Latest in astro-ph.he

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Limiting magnetic field for minimal deformation of a magnetised neutron starFeb 21 2019In this work we study the structure of neutron stars under the effect of a poloidal magnetic field and determine the limiting highest magnetic field intensity which still allows a satisfactory description of magnetic neutron stars in the spherical symmetry ... More
Report on Tests and Measurements of Hadronic Interaction Properties with Air ShowersFeb 21 2019We present a summary of recent tests and measurements of hadronic interaction properties with air showers. This report has a special focus on muon density measurements. Several experiments reported deviations between simulated and recorded muon densities ... More
The Energy Sources of Superluminous SupernovaeFeb 21 2019Supernovae (SNe) are the most brilliant optical stellar-class explosions. Over the past two decades, several optical transient survey projects discovered more than $\sim 100$ so-called superluminous supernovae (SLSNe) whose peak luminosities and radiated ... More
Inspiral of a Rotating Black Hole -- Magnetized Neutron Star Binary: Increasingly Charging and Electromagnetic EmissionFeb 21 2019The mergers of black hole (BH) -- neutron star (NS) binaries have been one of the most interesting topics, because such events have been thought to possibly produce multi-messenger signals including gravitational waves and broadband electromagnetic (EM) ... More
A multi-wavelength analysis of a collection of short-duration GRBs observed between 2012-2015Feb 21 2019We investigate the prompt emission and the afterglow properties of short duration gamma-ray burst (sGRB) 130603B and another eight sGRB events during 2012-2015, observed by several multi-wavelength facilities including the GTC 10.4m telescope. Prompt ... More
Pulsar Radio Emission Mechanism: Radio Nanoshots as a Low Frequency Afterglow of Relativistic Magnetic ReconnectionFeb 20 2019In this Letter we propose that coherent radio emission of Crab, other young energetic pulsars, and millisecond pulsars is produced in the magnetospheric current sheet beyond the light cylinder. We carry out global and local two-dimensional kinetic plasma ... More
High-resolution radio imaging of the gamma-ray blazar candidate J1331+2932Feb 20 2019Active galactic nuclei are the most luminous persistent (non-transient, even if often variable) objects in the Universe. They are bright in the entire electromagnetic spectrum. Blazars are a special class where the jets point nearly to our line of sight. ... More
The rise and fall of a binary AGN candidate: the story of PSO J334.2028+1.4075Feb 20 2019Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret the variability as the orbital period of a binary supermassive black hole (SMBH) residing in a single circumbinary ... More
The highly peculiar emission lines detected in spectra of extragalactic objects may be generated by ultra-rapid quasi-periodic oscillationsFeb 19 2019Extremely peculiar emission lines have been found in the spectra of some active galactic nuclei and quasars. Their origin is totally unknown. We investigate the hypothesis that they are generated from ultra-rapid quasi-periodic oscillations that may occur ... More
Gamma rays from jets interacting with BLR clouds in blazarsFeb 19 2019The innermost parts of powerful jets in active galactic nuclei are surrounded by dense, high-velocity clouds from the broad-line region, which may penetrate into the jet and lead to the formation of a strong shock. Such jet-cloud interactions are expected ... More
High-Precision X-ray Timing of Three Millisecond Pulsars with NICER: Stability Estimates and Comparison with RadioFeb 19 2019The Neutron Star Interior Composition Explorer (NICER) is an X-ray astrophysics payload on the International Space Station. It enables unprecedented high-precision timing of millisecond pulsars without the pulse broadening and delays due to dispersion ... More
On Constraining the Growth History of Massive Black Holes via Their Distribution on the Spin-Mass PlaneFeb 19 2019The spin distribution of massive black holes (MBHs) contains rich information on the MBH growth history. In this paper, we investigate the spin evolution of MBHs by assuming that each MBH experiences two-phase accretion, with an initial phase of coherent-accretion ... More
Constraining the era of helium reionization using fast radio burstsFeb 19 2019The discovery of fast radio bursts (FRBs) about a decade ago opened up new possibilities for probing the ionization history of the Intergalactic Medium (IGM). In this paper we study the use of FRBs for tracing the epoch of HeII reionization, using simulations ... More
Background for a gamma-ray satellite on a low-Earth orbitFeb 19 2019The different background components in a low-Earth orbit have been modeled in the 10 keV to 100 GeV energy range. The model is based on data from previous instruments and it considers both primary and secondary particles, charged particles, neutrons and ... More
Absence of Landau-Peierls Instability in the Magnetic Dual Chiral Density Wave Phase of Dense QCDFeb 18 2019We investigate the stability of the Magnetic Dual Chiral Density Wave (MDCDW) phase of cold and dense QCD against collective low-energy fluctuations of the order parameter. The appearance of additional structures in the system free-energy due to the explicit ... More
Charged spherically symmetric black holes in $f(R)$ gravityFeb 18 2019A new class of analytic charged spherically symmetric black hole solutions, which behave asymptotically as flat or (A)dS spacetimes, is derived for specific classes of $f(R)$ gravity, i.e., $f(R)=R-2\alpha\sqrt{R}$ and $f(R)=R-2\alpha\sqrt{R-8\Lambda}$, ... More
ECO-like behavior in black hole analoguesFeb 18 2019Classical phenomenological aspects of acoustic perturbations on a draining bathtub geometry where a surface with reflectivity $\mathcal{R}$ is set at a small distance from the would-be acoustic horizon, which is excised, are addressed. A low-frequency ... More
Resolving the decades-long transient FIRST J141918.9+394036: an orphan long gamma-ray burst or a young magnetar nebula?Feb 18 2019Ofek (2017) identified FIRST J141918.9+394036 (hereafter FIRST J1419+3940) as a radio source sharing similar properties and host galaxy type to the compact, persistent radio source associated with the first known repeating fast radio burst, FRB 121102. ... More
Synthetic Spectra of Pair-Instability Supernovae in 3DFeb 18 2019Pair-Instability Supernovae (PISNe) may signal the deaths of extremely massive stars in the local Universe or massive primordial stars after the end of the Cosmic Dark Ages. Hydrodynamic simulations of these explosions, performed in 1D, 2D, and 3D geometry, ... More
The $ν$-process with fully time-dependent supernova neutrino emission spectraFeb 18 2019The neutrino process that occurs in the outer stellar shells during a supernova explosion and involves neutrino-nucleus reactions produces a range of rare, stable and radioactive isotopes. We improve previous $\nu$-process studies by using, for the first ... More
An Arena for Multi-Messenger Astrophysics: Inspiral and Tidal Disruption of White Dwarfs by Massive Black HolesFeb 18 2019The tidal disruption of stars by (super-)massive black holes in galactic nuclei has been discussed in theoretical terms for about 30 years but only in the past decade have we been able to detect such events in substantial numbers. Thus, we are now starting ... More
Probing the space time around a black hole with X-ray variabilityFeb 18 2019In the past decades, the phenomenology of fast time variations of high-energy flux from black-hole binaries has increased, thanks to the availability of more and more sophisticated space observatories, and a complex picture has emerged. Recently, models ... More
Incompressible analytical models for spinning-down pulsarsFeb 17 2019We study a class of Newtonian models for the deformations of non-magnetized neutron stars during their spin-down. The models have all an analytical solution, and thus allow to understand easily the dependence of the strain on the star's main physical ... More
The Efficiency of Coherent Radiation from Relativistic ShocksFeb 17 2019We discuss a mechanism for intense electromagnetic wave emission at an astrophysical relativistic shock in a magnetized collisionless plasma. At the magnetized shock, the particle reflection by a compressed magnetic field of the shock produces a ring-like ... More
Hydrodynamical simulations and similarity relations for eruptive mass loss from massive starsFeb 17 2019Motivated by the eruptive mass loss inferred from Luminous Blue Variable (LBV) stars, we present 1D hydrodynamical simulations of the response from sudden energy injection into the interior of a very massive ($100 \, M_\odot$) star. For a fiducial case ... More
Probing the Final-stage Progenitor Evolution for Type IIP Supernova 2017eaw in NGC 6946Feb 17 2019We presented a detailed analysis of progenitor properties of type IIP supernova 2017eaw in NGC 6946, based on the pre-explosion images and early-time observations obtained immediately after the explosion. An unusually red star, with M$_{F814W}$ = $-$6.9 ... More
Understanding the cosmic ray positron fluxFeb 16 2019Recent precision measurements of the flux of cosmic ray positrons by the Alpha Magnetic Spectrometer show that the spectrum has a marked softening feature for energies close to one TeV. A possible interpretation of this result is that the observed feature ... More
The key role of BeppoSAX in the GRB historyFeb 16 2019Twenty years have already been elapsed from the BeppoSAX discovery of the first afterglow of a Gamma Ray Burst (GRB) on February 28, 1997. Thanks to this discovery, it was possible to unveil the 30 year mystery about GRB origin: GRBs are huge explosions ... More
Spectral and morphological study of the gamma radiation of the middle-aged supernova remnant HB 21Feb 16 2019We investigate the nature of the accelerated particles responsible for the production of the gamma-ray emission observed from the middle-aged supernova remnant (SNR) HB 21. The analysis of more than nine years of Fermi LAT data leads to the observation ... More
Wind-accreting Symbiotic X-ray BinariesFeb 16 2019We present a new model of the population of symbiotic X-ray binaries (SyXBs) that takes into account non-stationary character of quasi-spherical sub-sonic accretion of the red giant's stellar wind onto slowly rotating neutron stars. Updates of the earlier ... More
A new fast radio burst in the datasets containing the Lorimer burstFeb 15 2019We report the discovery of a new fast radio burst (FRB), FRB~010312, in archival data from a 1.4\,GHz survey of the Magellanic Clouds using the multibeam receiver on the Parkes 64\,m-diameter radio telescope. These data sets include the Lorimer burst ... More
$^{60}$Fe in core-collapse supernovae and prospects for X-ray and $γ$-ray detection in supernova remnantsFeb 15 2019We investigate $^{60}$Fe in massive stars and core-collapse supernovae focussing on uncertainties that influence its production in 15, 20 and 25 $M_\odot$ stars at solar metallicity. We find that the $^{60}$Fe yield is a monotonic increasing function ... More
Millisecond Pulsars and Black Holes in Globular ClustersFeb 15 2019Over a hundred millisecond radio pulsars (MSPs) have been observed in globular clusters (GCs), motivating theoretical studies of the formation and evolution of these sources through stellar evolution coupled to stellar dynamics. Here we study MSPs in ... More
Detecting dark photon dark matter with Gaia-like astrometry observationsFeb 15 2019A class of dark photon dark matter models with ultralight masses would lead to oscillation of a test body through a coupling with baryons or $B-L$ charge. This periodical oscillation of an observer results in swing of a star's apparent position due to ... More
The Origin of Radio Emission from Radio-Quiet AGNFeb 15 2019The central nuclei of galaxies, where super-massive black holes (SMBHs) are thought to reside, can experience phases of activity when they become Active Galactic Nuclei (AGN). An AGN can eject winds, jets, and produce radiation across the entire electromagnetic ... More
Nonthermal emission in the lobes of Fornax AFeb 15 2019Current measurements of the spectral energy distribution in radio, X-and-gamma-ray provide a sufficiently wide basis for determining basic properties of energetic electrons and protons in the extended lobes of the radio galaxy Fornax A. Of particular ... More
Neutrinos below 100 TeV from the southern sky employing refined veto techniques to IceCube dataFeb 15 2019Many Galactic sources of gamma rays, such as supernova remnants, are expected to produce neutrinos with a typical energy cutoff well below 100 TeV. For the IceCube Neutrino Observatory located at the South Pole, the southern sky, containing the inner ... More
Wormhole as a possible accelerator of high-energy cosmic-ray particlesFeb 15 2019We present the simplest topological classification of wormholes and demonstrate that in open Friedmann models the genus $n\geq 1$ wormholes are stable and do not require the presence of exotic forms of matter, or any modification of general relativity. ... More
Photoionization Emission Models for the Cyg X-3 X-ray SpectrumFeb 14 2019Feb 21 2019We present model fits to the X-ray line spectrum of the well known High Mass X-ray binary Cyg X-3. The primary observational dataset is a spectrum taken with the $Chandra$ X-ray Observatory High Energy Transmission Grating (HETG) in 2006, though we compare ... More
Photoionization Emission Models for the Cyg X-3 X-ray SpectrumFeb 14 2019We present model fits to the X-ray line spectrum of the well known High Mass X-ray binary Cyg X-3. The primary observational dataset is a spectrum taken with the $Chandra$ X-ray Observatory High Energy Transmission Grating (HETG) in 2006, though we compare ... More
The High Time Resolution Universe Pulsar Survey -- XV: completion of the intermediate latitude survey with the discovery and timing of 25 further pulsarsFeb 14 2019We report on the latest six pulsars discovered through our standard pipeline in the intermediate-latitude region (|b| < 15 deg) of the Parkes High Time Resolution Universe Survey (HTRU). We also present timing solutions for the new discoveries and for ... More
First Results from the TNG50 Simulation: Galactic outflows driven by supernovae and black hole feedbackFeb 14 2019We present the new TNG50 cosmological, magnetohydrodynamical simulation -- the third and final volume of the IllustrisTNG project. This simulation occupies a unique combination of large volume and high resolution, with a 50 Mpc box sampled by 2160^3 gas ... More
Bayesian modeling of the nuclear equation of state for neutron star tidal deformabilities and GW170817Feb 14 2019We present predictions for neutron star tidal deformabilities obtained from a Bayesian analysis of the nuclear equation of state. The Bayesian posterior probability distribution is constructed from priors obtained from microscopic many-body theory based ... More
A comprehensive statistical study on gamma-ray burstsFeb 14 2019In order to obtain an overview of the gamma-ray bursts (GRBs), we need a full sample. In this paper, we collected 6289 GRBs (from GRB 910421 to GRB 160509A) from the literature, including prompt emission, afterglow and host galaxy properties. We hope ... More
Cosmological evolution of quasar radio emission in the view of multifractalityFeb 14 2019Variations in scaling behavior in the flux and emissions of distant astronomical sources with respect to their cosmic time are important l phenomena that can provide valuable information about the dynamics within the sources and their cosmological evolution ... More
No-go theorem for static boson starsFeb 14 2019It is proved that self-gravitating static scalar fields whose self-interaction potential $V(\psi^2)$ is a monotonically increasing function of its argument cannot form spherically symmetric asymptotically flat bound matter configurations. Our compact ... More
An enigmatic hump around 30 keV in Suzaku spectra of Aquila X-1 in the Hard StateFeb 14 2019The typical accreting neutron star, Aquila X-1, was observed with Suzaku seven times in the decay phase of an outburst in 2007 September-October. Among them, the second to the fourth observations were performed 10 to 22 days after the outburst peak, when ... More
Investigation of the asteroid-neutron star collision model for the repeating fast radio burstsFeb 14 2019The origin of fast radio bursts (FRBs) is still a mystery. One model proposed to interpret the only known repeating object, FRB 121102, is that the radio emission is generated from asteroids colliding with a highly magnetized neutron star (NS). With N-body ... More
GROJ1750-27: a neutron star far behind the Galactic Center switching into the propeller regimeFeb 13 2019We report on analysis of properties of the X-ray binary pulsar GROJ1750-27 based on X-ray (Chandra, Swift, and Fermi/GBM), and near-infrared (VVV and UKIDSS surveys) observations. An accurate position of the source is determined for the first time and ... More
Discovery of Strongly-lensed Gravitational Waves - Implications for the LSST Observing StrategyFeb 13 2019LSST's wide-field of view and sensitivity will revolutionize studies of the transient sky by finding extraordinary numbers of new transients every night. The recent discovery of a kilonova counterpart to LIGO/Virgo's first detection of gravitational waves ... More
The source number counts at high energies: SWIFT vs. NuSTARFeb 13 2019The hard X-ray sky at energies above 10 keV, has been extensively explored by the Swift and the NuSTAR missions in the 14-195 keV and the 3-24 keV bands respectively. The major population of the hard X-ray detected sources are AGN. We compare the number ... More
Constraining the neutron star equation of state using multi-band independent measurements of radii and tidal deformabilitiesFeb 13 2019Using a Bayesian approach, we combine measurements of neutron star macroscopic observables obtained by astrophysical and gravitational observations, to derive joint constraints on the equation of state (EoS) of matter at supranuclear density. In our analysis ... More
X-Ray Spectral Variability of Ultraluminous X-Ray Sources in Extragalactic Globular ClustersFeb 13 2019A number of ultraluminous X-ray sources (ULXs) are physically associated with extragalactic globular clusters (GCs). We undertake a systematic X-ray analysis of eight of the brightest of these sources. We fit the spectra of the GC ULXs to single power ... More
CHIANTI - an atomic database for emission lines - Paper XV: Version 9, improvements for the X-ray satellite linesFeb 13 2019CHIANTI contains a large quantity of atomic data for the analysis of astrophysical spectra. Programs are available in IDL and Python to perform calculation of the expected emergent spectrum from these sources. The database includes atomic energy levels, ... More
Gamma rays from red giant wind bubbles entering the jets of elliptical host blazarsFeb 13 2019Blazars in elliptical hosts have a population of red giants surrounding their jet. These stars can carry large wind-blown bubbles into the jets, leading to gamma-ray emission through bubble-jet interactions. We study the interaction dynamics and the gamma-ray ... More
Limit on the population of repeating fast radio bursts from the ASKAP/CRAFT lat50 surveyFeb 13 2019A method is presented to limit the volumetric density of repeating fast radio bursts based on the number (or lack) of repeating bursts identified in a survey. The method incorporates the instantaneous sensitivity of the instrument, its beam pattern, and ... More
Two-mediator dark matter models and cosmic electron excessFeb 13 2019The cosmic electron energy spectrum recently observed by the DAMPE experiment exhibits two interesting features, including a break around 0.9 TeV and a sharp resonance near 1.4 TeV. In this analysis, we propose a dark matter explanation to both exotic ... More
Delayed Outburst of H 1743--322 in 2003 and relation with its other outburstsFeb 13 2019The Galactic transient black hole candidate H 1743--322 exhibited a long duration outburst in 2003 after more than two and a half decades of inactivity. The 2003 event was extensively studied in multi-wavelength bands by many groups. The striking feature ... More
Detailed study of detection method for ultra-low-frequency gravitational waves with pulsar spin-down rate statisticsFeb 13 2019A new detection method for gravitational waves (GWs) with ultra-low frequencies ($f_{\rm GW} \lesssim 10^{-10}~{\rm Hz}$), which is much lower than the range of pulsar timing arrays (PTAs), was proposed in Yonemaru et al. (2016). This method utilizes ... More
Cavities, shocks and a cold front around 3C 320Feb 13 2019We present results obtained from the analysis of a total of 110 ks Chandra observations of 3C 320 FR II radio galaxy, located at the centre of a cluster of galaxies at a redshift $z=0.342$. A pair of X-ray cavities have been detected at an average distance ... More
Minimalist shear-driven large scale dynamoFeb 13 2019We show that non-axisymmetric, non-helical perturbations in an unstratified shear flow produce a shear-plane averaged electromotive force (EMF) rigorously proportional to a spatially dependent kinetic helicity. This new "shear-driven $\alpha$-effect" ... More
Bell-Instability-Mediated Spectral Modulation of Hadronic Gamma Rays from a Supernova Remnant Interacting with a Molecular CloudFeb 13 2019Supernova remnants (SNRs) are believed to be the site of galactic cosmic-ray acceleration. However, the details of the cosmic-ray acceleration are still not well understood. Gamma ray observation is a promising method to study cosmic-ray acceleration ... More
Wideband polarized radio emission from the newly revived radio magnetar XTE J1810$-$197Feb 13 2019The anomalous X-ray pulsar XTE J1810$-$197 was the first magnetar found to emit pulsed radio emission. After spending almost a decade in a quiescent, radio-silent state, the magnetar was reported to have undergone a radio outburst in early 2018 December. ... More
A model of high-energy emission from jets of microquasars of Population IIIFeb 12 2019Current research indicates that the radiation of the first stars alone would not have been suficient to ionize the intergalactic medium on long distances because of the high columnar density of the clouds in which they formed. It becomes necessary, then, ... More
Super-Eddington accretion discs with advection and outflows around magnetized neutron starsFeb 12 2019We present a model for a super-Eddington accretion disc around a magnetized neutron star taking into account advection of heat and the mass loss by the wind. The model is semi-analytical and predicts radial profiles of all basic physical characteristics ... More
Gravitational Waves from Compact Dark Objects in Neutron StarsFeb 12 2019Dark matter could be composed of compact dark objects (CDOs). We find that the oscillation of CDOs inside neutron stars can be a detectable source of gravitational waves (GWs). The GW strain amplitude depends on the mass of the CDO, and its frequency ... More
A Dark Matter Interpretation of the ANITA Anomalous EventsFeb 12 2019The ANITA collaboration recently reported the detection of two anomalous upward-propagating extensive air showers exiting the Earth with relatively large emergence angles and energies in the range $\mathcal{O}(0.5\!-\!1)~\mathrm{EeV}$. We interpret these ... More
Can supernova kicks trigger EMRIs in the Galactic Centre?Feb 12 2019One of the most promising gravitational wave (GW) sources detectable by the forthcoming LISA observatory are the so-called extreme-mass ratio inspirals (EMRIs), i.e. GW-driven inspirals of stellar-mass compact objects onto supermassive black holes (SMBHs). ... More
Inferring Neutron Star Properties from GW170817 with Universal RelationsFeb 12 2019Because all neutron stars share a common equation of state, tidal deformability constraints from the compact binary coalescence GW170817 have implications for the properties of neutron stars in other systems. Using equation-of-state insensitive relations ... More
Are quantum corrections on horizon scale physically motivated?Feb 12 2019The aim of this note is to give an overview to non-specialists of recent arguments from fundamental physics in favor and disfavor of quantum corrections to black hole horizons. I will mainly discuss the black hole information paradox, its possible resolutions ... More
Science with TianQin: Preliminary Results on Massive Black Hole BinariesFeb 12 2019We investigate the prospects of detecting gravitational waves from coalescing massive black hole binaries in the Universe with the TianQin observatory, a space-based gravitational wave interferometer proposed to be launched in the 2030s. To frame the ... More
The jet of S5 0716+71 at $μ$as scales with RadioAstronFeb 12 2019Ground-space interferometer RadioAstron provides unique opportunity to probe detail structure of the distant active galactic nuclei at $\mu$as scales. Here we report on RadioAstron observations of the BL Lac object S5 0716$+$71, performed in a framework ... More
A Critical Assessment of Turbulence Models for 1D Core-Collapse Supernova SimulationsFeb 12 2019It has recently been proposed that global or local turbulence models can be used to simulate core-collapse supernova explosions in spherical symmetry (1D) more consistently than with traditional approaches for parameterised 1D models. However, a closer ... More
Rapid "Turn-on" of type 1 AGN in a quiescent early type galaxy SDSS1115+0544Feb 11 2019We present a detailed study of a transient in the center of SDSS1115+0544 based on the extensive UV, optical, mid-IR light curves (LC) and spectra over 1200 days. The host galaxy is a quiescent early type galaxy at $z$ = 0.0899 with a blackhole mass of ... More
Black hole masses of tidal disruption event host galaxies IIFeb 11 2019We present new medium resolution, optical long-slit spectra of a sample of 6 UV/optical and 15 X-ray selected tidal disruption event candidate host galaxies. We measure emission line ratios from the optical spectra, finding that the large majority of ... More
On the magnetic field in M51 ULX-8Feb 11 2019The reported discovery of a cyclotron resonance scattering feature (CRSF) in the spectrum of M51 ULX-8 may provide an important clue as to the nature of the magnetic field in those ultraluminous X-ray sources hosting neutron stars. In this paper we present ... More
Constraints on the ultra-high energy cosmic neutrino flux from the fourth flight of ANITAFeb 11 2019The ANtarctic Impulsive Transient Antenna (ANITA) NASA long-duration balloon payload completed its fourth flight in December 2016, after 28 days of flight time. ANITA is sensitive to impulsive broadband radio emission from interactions of ultra-high-energy ... More
On the possibilities of high-energy neutrino production in the jets of microquasar SS433 in light of new observational dataFeb 11 2019Microquasar SS433 is composed by a supergiant star that feeds mass through a supercritical accretion disk to a $\sim 10 \ M_\odot$ black hole. The latter launches two oppositely directed jets that precess with a period of $162$ days. The system has been ... More
Circular polarisation in compact radio sources: Constraints on particle acceleration and electron-positron pairsFeb 11 2019It is shown that the frequency distribution of the degree of circular polarisation for a homogeneous source is sensitive to the properties of the synchrotron emitting plasma. Most of the circular polarisation comes from the region around the turn-over ... More
A New Method to Measure Star Formation Rates in Active Galaxies Using Mid-infrared Neon Emission LinesFeb 11 2019The star formation rate (SFR) is one of the most fundamental parameters of galaxies, but nearly all of the standard SFR diagnostics are difficult to measure in active galaxies because of contamination from the active galactic nucleus (AGN). Being less ... More
Searching for cool and cooling X-ray emitting gas in 45 galaxy clusters and groupsFeb 11 2019We present a spectral analysis of cool and cooling gas in 45 cool-core clusters and groups of galaxies obtained from Reflection Grating Spectrometer (RGS) XMM-$Newton$ observations. The high-resolution spectra show FeXVII emission in many clusters, which ... More
First detection of frequency-dependent, time-variable Dispersion MeasuresFeb 11 2019Context. High-precision pulsar-timing experiments are affected by temporal variations of the Dispersion Measure (DM), which are related to spatial variations in the interstellar electron content. Correcting for DM variations relies on the cold-plasma ... More
First detection of frequency-dependent, time-variable dispersion measuresFeb 11 2019Feb 15 2019Context. High-precision pulsar-timing experiments are affected by temporal variations of the Dispersion Measure (DM), which are related to spatial variations in the interstellar electron content. Correcting for DM variations relies on the cold-plasma ... More
The Palomar Transient Factory Sky2Night programmeFeb 11 2019We present results of the Sky2Night project: a systematic, unbiased search for fast optical transients with the Palomar Transient Factory. We have observed 407 deg$^2$ in $R$-band for 8 nights at a cadence of 2 hours. During the entire duration of the ... More
Accretion flows with comparable radiation and gas pressuresFeb 11 2019By taking into account photon absorption, we investigate the vertical structure of accretion flows with comparable radiation and gas pressures. We consider two separate energy equations for matter and radiation in the diffusion limit. In order to solve ... More
Stellar energetic particles in the magnetically turbulent habitable zones of TRAPPIST-1-like planetary systemsFeb 11 2019Planets in close proximity to their parent star, such as those in the habitable zones around M dwarfs, could be subject to particularly high doses of particle radiation. We have carried out test-particle simulations of ~GeV protons to investigate the ... More
The Sagnac effect on a scale-dependent rotating BTZ black hole backgroundFeb 11 2019In this paper we investigate the Sagnac effect by calculating the difference in travel time and phase shift observed for photon beams counter--propagating in a rotating interferometer on a BTZ black hole solution in the context of scale-dependent gravity, ... More
Neutron-mirror neutron oscillations in starsFeb 10 2019Based on a newly proposed model of neutron-mirror neutron ($n-n'$) oscillations, evolution and nucleosynthesis in single stars under a new theory is presented. The new theory with the new $n-n'$ model can demonstrate the evolution in a much more convincing ... More
Neutron-mirror neutron oscillations in starsFeb 10 2019Feb 12 2019Based on a newly proposed model of neutron-mirror neutron ($n-n'$) oscillations, evolution and nucleosynthesis in single stars under a new theory is presented. The new theory with the new $n-n'$ model can demonstrate the evolution in a much more convincing ... More
Deep learning detection of transientsFeb 10 2019The next generation of observatories will facilitate the discovery of new types of astrophysical transients. The detection of such phenomena, whose characteristics are presently poorly constrained, will hinge on the ability to perform blind searches. ... More
Cosmic Anisotropy and Fast Radio BurstsFeb 10 2019In the recent years, the field of Fast Radio Bursts (FRBs) is thriving and growing rapidly. It is of interest to study cosmology by using FRBs with known redshifts. In the present work, we try to test the possible cosmic anisotropy with the simulated ... More
Steep X-ray reflection emissivity profiles in AGN as the result of radially-structured disc ionisationFeb 09 2019X-ray observations suggest high compactness of coronae in active galactic nuclei as well as in X-ray binaries. The compactness of the source implies a strong radial dependence in the illumination of the accretion disc. This will, for any reasonable radial ... More
A possible feedback mechanism of outflows from a black hole hyperaccretion disk in the center of jet-driven iPTF14hlsFeb 09 2019iPTF14hls is an unusually bright, long-lived II-P supernova (SN), whose light curve has at least five peaks. We propose that the outflows from the black hole hyperaccretion systems in the center of the collapsars should continuously inject into the envelope. ... More
Full particle-in-cell simulation of the interaction between two plasmas for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasersFeb 09 2019A preliminary numerical experiment is conducted for laboratory experiments on the generation of magnetized collisionless shocks with high-power lasers by using one-dimensional particle-in-cell simulation. The present study deals with the interaction between ... More
Foliation-based approach to quantum gravity and applications to astrophysicsFeb 09 2019The recently proposed Holography-inspired approach to quantum gravity is reviewed and expanded. The approach is based on the foliation of the background spacetime and reduction of the offshell states to the physical states. Careful attention is paid to ... More
Sub-Eddington super-massive black hole activity in Fornax early type galaxiesFeb 08 2019We characterize the incidence and intensity of low-level super-massive black hole activity within the Fornax cluster, through X-ray observations of the nuclei of 29 quiescent early-type galaxies. Using the \textit{Chandra X-ray Telescope}, we target 17 ... More
The mass distribution of Galactic double neutron starsFeb 08 2019The conventional wisdom dating back to 2012 is that the mass distribution of Galactic double neutron stars is well-fit by a Gaussian distribution with a mean of $1.33 M_\odot$ and a width of $0.09 M_\odot$. With the recent discovery of new Galactic double ... More
The rate of stellar mass black hole scattering in galactic nucleiFeb 08 2019We consider a black hole (BH) density cusp in a nuclear star cluster (NSC) hosting a supermassive back hole (SMBH) at its center. Assuming the stars and BHs inside the SMBH sphere of influence are mass-segregated, we calculate the number of BHs that sink ... More
Spin dynamics of a millisecond pulsar orbiting closely around a massive black holeFeb 08 2019We investigate the spin dynamics of a millisecond pulsar (MSP) in a tightly bounded orbit around a massive black hole. These binaries are progenitors of the extreme-mass-ratio-inspirals (EMRIs) and intermediate-mass-ratio-inspirals (IMRIs) gravitational ... More
Evidence for Radiation Pressure Compression in the X-ray Narrow Line Region of Seyfert galaxiesFeb 08 2019The observed spatial and kinematic overlap between soft X-ray emission and the Narrow Line Region (NLR) in obscured Active Galactic Nuclei (AGN) yields compelling evidence that relatively low-density gas co-exists with higher density gas on scales as ... More