 2018Here we test different models of dark energy beyond the standard cosmological constant scenario. We start considering the CPL parameterization of the equation of state (EOS), then we consider a dark energy scalar field (Quintessense). Finally we consider ... More
Revisiting the Statistics of X-ray Flares in Gamma-ray BurstsFeb 05 2018The statistics of X-ray flares in the afterglow of gamma-ray bursts (GRBs) have been studied extensively without considering the possible different origins of each flare. By satisfying six observational criteria, we find a sample composed of $16$ long ... More
Observing strategy of the THESEUS missionFeb 05 2018We will discuss the observing strategy of the Transient High Energy Sky and Early Universe Surveyor (THESEUS) mission proposed to ESA as a response to the M5 call for proposals. The description of THESEUS and its science goals can be found in the white ... More
Role of THESEUS in Understanding the Radiation Mechanism of GRB Prompt EmissionFeb 05 2018The radiation process of GRB prompt emission remains highly debated till date. Though a smoothly broken powerlaw function like Band provides an excellent fit to most of the cases, a spectrum with a broad top or double hump structure has emerged recently ... More
Gamma-ray bursts as tracers of star-formation rate and metallicity evolution with THESEUSFeb 05 2018The class of long gamma-ray bursts (LGRBs) is associated with the collapse of the most massive stars, making them a tool to investigate star formation in the early Universe. Furthermore, thanks to their exceptional brightness, LGRB afterglows can be used ... More
Synergies between the Cherenkov Telescope Array and THESEUSFeb 05 2018The Cherenkov Telescope Array (CTA) is designed to be the next major observatory operating in the Very High Energy (VHE, $\gtrsim 100$ GeV) gamma-ray band. It will build on the imaging atmospheric Cherenkov technique but will go much further in terms ... More
THESEUS and Gamma-Ray Bursts: a valuable contribution to the understanding of prompt emissionFeb 05 2018Recent advances in fitting prompt emission spectra in gamma-ray bursts (GRBs) are boosting our understanding of the still elusive origin of this radiation. These progresses have been possible thanks to a more detailed analysis of the low-energy part ($<$\,100\,keV) ... More
The link between short Gamma-ray bursts and Gravitational Waves: perspectives for the THESEUS missionFeb 05 2018The knowledge of the class of short Gamma-Ray Bursts (GRBs), characterised by a duration of the gamma-ray emission $\leq 2$ s, experienced an impressive boost in the last decade. In particular, the discovery of short GRB afterglows in 2005 with Swift ... More
Synergy between THESEUS and E-ELTFeb 05 2018The Transient High Energy Sky and Early Universe Surveyor (THESEUS) is a space mission concept aimed at exploiting Gamma-Ray Bursts for investigating the early Universe and at providing a substantial advancement of multi-messenger and time-domain astrophysics. ... More
The THESEUS Workshop 2017Feb 05 2018The Transient High-Energy Sky and Early Universe Surveyor (THESEUS) is a mission concept developed in the last years by a large European consortium, with interest in prospective participation by research groups in USA and other non-European countries. ... More
PISCO: The Pmas/ppak Integral-field Supernova hosts COmpilationFeb 05 2018We present the Pmas/ppak Integral-field Supernova hosts COmpilation (PISCO) which comprises Integral Field Spectroscopy (IFS) of 232 supernova (SN) host galaxies, that hosted 272 SNe, observed over several semesters with the 3.5m telescope at the Calar ... More
A Global Photoionization Response to Prompt Emission and Outliers: Different Origin of Long Gamma-ray Bursts?Feb 05 2018By using the line ratio \ion{C}{4}$\lambda1549$/\ion{C}{2}$\lambda1335$ as a tracer of ionization ratio of the interstellar medium (ISM) illuminated by a long gamma-ray burst (LGRB), we identify a global photoionization response of the ionization ratio ... More
FERMI transient J1544-0649: a flaring radio-weak BL LacFeb 04 2018On May 15th, 2017, the \emph{FERMI}/LAT gamma-ray telescope observed a transient source not present in any previous high-energy catalogue: J1544-0649. It was visible for two consecutive weeks, with a flux peak on May 21st. Subsequently observed by a \emph{Swift}/XRT ... More
Gravitational Lensing of a star by a rotating black holeFeb 02 2018The gravitational lensing of a finite star moving around a rotating Kerr black hole has been numerically calculated. Calculations for the direct image of the star and for the first and second light echoes have been performed for the star moving with an ... More
Maximally Rotating Supermassive Stars at the Onset of Collapse: The Perturbative Effects of Gas Pressure, Magnetic Fields, Dark Matter and Dark EnergyFeb 02 2018The discovery of quasars at increasingly large cosmological redshifts may favor "direct collapse" as the most promising evolutionary route to the formation of supermassive black holes. In this scenario, supermassive black holes form when their progenitors ... More
Numerically solving the relativistic Grad-Shafranov equation in Kerr spacetimes: Numerical techniquesFeb 02 2018The study of the electrodynamics of static, axisymmetric and force-free Kerr magnetospheres relies vastly on solutions of the so called relativistic Grad-Shafranov equation (GSE). Different numerical approaches to the solution of the GSE have been introduced ... More
On the Nature of the High-Energy Rollover in 1H 0419-577Feb 02 2018A NuSTAR/Swift observation of the luminous Seyfert 1 galaxy 1H 0419-577 taken during 2015 reveals one of the most extreme high energy cut-offs observed to date from an AGN - an origin due to thermal Comptonization would imply a remarkably low coronal ... More
Survey of astrophysical conditions in neutrino-driven supernova ejecta nucleosynthesisFeb 01 2018Core-collapse supernovae produce elements between Fe and Ag depending on the properties of the ejected matter. Despite the fast progress in supernova simulations in the last decades, there are still uncertainties in the astrophysical conditions. In this ... More
MHD simulations of resistive viscous accretion disk around millisecond pulsarFeb 01 2018We perform MHD simulations of a thin resistive and viscous accretion disk around a neutron star with the surface dipolar magnetic field of 10$^8$ Gauss. The system evolution is followed during the interval of 500 millisecond pulsar rotations. Matter is ... More
Polarimetry and Spectroscopy of the `Oxygen Flaring' DQ Herculis-like nova: V5668 Sagittarii (2015)Feb 01 2018Classical novae are eruptions on the surface of a white dwarf in a binary system. The material ejected from the white dwarf surface generally forms an axisymmetric shell of gas and dust around the system. The three-dimensional structure of these shells ... More
The zenithal 4-m International Liquid Mirror Telescope: a unique facility for supernova studiesFeb 01 2018The 4-m International Liquid Mirror Telescope (ILMT) will soon become operational at the newly developed Devasthal observatory near Nainital (Uttarakhand, India). Coupled with a 4k $\times$ 4k pixels CCD detector and TDI optical corrector, it will reach ... More
HST spectrum and timing of the ultra-compact X-ray binary candidate 47 Tuc X9Feb 01 2018To confirm the nature of the donor star in the ultra-compact X-ray binary candidate 47 Tuc X9, we obtained optical spectra (3,000$-$10,000 {\AA}) with the Hubble Space Telescope / Space Telescope Imaging Spectrograph. We find no strong emission or absorption ... More
Kepler K2 observations of the transitional millisecond pulsar PSR J1023+0038Jan 31 2018For 80 days in 2017, the Kepler Space Telescope continuously observed the transitional millisecond pulsar system PSR J1023$+$0038 in its accreting state. We present analyses of the 59-second cadence data, focusing on investigations of the orbital light ... More
Multi-wavelength Polarimetry of Isolated Neutron StarsJan 31 2018Isolated Neutron Stars are known to be endowed with extreme magnetic fields, whose maximum intensity ranges from 10^12 to 10^15 G, which permeates their magnetospheres. Their surrounding environment is also strongly magnetised, especially in the compact ... More
Surface and core detonations in rotating white dwarfsJan 31 2018The feasibility of the Double Detonation mechanism, -a surface Helium-detonation followed by the complete carbon detonation of the core-, in a rotating white dwarf with a mass $\simeq 1 M_{\odot}$ is studied using three-dimensional hydrodynamic simulations. ... More
Ten Years of PAMELA in SpaceJan 31 2018The PAMELA cosmic ray detector was launched on June 15th 2006 on board the Russian Resurs-DK1 satellite, and during ten years of nearly continuous data-taking it has observed new interesting features in cosmic rays (CRs). In a decade of operation it has ... More
Light rays and wave fronts in strong gravityJan 30 2018Accretion onto black holes often proceeds via an accretion disk or a temporary disk-like pattern. Variability features observed in light curves as well as theoretical models of accretion flows suggest that accretion disks tend to be inhomogeneous -- variety ... More
Stellar Tidal Disruption Events in General RelativityJan 30 2018A tidal disruption event (TDE) ensues when a star passes too close to the supermassive black hole (SMBH) in a galactic center and is ripped apart by the tidal field of the SMBH. The gaseous debris produced in a TDE can power a bright electromagnetic flare ... More
Probing dissipation mechanisms in BL Lac jets through X-ray polarimetryJan 30 2018The dissipation of energy flux in blazar jets plays a key role in the acceleration of relativistic particles. Two possibilities are commonly considered for the dissipation processes, magnetic reconnection -- possibly triggered by instabilities in magnetically-dominated ... More
Discovery of three new millisecond pulsars in Terzan 5Jan 30 2018We report on the discovery of three new millisecond pulsars (namely J1748-2446aj, J1748-2446ak and J1748-2446al) in the inner regions of the dense stellar system Terzan 5. These pulsars have been discovered thanks to a method, alternative to the classical ... More
X-Ray and Optical Properties of Black Widows and RedbacksJan 30 2018Black widows and redbacks are binary systems consisting of a millisecond pulsar in a close binary with a companion having matter driven off of its surface by the pulsar wind. X-rays due to an intra-binary shock have been observed from many of these systems, ... More
Yet another UFO in the X-ray spectrum of a high-z lensed QSOJan 30 2018Ultra-fast outflows (UFO) appear to be common in local active galactic nuclei (AGN) and may be powerful enough ($\dot{E}_{kin}$$\geq$1\% of L$_{bol}$) to effectively quench the star formation in their host galaxies. To test feedback models based on AGN ... More
NuSTAR view of the central region of M 31Jan 30 2018Our neighbouring large spiral galaxy, the Andromeda galaxy (M 31 or NGC 224), is an ideal target to study the X-ray source population of a nearby galaxy. NuSTAR observed the central region of M 31 in 2015 and allows studying the population of X-ray point ... More
Depth of Ultra High Energy Cosmic Ray Induced Air Shower Maxima Measured by the Telescope Array Black Rock and Long Ridge FADC Fluorescence Detectors and Surface Array in Hybrid ModeJan 29 2018The Telescope Array observatory utilizes fluorescence detectors and surface detectors to observe air showers produced by ultra high energy cosmic rays in the Earth's atmosphere. Cosmic ray events observed in this way are termed hybrid data. The depth ... More
The energetics of AGN radiation pressure-driven outflowsJan 29 2018The increasing observational evidence of galactic outflows is considered as a sign of active galactic nucleus (AGN) feedback in action. However, the physical mechanism responsible for driving the observed outflows remains unclear, and whether it is due ... More
Fermi-LAT Observation of Non-Blazar AGNsJan 29 2018We report on a detailed investigation of the $\gamma$-ray emission from 26 non-blazar AGNs based on the Fermi LAT data accumulated for 7 years. The photon index of non-blazar AGNs changes in the range of 1.84-2.86 and the flux varies from a few times ... More
Modeling the Multi-band Afterglow of GRB 060908 with the Double Power-Law Hard Electron Energy Spectrum ModelJan 28 2018Electrons accelerated in relativistic collisionless shocks are usually assumed to follow a power-law energy distribution with an index of $p$. Observationally, although most gamma-ray bursts (GRBs) have afterglows that are consistent with $p>2$, there ... More
Pinpointing astrophysical bursts of low-energy neutrinos embedded into the noiseJan 27 2018We propose a novel method to increase the probability of identifying impulsive astrophysical bursts of low-energy neutrinos. The proposed approach exploits the temporal structure differences between astrophysical bursts and background fluctuations and ... More
Improving r-process calculations for the rare-earth abundance peak via mass measurements at JYFLTRAPJan 26 2018Feb 01 2018The rare-earth peak in the $r$-process abundance pattern depends sensitively on both the astrophysical conditions and subtle changes in nuclear structure in the region. This work takes an important step elucidating the nuclear structure and reducing the ... More
Cosmic ray production in supernovaeJan 26 2018We give a brief review of the origin and acceleration of cosmic rays (CRs), emphasizing the production of CRs at different stages of supernova evolution by the first-order Fermi shock acceleration mechanism. We suggest that supernovae with trans-relativistic ... More
FBQS J1644+2619: multiwavelength properties and its place in the class of gamma-ray emitting Narrow Line Seyfert 1sJan 26 2018A small fraction of Narrow Line Seyfert 1s (NLSy1s) are observed to be gamma-ray emitters. Understanding the properties of these sources is of interest since the majority of NLSy1s are very different from typical blazars. Here, we present a multi-frequency ... More
A combined multiwavelength VLA/ALMA/Chandra study unveils the complex magnetosphere of the B-type star HR5907Jan 26 2018We present new radio/millimeter measurements of the hot magnetic star HR5907 obtained with the VLA and ALMA interferometers. We find that HR5907 is the most radio luminous early type star in the cm-mm band among those presently known. Its multi-wavelength ... More
Fully kinetic large scale simulations of the collisionless Magnetorotational instabilityJan 26 2018We present two-dimensional particle-in-cell (PIC) simulations of the fully kinetic collisionless magnetorotational instability (MRI) in weakly magnetized (high $\beta$) pair plasma. The central result of this numerical analysis is the emergence of a self-induced ... More
Correlating nonlinear properties with spectral states of RXTE data: Possible observational evidences for four different accretion modes around compact objectsJan 25 2018By analyzing the time series of RXTE/PCA data, the nonlinear variabilities of compact sources have been repeatedly established. Depending on the variation in temporal classes, compact sources exhibit different nonlinear features. Sometimes they show low ... More
Measuring the masses of Intermediate Polars with NuSTAR: V709 Cas, NY Lup and V1223 SgrJan 25 2018The X-ray spectra of intermediate polars can be modelled to give a direct measurement of white dwarf mass. Here we fit accretion column models to NuSTAR spectra of three intermediate polars; V709 Cas, NY Lup and V1223 Sgr in order to determine their masses. ... More
A near-infrared, optical and ultraviolet polarimetric and timing investigation of complex equatorial dusty structuresJan 25 2018Context. From stars to active galactic nuclei, many astrophysical systems are surrounded by an equatorial distribution of dusty material that are, in a number of cases, spatially unresolved even with cutting edge facilities. Aims. In this paper, we investigate ... More
ASASSN-15no: The Supernova that plays hide-and-seekJan 25 2018We report the results of our follow-up campaign of the peculiar supernova ASASSN-15no, based on optical data covering ~300 days of its evolution. Initially the spectra show a pure blackbody continuum. After few days, the HeI 5876 A transition appears ... More
Modeling the Multi-band Afterglow of GRB 060614: Further Evidence for a Double Power-Law Hard Electron Energy SpectrumJan 25 2018Electrons accelerated in relativistic collisionless shocks are usually assumed to follow a power-law energy distribution with an index of $p$. Observationally, although most gamma-ray bursts (GRBs) have afterglows that are consistent with $p>2$, there ... More
First release of high-redshift superluminous supernovae from the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA). II. Spectroscopic propertiesJan 24 2018We present Keck spectroscopic confirmation of three superluminous supernovae (SLSNe) at z = 1.851, 1.965 and 2.399 detected as part of the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA). The host galaxies have multi-band photometric redshifts consistent with ... More
First release of high-redshift superluminous supernovae from the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA). I. Photometric propertiesJan 24 2018We report our first discoveries of high-redshift supernovae from the Subaru HIgh-Z sUpernova CAmpaign (SHIZUCA), a transient survey using Subaru/Hyper Suprime-Cam. We report the discovery of three supernovae at spectroscopically-confirmed redshifts of ... More
Revival of the Fittest: Exploding Core-Collapse Supernovae from 12 to 25 M$_{\odot}$Jan 24 2018Jan 26 2018We present results of 2D axisymmetric core-collapse supernova simulations, employing the FORNAX code, of nine progenitor models spanning 12 to 25 M$_{\odot}$ and evolved over a 20,000-km grid. We find that four of the nine models explode with inelastic ... More
From the earliest pulses to the latest flares in long GRBsJan 24 2018The prompt emission of Gamma Ray Bursts extends from the early pulses observed in gamma-rays (>15 keV) to very late flares of X-ray photons (0.3-10 keV). The duration of prompt gamma-ray pulses is rather constant while the width of X-ray flares correlates ... More
Regularity of high energy photon events from gamma ray burstsJan 24 2018Feb 06 2018The effect of Quantum Gravity (QG) may bring a tiny light speed variation as $v(E)=c(1-E/E_{\rm LV})$, where $E$ is the photon energy and $E_{\rm LV}$ is a Lorentz violation scale. A remarkable regularity was suggested in previous studies to look for ... More
Constraints on two accretion disks centered on the equatorial plane of a Kerr SMBHJan 24 2018The possibility that two toroidal accretion configurations may be orbiting around a~super--massive Kerr black hole has been addressed. Such tori may be formed during different stages of the Kerr attractor accretion history. We consider the relative rotation ... More
QED Plasma at High TemperatureJan 24 2018We demonstrate that the early universe behaved as a relativistic QED (Quantum Electrodynamics) plasma around the nucleosynthesis time while the temperature of the universe was below the neutrino decoupling temperature in the early universe. QED coupling ... More
Evidence for Declination Dependence of Ultrahigh Energy Cosmic Ray Spectrum in the Northern HemisphereJan 24 2018The energy of the ultrahigh energy spectral cutoff was measured, integrating over the northern hemisphere sky, by the Telescope Array (TA) collaboration, to be $10^{19.78 \pm 0.06}$ eV, in agreement with the High Resolution Fly's Eye (HiRes) experiment, ... More
Matter-neutrino resonance in a multi-angle neutrino bulb modelJan 24 2018Simulations of neutrino flavor evolution in compact merger environments have shown that neutrino flavor, and hence nucleosynthesis, can be strongly affected by the presence of matter-neutrino resonances (MNRs), where there is a cancelation between the ... More
Simultaneous broadband observations and high-resolution X-ray spectroscopy of the transitional millisecond pulsar PSR J1023+0038Jan 23 2018We report on the first simultaneous XMM-Newton, NuSTAR and Swift observations of the transitional millisecond pulsar PSR J1023+0038 in the X-ray active state. Our multi-wavelength campaign allowed us to investigate with unprecedented detail possible spectral ... More
Uncertainties in radiative neutron-capture rates relevant to the $A\sim 80$ $r$-process peakJan 23 2018The rapid neutron-capture process ($r$-process) has for the first time been confirmed to take place in a neutron-star merger event. A detailed understanding of the rapid neutron-capture process is one of the holy grails in nuclear astrophysics. In this ... More
Persistent X-ray emission from ASASSN-15lh: pre-SLSN dense wind?Jan 23 2018Jan 29 2018The persistent soft X-ray emission at the location of the so-far most luminous supernova (SN), ASASSN-15lh (or SN 2015L), with $L \sim 10^{42} \rm erg~ s^{-1}$, is puzzling. We show that it can be explained by radiation from the SN-shock accelerated electrons ... More
GRS 1758-258: the first winged microquasarJan 23 2018The family links between radio galaxies and microquasars have been strongly strengthened thanks to a new common phenomenon: the presence of extended winged features. The first detection of such structures in a Galactic microquasar, recently reported in ... More
Pulsar glitch and nuclear EoS: Applicability of superfluid modelJan 22 2018In this contribution, we have made use of the contemporary equation of states (EOSs) for the complete neutron star structure, and confronted them with one particular glitch constrain for the crustal moment of inertia (MOI). We find that with these EOSs, ... More