Latest in astro-ph

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Massive star feedback in clusters: variation of the FUV interstellar radiation field in time and spaceJun 13 2019We investigate radiative feedback from a 34 M$_\odot$ star in a $10^4$ M$_\odot$ turbulent cloud using three-dimensional radiation-hydrodynamics (RHD) models. We use Monte Carlo radiative transfer to accurately compute photoionization equilibrium and ... More
Effects of a Binary Companion Star on Habitability of Tidally Locked Planets around an M-type Host StarJun 13 2019Planets in the "Habitable Zones" around M-type stars are important targets for characterization in future observations. Due to tidal-locking in synchronous spin-orbit rotations, the planets tend to have a hot dayside and a cold nightside. On the cold ... More
Self-Organized Criticality in Solar and Stellar Flares: Are Extreme Events Scale-Free ?Jun 13 2019We search for outliers in extreme events of statistical size distributions of astrophysical data sets, motivated by the {\sl Dragon-King hypothesis} of Sornette (2009), which suggests that the most extreme events in a statistical distribution may belong ... More
Global Energetics of Solar Flares: VIII. The Low-Energy CutoffJun 13 2019One of the key problems in solar flare physics is the determination of the low-energy cut-off; the value that determines the energy of nonthermal electrons and hence flare energetics. We discuss different approaches to determine the low-energy cut-off ... More
Type IIn supernova light-curve properties measured from an untargeted survey sampleJun 13 2019We present a sample of supernovae Type IIn (SNe IIn) from the untargeted, magnitude-limited surveys of the Palomar Transient Factory (PTF) and its successor, iPTF. SNe IIn found and followed by the PTF/iPTF were used to select a sample of 42 events with ... More
Global Energetics of Solar Flares: VII. Aerodynamic Drag in Coronal Mass EjectionsJun 13 2019The free energy that is dissipated in a magnetic reconnection process of a solar flare, generally accompanied by a coronal mass ejection (CME), has been considered as the ultimate energy source of the global energy budget of solar flares in previous statistical ... More
Paleo-Detectors for Galactic Supernova NeutrinosJun 13 2019Paleo-detectors are a proposed experimental technique in which one would search for traces of recoiling nuclei in ancient minerals. Natural minerals on Earth are as old as $\mathcal{O}(1)$ Gyr and, in many minerals, the damage tracks left by recoiling ... More
A Tip for Landscape Riders: Multi-Field Inflation Can Fulfill the Swampland Distance ConjectureJun 13 2019We study how both the swampland distance conjecture and the Lyth bound affect the parameter space of multi-field models of inflation. A generic feature of multi-field inflation is that the geodesic distance $\left[\Delta\phi\right]_\text{G}$ separating ... More
Theoretical Study of Interstellar Heterocyclic MoleculesJun 13 2019Because of their importance in biological systems, in our understanding of the solar system and in other applications, seven heterocycles; furan, imidazole, pyridine, pyrimidine, pyrrole, quinoline and isoquinoline have been astronomically searched for ... More
Warm Absorber Diagnostics of AGN DynamicsJun 13 2019Warm absorbers and related phenomena are one of the observable manifestations of outflows or winds from active galactic nuclei (AGN). Warm absorbers are common in low luminosity AGN, they have been extensively studied observationally, and are well described ... More
Cosmic snow clouds: self-gravitating gas spheres manifesting hydrogen condensationJun 13 2019We present hydrostatic equilibrium models of spherical, self-gravitating clouds of helium and molecular hydrogen, focusing on the cold, high-density regime where solid- or liquid-hydrogen can form. The resulting structures have masses from 0.1 Msun down ... More
Cosmological perfect fluids in Gauss-Bonnet gravityJun 13 2019In an $n$-dimensional Friedmann-Robertson-Walker metric, it is rigorously shown that any smooth theory of gravity $f(R,{\cal G})$, where $R$ is the curvature scalar and $\cal G$ is the Gauss-Bonnet topological invariant, can be associated to a perfect-fluid ... More
Resolved neutral carbon emission in nearby galaxies: [CI] Lines as Total Molecular Gas TracersJun 13 2019We present maps of atomic carbon [CI](1-0) and [CI](2-1) at a linear resolution ~1kpc scale for a sample of one HII, six LINER, three Seyfert and five starburst galaxies observed with Herschel. We compare spatial distributions of two [CI] lines with that ... More
Determining mass limits around HD163296 through SPHERE direct imaging dataJun 13 2019HD163296 is a Herbig Ae/Be star known to host a protoplanetary disk with a ringed structure. To explain the disk features, previous works proposed the presence of planets embedded into the disk. We have observed HD163296 with the near-infrared (NIR) branch ... More
Thin glass shells for active optics for future space telescopesJun 13 2019We present a method for the manufacturing of thin shells of glass, which appears promising for the development of active optics for future space telescopes. The method exploits the synergy of different mature technologies, while leveraging the commercial ... More
On the interpretation of Parker Solar Probe Turbulent SignalsJun 13 2019In this letter we propose a practical methodology to interpret future Parker Solar Probe (PSP) turbulent time signals even when Taylor's hypothesis is not valid. By extending Kraichnan's sweeping model used in hydrodynamics we derive the Eulerian spacetime ... More
Ultimate Merging at z~0.1Jun 13 2019We present a study of 58 double-peaked emission line galaxies for which one of the components is suppressed in [OIII]5008 or significantly weaker than the other one. Accordingly, the two components are classified differently in the BPT diagram. We show ... More
Evolutionary models for ultracool dwarfsJun 13 2019Ultracool dwarfs have emerged as key targets for searches of transiting exoplanets. Precise estimates of the host parameters (including mass, age, and radius) are fundamental to constrain the physical properties of orbiting exoplanets. We have extended ... More
UBVRI-KC Photometry of NGC~2323 and NGC~2539 Open ClustersJun 13 2019The open clusters NGC 2323 and NGC 2539 have been analysed using CCD UBV(RI)KC photometric data, observed at the San Pedro Martir Observatory. Cluster memberships have been determined with the proper motion and parallax measures from the GaiaDR2 astrometric ... More
A comprehensive and uniform sample of broad-line active galactic nuclei from the SDSS DR7Jun 13 2019A new, complete sample of 14,584 broad-line AGNs at $z<0.35$ is presented, which are uncovered homogeneously from the complete database of galaxies and quasars observed spectroscopically in the Sloan Digital Sky Survey Seventh Data Release. The stellar ... More
Activity and rotation of the X-ray emitting Kepler starsJun 13 2019The relation between magnetic activity and rotation in late-type stars provides fundamental information on stellar dynamos and angular momentum evolution. Rotation/activity studies found in the literature suffer from inhomogeneity in the measure of activity ... More
Models for Weak Wind and Momentum Problems in the Winds of Hot StarsJun 13 2019We pesent models for the velocity structure in the supersonic part of hot star winds in order to estimate the effects of clumping in density and velocity. XSTAR (Kallman,2018) was used to calculate radiation pressure in spectral lines (force multiplier ... More
Local semi-analytic models of magnetic flux transport in protoplanetary discsJun 13 2019The evolution of a large-scale poloidal magnetic field in an accretion disc is an important problem because it determines the launching of winds and the feasibility of the magnetorotational instability to generate turbulence or channel flows. Recent studies, ... More
The specific angular momentum radial profile in dense cores: improved initial conditions for disk formationJun 13 2019Determination of the specific angular momentum radial profile, $j(r)$, in the early stages of star formation is crucial to constrain star and circumstellar disk formation theories. The specific angular momentum is directly related to the largest Keplerian ... More
Developing a mass-production model of large-area Si(Li) detectors with high operating temperaturesJun 13 2019This study presents a fabrication process for lithium-drifted silicon (Si(Li)) detectors that, compared to previous methods, allows for mass production at a higher yield, while providing a large sensitive area and low leakage currents at relatively high ... More
Evidence from stellar rotation for early disc dispersal owing to close companionsJun 13 2019Young low-mass stars of equal-mass exhibit a distribution of rotation periods. At the very early phases of stellar evolution, this distribution is set by the star-disc locking mechanism. The primordial disc lifetime and, consequently, the duration of ... More
HL Tau disk in HCO+ (3-2) and (1-0) with ALMA: gas density, temperature, gap, and one-arm spiralJun 13 2019We present our observational results of the 1.1 mm continuum and the HCO+ (3-2) line in HL Tau at angular resolutions of 0.1" obtained with ALMA and our data analysis of the 2.9 mm and 1.1 mm continuum and the HCO+ (3-2) and (1-0) lines of the HL Tau ... More
The HD 181433 Planetary System: Dynamics and a New Orbital SolutionJun 13 2019We present a detailed analysis of the orbital stability of the HD 181433 planetary system, finding it to exhibit strong dynamical instability across a wide range of orbital eccentricities, semi-major axes, and mutual inclinations. We also analyse the ... More
First Detection of Photons with Energy Beyond 100 TeV from an Astrophysical SourceJun 13 2019We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of muon number measured in an air shower, we successfully suppress ... More
The escape of hydrogen-rich atmosphere of exoplanet: Mass loss rates and the absorptions of stellar Lyman $α$Jun 13 2019Since the mass loss rates are the function of the mean density of the planet and the stellar irradiation, we calculated about 450 models covering planets with different densities and stellar irradiation. Our results show that the mass loss rates are dependent ... More
Nuclear Mass Measurements With Radioactive Ion BeamsJun 13 2019Nuclear masses are the most fundamental of all nuclear properties, yet they can provide a wealth of knowledge, including information on astrophysical sites, constraints on existing theory, and fundamental symmetries. In nearly all applications, it is ... More
Spatially Resolved Water Emission from Gravitationally Lensed Dusty Star Forming Galaxies at z $\sim$ 3Jun 13 2019Water ($\rm H_{2}O$), one of the most ubiquitous molecules in the universe, has bright millimeter-wave emission lines easily observed at high-redshift with the current generation of instruments. The low excitation transition of $\rm H_{2}O$, p$-$$\rm ... More
Do Delta Baryons Play a Role in Neutron Stars?Jun 13 2019The presence of exotic hadrons, such as hyperons and $\Delta$ isobars, in the dense nuclear matter in their cores has been shown to produce important changes in the properties of neutron stars. Within the quark-meson coupling model, we show that the many-body ... More
Eikonal quasinormal modes of black holes beyond General RelativityJun 13 2019Much of our physical intuition about black hole quasinormal modes in General Relativity comes from the eikonal/geometric optics approximation. According to the well-established eikonal model, the fundamental quasinormal mode represents wavepackets orbiting ... More
ALMA observations of molecular gas in the host galaxy of AT2018cowJun 13 2019We investigate the molecular gas in, and star-formation properties of, the host galaxy (CGCG 137-068) of a mysterious transient, AT2018cow, at kpc and larger scales, using archival band-3 data from the Atacama Large Millimeter/submillimeter Array (ALMA). ... More
Io's Volcanic Activity from Time Domain Adaptive Optics Observations: 2013-2018Jun 12 2019We present measurements of the near-infrared brightness of Io's hot spots derived from 2-5 micron imaging with adaptive optics on the Keck and Gemini N telescopes. The data were obtained on 271 nights between August 2013 and the end of 2018, and include ... More
A rapidly-changing jet orientation in the stellar-mass black hole V404 CygniJun 12 2019Powerful relativistic jets are one of the main ways in which accreting black holes provide kinetic feedback to their surroundings. Jets launched from or redirected by the accretion flow that powers them should be affected by the dynamics of the flow, ... More
Streaming instability: saturation in turbulent protoplanetary disksJun 12 2019The streaming instability for solid particles in protoplanetary disks is re-examined assuming the familiar alpha ($\alpha$) model for isotropic turbulence. Turbulence always reduces the growth rates of the streaming instability relative to values calculated ... More
Dynamical Friction in Interacting Relativistic SystemsJun 12 2019We study dynamical friction in interacting relativistic systems with arbitrary mean free paths and medium constituent masses. Our novel framework recovers the known limits of ideal gas and ideal fluid when the mean free path goes to infinity or zero, ... More
Statistical stellar mass corrections for high-z galaxies observed with JWST broad-band filters due to template degeneraciesJun 12 2019Stellar masses in future James Webb Space Telescope (JWST) deep blank-fields will be mainly derived fitting the spectral energy distribution with theoretical galaxy templates. We investigate the uncertainties and biases of the stellar masses derived by ... More
The energetics of starburst-driven outflows at z=1 from KMOSJun 12 2019We present an analysis of the gas outflow energetics of 529 main-sequence star-forming galaxies at z~1 using KMOS observations of the broad, underlying H-alpha and forbidden lines of [N II] and [S II]. Based on the stacked spectra for a sample with median ... More
The Orbital Lense-Thirring Precession in a Strong FieldJun 12 2019We study the exact evolution of the orbital angular momentum of a massive particle in the gravitational field of a Kerr black hole. We show analytically that, for a wide class of orbits, the angular momentum's hodograph is always close to a circle. This ... More
ALMA and HST kiloparsec-scale imaging of a quasar-galaxy merger at $z\approx 6.2$Jun 12 2019We present kpc-scale ALMA and HST imaging of the quasar PJ308-21 at $z$=$6.2342$, tracing dust, gas (via the [CII] 158 $\mu$m line) and young stars. At a resolution of $\sim0.3''$ ($\approx1.7$ kpc), the system is resolved over $>4''$ ($>$20 kpc). In ... More
Probing the shape of the mixing profile and of the thermal structure at the convective core boundary through asteroseismologyJun 12 2019Aims: We investigate from a theoretical perspective if space asteroseismology can be used to distinguish between different thermal structures and shapes of the near-core mixing profiles for different types of coherent oscillation modes in massive stars ... More
Primordial dark matter halos from fifth-forcesJun 12 2019We argue that primordial dark matter halos could be generated during radiation domination by long range attractive forces stronger than gravity. In this paper we derive the conditions under which these structures could dominate the dark matter content ... More
Signatures of stellar accretion in MaNGA early-type galaxiesJun 12 2019The late assembly of massive galaxies is thought to be dominated by stellar accretion in their outskirts (beyond 2 effective radii Re) due to dry, minor galaxy mergers. We use observations of 1010 passive early-type galaxies (ETGs) within z<0.15 from ... More
Halo MeteorsJun 12 2019The stellar halo contains some of the oldest stars in the Milky Way galaxy and in the universe. The detections of `Oumuamua, CNEOS 2014-01-08, and interstellar dust serve to calibrate the production rate of interstellar objects. We study the feasibility ... More
Long-Lived Eccentricities in Accretion DisksJun 12 2019Accretion disks can be eccentric: they support $m=1$ modes that are global and slowly precessing. But whether the modes remain trapped in the disk---and hence are long-lived---depends on conditions at the outer edge of the disk. Here we show that in disks ... More
A Correlated Search for Local Dwarf Galaxies in GALFA-HI and Pan-STARRSJun 12 2019In recent years, ultrafaint dwarf (UFD) galaxies have been found through systematic searches of large optical surveys. However, the existence of Leo T, a nearby gas-rich dwarf, suggests that there could be other nearby UFDs that are optically obscured ... More
Binary neutron star mergers: effects of spin and post-merger dynamicsJun 12 2019Spin can have significant effects on the electromagnetic transients accompanying binary neutron star mergers. The measurement of spin can provide important information about binary formation channels. In the absence of a strong neutron star spin prior, ... More
A model-independent characterisation of strong gravitational lensing by observablesJun 12 2019When light from a distant source object, like a galaxy or a supernova, travels towards us, it is deflected by massive objects that lie on its path. When the mass density of the deflecting object exceeds a certain threshold, multiple, highly distorted ... More
Linear Analysis of the Nonaxisymmetric Secular Gravitational InstabilityJun 12 2019In protoplanetary discs (PPDs) consisting of gas and dust particles, fluid instabilities induced by the drag force, including secular gravitational instability (SGI) can facilitate planet formation. Although SGI subject to the axisymmetric perturbations ... More
MASCARA-3b: A hot Jupiter transiting a bright F7 star in an aligned orbitJun 12 2019We report the discovery of MASCARA-3b, a hot Jupiter orbiting its late, bright (V=8.33) F-type host every $5.55149\pm 0.00001$ days on an almost circular orbit ($e = 0.085^{+0.023}_{-0.022}$). It is the fourth exoplanet discovered with the Multi-site ... More
On The XUV Luminosity Evolution of TRAPPIST-1Jun 12 2019We model the long-term XUV luminosity of TRAPPIST-1 to constrain the evolving high-energy radiation environment experienced by its planetary system. Using Markov Chain Monte Carlo (MCMC), we derive probabilistic constraints for TRAPPIST-1's stellar and ... More
Flying far and fast: the distribution of distant hypervelocity star candidates from Gaia DR2 dataJun 12 2019Context. Hypervelocity stars move fast enough to leave the gravitational field of their home galaxies and venture into intergalactic space. The most extreme examples known have estimated speeds in excess of 1000 km/s. These can be easily induced at the ... More
A novel analytical model of the magnetic field configuration in the Galactic CenterJun 12 2019The magnetic field in the Galactic Center (GC) is challenging to measure in detail due to its large distance in combination with a difficult foreground estimate. More precise knowledge is, however, required in particular in the context of proper modeling ... More
The Odd-Parity Galaxy BispectrumJun 12 2019The galaxy bispectrum contains a wealth of information about the early universe, gravity, as well as astrophysics such as galaxy bias. In this paper, we study the parity-odd part of the galaxy bispectrum which is hitherto unexplored. In the standard cosmological ... More
Atmospheric neutrinos and the knee of the Cosmic Ray spectrumJun 12 2019The nature of the knee in the all-particle spectrum of cosmic rays remains subject of much investigation, especially in the aftermath of recent measurements claiming the detection of a knee-like feature in the spectrum of the light component of cosmic ... More
A self-consistent weak friction model for the tidal evolution of circumbinary planetsJun 12 2019We present a self-consistent model for the tidal evolution of circumbinary planets. Based on the weak-friction model, we derive expressions of the resulting forces and torques considering complete tidal interactions between all the bodies of the system. ... More
Galactic rotation curves in Einstein's conformal gravityJun 12 2019We show quantitatively that an exact solution of Einstein's conformal gravity can explain very well the galactic rotation curves for a sample of 104 galaxies without need for dark matter or other exotic modification of gravity. The metric is an overall ... More
A model for microquasars of Population IIIJun 12 2019Current simulations indicate that the first stars were formed predominantly in binary systems. The study of the contribution of the first accreting binary systems to the reionization and heating of the intergalactic medium requires the formulation of ... More
A Very Large Array Survey of Luminous Extranuclear Star-forming Regions in Luminous Infrared Galaxies in GOALSJun 12 2019We present the first results of a high-resolution Karl G. Jansky Very Large Array (VLA) imaging survey of luminous and ultra-luminous infrared galaxies (U/LIRGs) in the Great Observatories All-Sky LIRG Survey (GOALS). From the full sample of 68 galaxies, ... More
Hydrodynamical instabilities in superfluid neutron stars with background flows between the componentsJun 12 2019The interiors of mature neutron stars are expected to be superfluid. Superfluidity of matter on the microscopic scale can have a number of large scale, potentially observable consequences, as the superfluid component of the star can now flow relative ... More
Effect of Star Rotation Rates on the Characteristics of Energetic Particle EventsJun 12 2019Recent detection of superflares on solar-type stars by Kepler mission raised a possibility that they can be associated with energetic coronal mass ejections (CMEs) and energetic particle events (SEPs). These space weather events can impact habitability ... More
On the kinematics of large-scale peculiar motionsJun 12 2019We consider the linear kinematics of large-scale peculiar motions in a perturbed Friedmann universe. In so doing, we introduce a 4-velocity "tilt", relative to the smooth Hubble expansion, and take the view point of the "real" observes that move along ... More
A phase of confined electroweak force in the early UniverseJun 12 2019We consider a modified cosmological history in which the presence of beyond-the-Standard-Model physics causes the weak gauge sector, $\mathrm{SU}(2)_L$, to confine before it is Higgsed. Under the assumption of chiral symmetry breaking, quark and lepton ... More
Parametrized black hole quasinormal ringdown. II. Coupled equations and quadratic corrections for nonrotating black holesJun 12 2019Linear perturbations of spherically symmetric spacetimes in general relativity are described by radial wave equations, with potentials that depend on the spin of the perturbing field. In previous work we studied the quasinormal mode spectrum of spacetimes ... More
Reconstruction of air-shower measurements with AERA in the presence of pulsed radio-frequency interferenceJun 12 2019The Auger Engineering Radio Array (AERA) is situated in the Argentinian Pampa Amarilla, a location far away from large human settlements. Nevertheless, a strong background of pulsed radio-frequency interference (RFI) exists on site, which not only makes ... More
The Mass Function of Supermassive Black Holes in the Direct-collapse ScenarioJun 12 2019One of the ideas to explain the existence of supermassive black holes (SMBH) that are in place by z~7 is that there was an earlier phase of very rapid accretion onto direct collapse black holes (DCBH) that started their lives with masses ~ 10^4-10^5 M_solar. ... More
Dynamics of magnetic flux tubes in accretion discs of T Tauri starsJun 12 2019Dynamics of slender magnetic flux tubes (MFT) in the accretion discs of T Tauri stars is investigated. We perform simulations taking into account buoyant, aerodynamic and turbulent drag forces, radiative heat exchange between MFT and ambient gas, magnetic ... More
Impact of electron capture rates on nuclei far from stability on core-collapse supernovaeJun 12 2019The impact of electron-capture (EC) cross sections on neutron-rich nuclei on the dynamics of core-collapse during infall and early post-bounce is studied performing spherically symmetric simulations in general relativity using a multigroup scheme for ... More
A Thousand Earths: A Very Large Aperture, Ultralight Space Telescope Array for Atmospheric Biosignature SurveysJun 12 2019An outstanding, multi-disciplinary goal of modern science is the study of the diversity of potentially Earth-like planets and the search for life in them. This goal requires a bold new generation of space telescopes, but even the most ambitious designs ... More
The Discovery of Six Recycled Pulsars from the Arecibo 327-MHz Drift-Scan Pulsar SurveyJun 12 2019Recycled pulsars are old ($\gtrsim10^{8}$ yr) neutron stars that are descendants from close, interacting stellar systems. In order to understand their evolution and population, we must find and study the largest number possible of recycled pulsars in ... More
Estimation and correction of the instrumental perturbations of Vainu Bappu Telescope Echelle spectrograph using a model-based approachJun 12 2019The Echelle spectrograph operating at Vainu Bappu Telescope (VBT), India, is a general purpose instrument used for many high-resolution spectroscopic observations. A concerted effort is being made to expand the scientific capability of the instrument ... More
Greening of the Brown Dwarf Desert. EPIC 212036875 b -- a 51 M$_\mathrm{J}$ object in a 5 day orbit around an F7 V starJun 12 2019Jun 13 2019Our aim is to investigate the nature and formation of brown dwarfs by adding a new well-characterised object to the small sample of less than 20 transiting brown dwarfs. One brown dwarf candidate was found by the KESPRINT consortium when searching for ... More
Greening of the Brown Dwarf Desert. EPIC 212036875 b -- a 51 M$_\mathrm{J}$ object in a 5 day orbit around an F7 V starJun 12 2019Our aim is to investigate the nature and formation of brown dwarfs by adding a new well-characterised object to the small sample of less than 20 transiting brown dwarfs. One brown dwarf candidate was found by the KESPRINT consortium when searching for ... More
Lensing anomalies from the epoch of reionisationJun 12 2019Reionisation blurring is a non-linear correction to the cosmic microwave background that acts similar to weak gravitational lensing and that can be computed from linear perturbations through a blurring potential. Its impact on the cosmic microwave background ... More
Current Status of r-Process NucleosynthesisJun 12 2019The rapid neutron capture process (r process) is believed to be responsible for about half of the production of the elements heavier than iron and contributes to abundances of some lighter nuclides as well. A universal pattern of r-process element abundances ... More
Constraints on the emission region of 3C 279 during strong flares in 2014 and 2015 through VHE gamma-ray observations with H.E.S.SJun 12 2019The flat spectrum radio quasar 3C 279 is known to exhibit pronounced variability in the high-energy ($100\,$MeV$<E<100\,$GeV) $\gamma$-ray band, which is continuously monitored with Fermi-LAT. During two periods of high activity in April 2014 and June ... More
Gravitational scalar field with a RAQUAL-like cubic kinetic term and second order self-interactionJun 12 2019The consequences of two unorthodox contributions to the Lagrangian of a (real valued) relativistic scalar field are studied: a cubic kinetic term similar to the "a-quadratic" Lagrangian used in the first attempt of a covariant generalization of Milgrom's ... More
Multiple Stellar Populations in NGC 2808: a Case Study for Cluster AnalysisJun 12 2019In the massive globular cluster NGC 2808, RGB stars form at least five distinct groups in the so-called chromosome map photometric plane, arguably corresponding to different stellar populations. While a human expert can separate the groups by eye relatively ... More
Coordinate independent approach to the calculation of the effects of local structure on the luminosity distanceJun 12 2019Local structure can have important effects on luminosity distance observations, which could for example affect the local estimation of the Hubble constant based on low red-shift type Ia supernovae. Using a spherically symmetric exact solution of the Eistein's ... More
Relativistic wind accretion on to a Schwarzschild black holeJun 12 2019We present a novel analytic model of relativistic wind accretion on to a Schwarzschild black hole. This model constitutes a general relativistic extension of the classical model of wind accretion by Bondi, Hoyle, and Lyttleton (BHL). As in BHL, this model ... More
The Effect of Binarity on Circumstellar Disk EvolutionJun 12 2019We present new results on how the presence of stellar companions affects disk evolution based on a study of the 5-11 Myr old Upper Scorpius OB Association. Of the 50 G0-M3 Upper Sco members with disks in our sample, only seven host a stellar companion ... More
Influence of 3D plasmoid dynamics on the transition from collisional to kinetic reconnectionJun 12 2019Within the resistive magnetohydrodynamic model, high-Lundquist number reconnection layers are unstable to the plasmoid instability, leading to a turbulent evolution where the reconnection rate can be independent of the underlying resistivity. However, ... More
Primordial Extremal Black Holes as Dark MatterJun 11 2019We show that primordial (nearly) extremal black holes with a wide range of masses from the Planck scale to around $10^9$ g could be cosmologically stable and explain dark matter, given a dark electromagnetism and a heavy dark electron. For individual ... More
Circumnuclear rings and Lindblad resonances in spiral galaxiesJun 11 2019In order to study the location of circumnuclear rings (CNR) and their possible relation with the inner Lindblad resonances (ILR), we investigate a sample of spiral galaxies. For this purpose, we have obtained and analyzed medium resolution spectra of ... More
Hard state accretion disk winds from black holes: the revealing case of MAXI J1820+070Jun 11 2019We report on a detailed optical spectroscopic follow-up of the black hole transient MAXI J1820+070 (ASASSN-18ey). The observations cover the main part of the X-ray binary outburst, when the source alternated between hard and soft states following the ... More
Photometry of Beta Lyrae in 2018 by the BRITE satellitesJun 11 2019Observations of Beta Lyr in four months of 2018 by three BRITE Constellation satellites (the red-filter BTr and BHr, and the blue-filter BLb) permitted a first, limited look into the light-curve variability in two spectral bands. The variations were found ... More
Effects of the magnetic field direction on the Tsallis statisticJun 11 2019We extend the use of the Tsallis statistic to measure the differences in gas dynamics relative to the mean magnetic field present from natural eddy-type motions existing in magnetohydrodynamical (MHD) turbulence. The variation in gas dynamics was estimated ... More
Kinetics and clustering of dust particles in supersonic turbulence with self-gravityJun 11 2019We present a simulation of isothermal supersonic (rms Mach number $\mathcal{M}_{\rm rms} \sim 3$) turbulent gas with inertial particles (dust) and self-gravity in statistical steady-state, which we compare with a corresponding simulation without self-gravity. ... More
Disentangling Planets from Photoelectric Instability in Gas-Rich Optically Thin Dusty DisksJun 11 2019Structures in circumstellar disks such as gaps and rings are often attributed to planets. This connection has been difficult to show unequivocally, as other processes may also produce these features. Particularly, a photoelectric instability (PEI) has ... More
Generalized Proca and its Constraint AlgebraJun 11 2019We reconsider the construction of general derivative self-interactions for a massive Proca field. The constructed Lagrangian is such that the vector field propagates at most three degrees of freedom, thus avoiding the ghostly nature of a fourth polarisation. ... More
Detailed chemical composition and orbit of the new globular cluster FSR1758: Implications for the accretion of the Sequoia dwarf galaxy onto the Milky WayJun 11 2019We present detailed chemical abundances, radial velocities and orbital parameters for FSR 1758, a recently discovered star cluster in the direction of the Galactic Bulge. High resolution (R~42,000) spectra were obtained using the Magellan/Clay telescope ... More
Discovery of a 2.8 s pulsar in a 2 d orbit High-Mass X-ray Binary powering the Ultraluminous X-ray source ULX-7 in M51Jun 11 2019Jun 13 2019We discovered 2.8 s pulsations in the X-ray emission of the ultraluminous X-ray source (ULX) M51 ULX-7 within the UNSEeN project, which was designed to hunt for new pulsating ULXs (PULXs) with XMM-Newton. The pulse shape is sinusoidal and large variations ... More
Discovery of a 2.8 s pulsar in a 2 d orbit High-Mass X-ray Binary powering the Ultraluminous X-ray source ULX-7 in M51Jun 11 2019We discovered 2.8 s pulsations in the X-ray emission of the ultraluminous X-ray source (ULX) M51 ULX-7 within the UNSEeN project, which was designed to hunt for new pulsating ULXs (PULXs) with XMM-Newton. The pulse shape is sinusoidal and large variations ... More
CMB foreground measurements through broad-band radio spectro-polarimetry: prospects of the SKA-MPG telescopeJun 11 2019Precise measurement of the foreground synchrotron emission, which contaminates the faint polarized cosmic microwave background radiation (CMB), is a major challenge for the next-generation of CMB experiments. To address this, dedicated foreground measurement ... More
Identifying resonances of the Galactic bar in Gaia DR2: Clues from action spaceJun 11 2019Action space synthesizes the orbital information of stars and is well-suited to analyse the rich amount of kinematic disk substructure in the Gaia DR2 radial velocity sample (RVS). In this work, we revisit one of the strongest perturbers in the Milky ... More
Dissecting a disk-instability outburst in a symbiotic star: $NuSTAR$, and $Swift$ observations of T Coronae Borealis during the rise to the "super-active" stateJun 11 2019The current $super-active$ state of the recurrent nova T CrB has been observed with unprecedented detail. Previously published observations provide strong evidence that this state is due to an enhancement of the flow of material through the accretion ... More
Globular clusters as probes of dark matter cusp-core transformationsJun 11 2019Bursty star formation in dwarf galaxies can slowly transform a steep dark matter cusp into a constant density core. We explore the possibility that globular clusters (GCs) retain a dynamical memory of this transformation. To test this, we use the nbody6df ... More