Results for "P. Dominis Prester"

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The VHE Gamma-Ray View of the FSRQ PKS~1510-089Mar 20 2019The flat spectrum radio quasar PKS 1510-089 is a monitored target in many wavelength bands due to its high variability. It was detected as a very-high-energy (VHE) $\gamma$-ray emitter with H.E.S.S. in 2009, and has since been a regular target of VHE ... More
All-Sky-ASTROGAM: The MeV Gamma-Ray Companion to Multimessenger AstronomyMay 19 2019All-Sky-ASTROGAM is a gamma-ray observatory operating in a broad energy range, 100 keV to a few hundred MeV, recently proposed as the "Fast" (F) mission of the European Space Agency for a launch in 2028 to an L2 orbit. The scientific payload is composed ... More
Latest MAGIC discoveries pushing redshift boundaries in VHE AstrophysicsJun 14 2016The search for detection of gamma-rays from distant AGNs by Imaging Atmospheric Cherenkov Telescopes (IACTs) is challenging at high redshifts, not only because of lower flux due to the distance of the source, but also due to the consequent absorption ... More
alpha'-exact entropies for BPS and non-BPS extremal dyonic black holes in heterotic string theory from ten-dimensional supersymmetrySep 29 2008Dec 10 2008We calculate near-horizon solutions for four-dimensional 4-charge and five-dimensional 3-charge black holes in heterotic string theory from the part of the ten-dimensional tree-level effective action which is connected to gravitational Chern-Simons term ... More
Worldline quantization of field theory, effective actions and $L_\infty$ structureFeb 08 2018We formulate the worldline quantization of a massive fermion model coupled to external higher spin sources. We use the relations obtained in this way to show that its regularized effective action is endowed with an $L_\infty$ symmetry. The same result ... More
Gravitational Chern-Simons terms and black hole entropy. Global aspectsJul 30 2012Oct 10 2012We discuss the topological and global gauge properties of the formula for a black hole entropy due to a purely gravitational Chern-Simons term. We study under what topological and geometrical conditions this formula is well-defined. To this end we have ... More
One-loop effective actions and higher spinsSep 07 2016Nov 14 2016The idea we advocate in this paper is that the one-loop effective action of a free (massive) field theory coupled to external sources (via conserved currents) contains complete information about the classical dynamics of such sources. We show many explicit ... More
Massive fermion model in 3d and higher spin currentsFeb 23 2016May 12 2016We analyze the 3d free massive fermion theory coupled to external sources. The presence of a mass explicitly breaks parity invariance. We calculate two- and three-point functions of a gauge current and the energy momentum tensor and, for instance, obtain ... More
Worldline quantization of field theory, effective actions and $L_\infty$ structureFeb 08 2018May 11 2018We formulate the worldline quantization of a massive fermion model coupled to external higher spin sources. We use the relations obtained in this way to show that its regularized effective action is endowed with an $L_\infty$ symmetry. The same result ... More
Axial gravity, massless fermions and trace anomaliesMar 30 2017May 24 2017This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background ... More
Axial gravity: a non-perturbative approach to split anomaliesJul 03 2018Jul 04 2018In a theory of a Dirac fermion field coupled to a metric-axial-tensor (MAT) background, using a Schwinger-DeWitt heat kernel technique, we compute non-perturbatively the two (odd parity) trace anomalies. A suitable collapsing limit of this model corresponds ... More
One-loop effective actions and higher spins. IISep 06 2017In this paper we continue and improve the analysis of the effective actions obtained by integrating out a scalar and a fermion field coupled to external symmetric sources, started in the previous paper. The first subject we study is the geometrization ... More
HS in flat spacetime. YM-like modelsDec 12 2018Dec 16 2018We introduce and analyze a few examples of massless higher spin theories in Minkowski spacetime. They are defined in terms of master fields, i.e. fields defined in the whole phase space. More specifically we introduce the HS YM-like theories in any dimension ... More
HS in flat spacetime. The effective action methodNov 12 2018Mar 29 2019This is the first paper in a series of three dealing with HS theories in flat spacetime. It is divided in three parts. The first part is an elaboration on the method of effective action, initiated in a previous paper. We study the properties of correlators ... More
One-loop effective actions and higher spinsSep 07 2016Sep 15 2016The idea we advocate in this paper is that the one-loop effective action of a free (massive) field theory coupled to external sources (via conserved currents) contains complete information about the classical dynamics of such sources. We show many explicit ... More
Does three dimensional electromagnetic field inherit the spacetime symmetries?Aug 13 2015Mar 28 2016We prove that the electromagnetic field in a (1+2)-dimensional spacetime necessarily inherits the symmetries of the spacetime metric in a large class of generalized Einstein-Maxwell theories. The Lagrangians of the studied theories have general diff-covariant ... More
alpha'^2-corrections to extremal dyonic black holes in heterotic string theoryOct 20 2007May 21 2008We calculate alpha'^2-corrections to the entropy of the 5-dimensional 3-charge and the 4-dimensional 4-charge large extremal black holes using the low energy effective action of the heterotic string theory. In the 4-dimensional case, our results are in ... More
Reanalyses of Anomalous Gravitational Microlensing Events in the OGLE-III Early Warning System Database with Combined DataFeb 24 2015Mar 02 2015We reanalyze microlensing events in the published list of anomalous events that were observed from the OGLE lensing survey conducted during 2004-2008 period. In order to check the existence of possible degenerate solutions and extract extra information, ... More
Extremal black holes in D=5: SUSY vs. Gauss-Bonnet correctionsJun 08 2007Nov 10 2007We analyse near-horizon solutions and compare the results for the black hole entropy of five-dimensional spherically symmetric extremal black holes when the N=2 SUGRA actions are supplied with two different types of higher-order corrections: (1) supersymmetric ... More
Observation of the Black Widow B1957+20 millisecond pulsar binary system with the MAGIC telescopesJun 05 2017B1957+20 is a millisecond pulsar located in a black widow type compact binary system with a low mass stellar companion. The interaction of the pulsar wind with the companion star wind and/or the interstellar plasma is expected to create plausible conditions ... More
A Super-Jupiter orbiting a late-type star: A refined analysis of microlensing event OGLE-2012-BLG-0406Oct 09 2013Dec 05 2013We present a detailed analysis of survey and follow-up observations of microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive coverage of the lightcurve, especially the perturbation part, allowed us to ... More
Teraelectronvolt pulsed emission from the Crab pulsar detected by MAGICOct 23 2015Dec 05 2018Aims: To investigate the extension of the very-high-energy spectral tail of the Crab pulsar at energies above 400 GeV. Methods: We analyzed $\sim$320 hours of good quality data of Crab with the MAGIC telescope, obtained from February 2007 until April ... More
Symmetries and gravitational Chern-Simons Lagrangian termsMay 02 2013We consider some general consequences of adding pure gravitational Chern-Simons term to manifestly diff-covariant theories of gravity. Extending the result of a previous paper we enlarge the class of metrics for which the inclusion of a gCS term in the ... More
Stationary rotating black holes in theories with gravitational Chern-Simons Lagrangian termOct 15 2012Jan 15 2013We study the effects of introducing purely gravitational Chern-Simons Lagrangian terms in ordinary Einstein gravity on stationary rotating black hole solutions and on the associated thermodynamical properties, in a generic number of dimensions which support ... More
Characterizing Lenses and Lensed Stars of High-Magnification Single-lens Gravitational Microlensing Events With Lenses Passing Over Source StarsNov 17 2011Mar 20 2012We present the analysis of the light curves of 9 high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2009-BLG-174, ... More
MAGIC observations of the giant radio galaxy M87 in a low emission state between 2005 and 2007Sep 27 2011We present the results of a long M87 monitoring campaign in very high energy $\gamma$-rays with the MAGIC-I Cherenkov telescope. A total of 150 hours of data was gathered between 2005 and 2007. No flaring activity was found during that time. Nevertheless, ... More
Parity-odd surface anomalies and correlation functions on conical defectsMar 20 2015Dec 01 2015We analyse the parity-odd ("type P") surface anomalies of the energy-momentum tensor correlators in conformal field theories, with an emphasis on d=4 and d=3 dimensional spacetimes. Using cohomology analysis we construct the expression for the most general ... More
Gravitational Chern-Simons Lagrangian terms and spherically symmetric spacetimesMay 24 2011Feb 03 2012We show that for general spherically symmetric configurations, contributions of general gravitational and mixed gauge-gravitational Chern-Simons terms to the equations of motion vanish identically in $D>3$ dimensions. This implies that such terms in the ... More
Gravitational Chern-Simons Lagrangians and black hole entropyApr 13 2011Apr 29 2011We analyze the problem of defining the black hole entropy when Chern-Simons terms are present in the action. Extending previous works, we define a general procedure, valid in any odd dimensions both for purely gravitational CS terms and for mixed gauge-gravitational ... More
Five-dimensional black holes in heterotic string theoryNov 30 2007We review recent results on near-horizon static black hole solutions and entropy in R^2-corrected N=2 SUGRA in D=5, focusing on actions connected to heterotic string compactified on K3\times S^1. Comparison with \alpha'-perturbative results, results obtained ... More
Conformal entropy as a consequence of the properties of stationary Killing horizonsJun 22 2004Dec 10 2004We show that microscopic black hole entropy formula based on Virasoro algebra can be derived from usual properties of stationary Killing horizons alone and absence of singularities of curvature invariants on them. In such a way some usual additional assumptions ... More
Horizon conformal entropy in Gauss-Bonnet gravityJul 30 2002Oct 08 2002We treat spherically symmetric black holes in Gauss-Bonnet gravity by imposing boundary conditions on fluctuating metric on the horizon. Obtained effective two-dimensional theory admits Virasoro algebra near the horizon. This enables, with the help of ... More
Entropy of Killing horizons from Virasoro algebra in D-dimensional extended Gauss-Bonnet gravityDec 03 2002We treat D-dimensional black holes with Killing horizon for extended Gauss-Bonnet gravity. We use Carlip method and impose boundary conditions on horizon what enables us to identify Virasoro algebra and evaluate its central charge and Hamiltonian eigenvalue. ... More
Difference imaging photometry of blended gravitational microlensing events with a numerical kernelMay 18 2009The numerical kernel approach to difference imaging has been implemented and applied to gravitational microlensing events observed by the PLANET collaboration. The effect of an error in the source-star coordinates is explored and a new algorithm is presented ... More
SUSY a consequence of smoothness?Jul 29 2001The consequences of certain simple assumptions like smoothness of ground state properties and vanishing of the vacuum energy (at least perturbatively) are explored. It would be interesting from the point of view of building realistic theories to obtain ... More
Microscopic interpretation of black hole entropyMay 10 2004Jun 25 2004It is shown, using conformal symmetry methods, that one can obtain microscopic interpretation of black hole entropy for general class of higher curvature Lagrangians.
Higher curvature Lagrangians, conformal symmetry and microscopic entropy of Killing horizonsJun 03 2003We impose a certain class of boundary conditions on Killing horizon and show for Lagrangians with arbitrary curvature dependence that one can identify a Virasoro algebra with nontrivial central charge and calculable Hamiltonian eigenvalue. Entropy can ... More
RoboNet-II: Follow-up observations of microlensing events with a robotic network of telescopesAug 06 2008Oct 24 2008RoboNet-II uses a global network of robotic telescopes to perform follow-up observations of microlensing events in the Galactic Bulge. The current network consists of three 2m telescopes located in Hawaii and Australia (owned by Las Cumbres Observatory) ... More
Towards A Census of Earth-mass Exo-planets with Gravitational MicrolensingJul 31 2008Thirteen exo-planets have been discovered using the gravitational microlensing technique (out of which 7 have been published). These planets already demonstrate that super-Earths (with mass up to ~10 Earth masses) beyond the snow line are common and multiple ... More
Combining Spitzer parallax and Keck II adaptive optics imaging to measure the mass of a solar-like star orbited by a cold gaseous planet discovered by microlensingSep 04 2017To obtain accurate mass measurements for cold planets discovered by microlensing, it is usually necessary to combine light curve modeling with at least two lens mass-distance relations. Often, a constraint on the Einstein ring radius measurement is obtained ... More
The exceptional VHE gamma-ray outburst of PKS 1510-089 in May 2016Aug 02 2017PKS 1510-089 (z=0.361) is one of only a handful of flat spectrum radio quasars that have been detected at very high energy (VHE, $E>100\,$GeV) gamma rays. It is a very active source across the entire electromagnetic spectrum. VHE observations in May 2016 ... More
MAGIC and Fermi-LAT gamma-ray results on unassociated HAWC sourcesJan 13 2019The HAWC Collaboration released the 2HWC catalog of TeV sources, in which 19 show no association with any known high-energy (HE; E > 10 GeV) or very-high-energy (VHE; E > 300 GeV) sources. This catalog motivated follow-up studies by both the MAGIC and ... More
Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layoutApr 02 2019The Cherenkov Telescope Array (CTA) is the major next-generation observatory for ground-based very-high-energy gamma-ray astronomy. It will improve the sensitivity of current ground-based instruments by a factor of five to twenty, depending on the energy, ... More
Ruthenocuprates: Intrinsic magnetic multilayersJul 18 2001Jul 19 2001We report ac susceptibility measurements on polycrystalline samples of SrRuO_3 and three ruthenocuprates: superconducting RuSr_2GdCu_2O_8 (Ru-1212), superconducting RuSr_2Eu_(2-x)Ce_xCu_2O_y (Ru-1222, x=0.5) and nonsuperconducting, insulating RuSr_2Eu_(2-x)Ce_xCu_2O_z ... More
Detection of very-high-energy gamma rays from the most distant and gravitationally lensed blazar QSO B0218+357 using the MAGIC telescope systemAug 19 2015QSO B0218+357 is a blazar located at a cosmological redshift of z=0.944. It is gravitationally lensed by a spiral galaxy at a redshift of z=0.68. The blazar and its lens are well studied in the radio through X-ray bands, and several blazar outbursts were ... More
One or more bound planets per Milky Way star from microlensing observationsFeb 04 2012Most known extrasolar planets (exoplanets) have been discovered using the radial velocity$^{\bf 1,2}$ or transit$^{\bf 3}$ methods. Both are biased towards planets that are relatively close to their parent stars, and studies find that around 17--30% (refs ... More
A systematic fitting scheme for caustic-crossing microlensing eventsJan 09 2009We outline a method for fitting binary-lens caustic-crossing microlensing events based on the alternative model parameterisation proposed and detailed in Cassan (2008). As an illustration of our methodology, we present an analysis of OGLE-2007-BLG-472, ... More
Slow fracton modes in antiferromagnetic correlations of high-Tc superconductorsNov 29 1999Jul 30 2001In cuprate superconductors superconductivity develops as a unique cross over between the two extremal phases characterizing these compounds. The extremal phases are known to be an antiferromagnetic (AF) Mott insulator one, on one side, and a non-superconducting ... More
Experimental evidence of a fractal dissipative regime in high-T_c superconductorsMay 07 1999May 11 1999We report on our experimental evidence of a substantial geometrical ingredient characterizing the problem of incipient dissipation in high-T_c superconductors(HTS): high-resolution studies of differential resistance-current characteristics in absence ... More
Ferromagnetism in Co7(TeO3)4Br6: A byproduct of complex antiferromagnetic order and single-ion anisotropyJan 30 2009Pronounced anisotropy of magnetic properties and complex magnetic order of a new oxi-halide compound Co7(TeO3)4Br6 has been investigated by powder and single crystal neutron diffraction, magnetization and ac susceptibility techniques. Anisotropy of susceptibility ... More
Cherenkov Telescope Array Contributions to the 35th International Cosmic Ray Conference (ICRC2017)Sep 11 2017Oct 24 2017List of contributions from the Cherenkov Telescope Array Consortium presented at the 35th International Cosmic Ray Conference, July 12-20 2017, Busan, Korea.
CTA contributions to the 33rd International Cosmic Ray Conference (ICRC2013)Jul 08 2013Jul 29 2013Compilation of CTA contributions to the proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), which took place in 2-9 July, 2013, in Rio de Janeiro, Brazil
The First Planetary Microlensing Event with Two Microlensed Source StarsJul 30 2017Mar 22 2018We present the analysis of microlensing event MOA-2010-BLG-117, and show that the light curve can only be explained by the gravitational lensing of a binary source star system by a star with a Jupiter mass ratio planet. It was necessary to modify standard ... More
OGLE-2005-BLG-018: Characterization of Full Physical and Orbital Parameters of a Gravitational Binary LensApr 27 2011We present the analysis result of a gravitational binary-lensing event OGLE-2005-BLG-018. The light curve of the event is characterized by 2 adjacent strong features and a single weak feature separated from the strong features. The light curve exhibits ... More
MOA-2007-BLG-197: Exploring the brown dwarf desertMay 22 2015We present the analysis of MOA-2007-BLG-197Lb, the first brown dwarf companion to a Sun-like star detected through gravitational microlensing. The event was alerted and followed-up photometrically by a network of telescopes from the PLANET, MOA, and uFUN ... More
Limb-darkening measurements for a cool red giant in microlensing event OGLE 2004-BLG-482Dec 11 2009Sep 28 2010Aims: We present a detailed analysis of OGLE 2004-BLG-482, a relatively high-magnification single-lens microlensing event which exhibits clear extended-source effects. These events are relatively rare, but they potentially contain unique information on ... More
Non-uniform doping across the Fermi surface of NbS$_2$ intercalatesNov 08 2006Jul 19 2007Magnetic ordering of the first row transition metal intercalates of NbS$_2$ due to coupling between the conduction electrons and the intercalated ions has been explained in terms of Fermi surface nesting. We use angle-resolved photoelectron spectroscopy ... More
Contributions of the Cherenkov Telescope Array (CTA) to the 6th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2016)Oct 17 2016List of contributions from the Cherenkov Telescope Array (CTA) Consortium presented at the 6th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2016), July 11-15, 2016, in Heidelberg, Germany.
CTA Contributions to the 34th International Cosmic Ray Conference (ICRC2015)Aug 24 2015Sep 11 2015List of contributions from the CTA Consortium presented at the 34th International Cosmic Ray Conference, 30 July - 6 August 2015, The Hague, The Netherlands.
Interpretation of a Short-Term Anomaly in the Gravitational Microlensing Event MOA-2012-BLG-486Aug 27 2013A planetary microlensing signal is generally characterized by a short-term perturbation to the standard single lensing light curve. A subset of binary-source events can produce perturbations that mimic planetary signals, thereby introducing an ambiguity ... More
A Cold Neptune-Mass Planet OGLE-2007-BLG-368Lb: Cold Neptunes Are CommonDec 07 2009Jan 22 2010We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with a planet-star mass ratio of q=[9.5 +/- 2.1] x 10^{-5} via gravitational microlensing. The planetary deviation was detected in real-time thanks to the high cadence of the MOA survey, ... More
OGLE-2008-BLG-510: first automated real-time detection of a weak microlensing anomaly - brown dwarf or stellar binary?Mar 06 2012The microlensing event OGLE-2008-BLG-510 is characterised by an evident asymmetric shape of the peak, promptly detected by the ARTEMiS system in real time. The skewness of the light curve appears to be compatible both with binary-lens and binary-source ... More
A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic BulgeDec 13 2013We present the first microlensing candidate for a free-floating exoplanet-exomoon system, MOA-2011-BLG-262, with a primary lens mass of M_host ~ 4 Jupiter masses hosting a sub-Earth mass moon. The data are well fit by this exomoon model, but an alternate ... More
Mass measurement of a single unseen star and planetary detection efficiency for OGLE 2007-BLG-050Jul 20 2009Jul 22 2009We analyze OGLE-2007-BLG-050, a high magnification microlensing event (A ~ 432) whose peak occurred on 2 May, 2007, with pronounced finite-source and parallax effects. We compute planet detection efficiencies for this event in order to determine its sensitivity ... More
Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictionsJan 17 2011We present the first example of binary microlensing for which the parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possible by a confluence of two relatively unusual circumstances. First, the binary ... More
OGLE-2005-BLG-071Lb, the Most Massive M-Dwarf Planetary Companion?Apr 09 2008Jun 03 2009We combine all available information to constrain the nature of OGLE-2005-BLG-071Lb, the second planet discovered by microlensing and the first in a high-magnification event. These include photometric and astrometric measurements from Hubble Space Telescope, ... More
A possible binary system of a stellar remnant in the high magnification gravitational microlensing event OGLE-2007-BLG-514Jul 05 2012We report the extremely high magnification (A > 1000) binary microlensing event OGLE-2007-BLG-514. We obtained good coverage around the double peak structure in the light curve via follow-up observations from different observatories. The binary lens model ... More
Red noise versus planetary interpretations in the microlensing event OGLE-2013-BLG-446Oct 09 2015Oct 28 2015For all exoplanet candidates, the reliability of a claimed detection needs to be assessed through a careful study of systematic errors in the data to minimize the false positives rate. We present a method to investigate such systematics in microlensing ... More
The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)cSep 21 2016We present the analysis of the first circumbinary planet microlensing event, OGLE-2007-BLG-349. This event has a strong planetary signal that is best fit with a mass ratio of $q \approx 3.4\times 10^{-4}$, but there is an additional signal due to an additional ... More
Initial dissipation and current-voltage characteristics of superconductors containing fractal clusters of a normal phaseApr 16 2003Dec 27 2004The influence of fractal clusters of a normal phase on distinctive features of current-voltage characteristic of percolative type-II superconductors is considered. The results of high-resolution measurements of the differential resistance of BPSCCO/Ag ... More
Pathway to the Galactic Distribution of Planets: Combined Spitzer and Ground-Based Microlens Parallax Measurements of 21 Single-Lens EventsNov 26 2014Feb 24 2015We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was ~1 AU West of Earth in projection. We combine these measurements with a ... More
The First Circumbinary Planet Found by Microlensing: OGLE-2007-BLG-349L(AB)cSep 21 2016Nov 03 2016We present the analysis of the first circumbinary planet microlensing event, OGLE-2007-BLG-349. This event has a strong planetary signal that is best fit with a mass ratio of $q \approx 3.4\times10^{-4}$, but there is an additional signal due to an additional ... More
Incommensurate magnetic ordering in Cu2Te2O5X2 (X=Cl, Br) studied by single crystal neutron diffractionDec 23 2005Polarized and unpolarized neutron diffraction studies have been carried out on single crystals of the coupled spin tetrahedra systems Cu2Te2O5X2 (X=Cl, Br). A model of the magnetic structure associated with the propagation vectors k'Cl ~ -0.150,0.422,1/2 ... More
A Giant Planet beyond the Snow Line in Microlensing Event OGLE-2011-BLG-0251Mar 05 2013We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting microlensing observations towards the Galactic Bulge. Based on detailed modelling ... More
MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended lightMay 29 2012Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet ... More
MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detectionOct 22 2012Oct 10 2013We analyze MOA-2010-BLG-311, a high magnification (A_max>600) microlensing event with complete data coverage over the peak, making it very sensitive to planetary signals. We fit this event with both a point lens and a 2-body lens model and find that the ... More
MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf BoundaryNov 16 2012Dec 11 2012We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010-03-18. This event was remarkable because the source was previously known to be photometrically variable. ... More
MOA-2010-BLG-328Lb: a sub-Neptune orbiting very late M dwarf ?Sep 30 2013Oct 10 2013We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and planetary masses of Mh = 0.11+/-0.01 M_{sun} and Mp = 9.2+/-2.2M_Earth, corresponding to a very late M dwarf and sub-Neptune-mass planet, respectively. The system ... More
A New Type of Ambiguity in the Planet and Binary Interpretations of Central Perturbations of High-Magnification Gravitational Microlensing EventsApr 21 2012Apr 25 2012High-magnification microlensing events provide an important channel to detect planets. Perturbations near the peak of a high-magnification event can be produced either by a planet or a binary companion. It is known that central perturbations induced by ... More
MOA-2010-BLG-523: "Failed Planet" = RS CVn StarOct 22 2012Oct 26 2012The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing lightcurve near the peak of an Amax ~ 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for ... More
The blazar TXS 0506+056 associated with a high-energy neutrino: insights into extragalactic jets and cosmic ray accelerationJul 11 2018Jul 30 2018A neutrino with energy of $\sim$290 TeV, IceCube-170922A, was detected in coincidence with the BL Lac object TXS~0506+056 during enhanced gamma-ray activity, with chance coincidence being rejected at $\sim 3\sigma$ level. We monitored the object in the ... More
Microlensing Discovery of a Population of Very Tight, Very Low-mass Binary Brown DwarfsFeb 18 2013Mar 20 2013Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass of the brown-dwarf mass function provide critical empirical diagnostics ... More
Characterizing Low-Mass Binaries From Observation of Long Time-scale Caustic-crossing Gravitational Microlensing EventsApr 13 2012Jun 13 2012Despite astrophysical importance of binary star systems, detections are limited to those located in small ranges of separations, distances, and masses and thus it is necessary to use a variety of observational techniques for a complete view of stellar ... More
Discovery of TeV gamma-ray emission from the pulsar wind nebula 3C 58 by MAGICMay 23 2014Jul 09 2014The pulsar wind nebula (PWN) 3C 58 is one of the historical very-high-energy (VHE; E>100 GeV) gamma-ray source candidates. It is energized by one of the highest spin-down power pulsars known (5% of Crab pulsar) and it has been compared to the Crab Nebula ... More
Performance of the MAGIC telescopes under moonlightApr 04 2017Aug 02 2017MAGIC, a system of two imaging atmospheric Cherenkov telescopes, achieves its best performance under dark conditions, i.e. in absence of moonlight or twilight. Since operating the telescopes only during dark time would severely limit the duty cycle, observations ... More
Search for very-high-energy gamma-ray emission from the microquasar Cygnus X-1 with the MAGIC telescopesAug 11 2017The microquasar Cygnus X-1 displays the two typical soft and hard X-ray states of a black-hole transient. During the latter, Cygnus X-1 shows a one-sided relativistic radio-jet. Recent detection of the system in the high energy (HE; $E\gtrsim60$ MeV) ... More
OGLE-2011-BLG-0265Lb: a Jovian Microlensing Planet Orbiting an M DwarfOct 30 2014Feb 24 2015We report the discovery of a Jupiter-mass planet orbiting an M-dwarf star that gave rise to the microlensing event OGLE-2011-BLG-0265. Such a system is very rare among known planetary systems and thus the discovery is important for theoretical studies ... More
Indirect dark matter searches in the dwarf satellite galaxy Ursa Major II with the MAGIC TelescopesDec 07 2017Mar 09 2018The dwarf spheroidal galaxy Ursa Major II (UMaII) is believed to be one of the most dark-matter dominated systems among the Milky Way satellites and represents a suitable target for indirect dark matter (DM) searches. The MAGIC telescopes carried out ... More
MAGIC observations of MWC 656, the only known Be/BH systemFeb 05 2015Feb 09 2015Context: MWC 656 has recently been established as the first observationally detected high-mass X-ray binary system containing a Be star and a black hole (BH). The system has been associated with a gamma-ray flaring event detected by the AGILE satellite ... More
OGLE 2008--BLG--290: An accurate measurement of the limb darkening of a Galactic Bulge K Giant spatially resolved by microlensingMay 06 2010Gravitational microlensing is not only a successful tool for discovering distant exoplanets, but it also enables characterization of the lens and source stars involved in the lensing event. In high magnification events, the lens caustic may cross over ... More
MAGIC Contributions to the 35th International Cosmic Ray Conference (ICRC2017)Aug 17 2017Sep 14 2017MAGIC (Major Atmospheric Gamma Imaging Cherenkov) is a system of two 17 m diameter, F/1.03 Imaging Atmospheric Cherenkov Telescopes (IACT). They are dedicated to the observation of gamma rays from galactic and extragalactic sources in the very high energy ... More
Discovery and Mass Measurements of a Cold, 10-Earth Mass Planet and Its Host StarJun 10 2011We present the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, made with the gravitational microlensing method. This planet has a mass of m_p = 10.4 +- 1.7 Earth masses and orbits a star of mass M_* = 0.56 +- 0.09 Solar ... More
A cut-off in the TeV gamma-ray spectrum of the SNR Cassiopeia AJul 05 2017It is widely believed that the bulk of the Galactic cosmic rays are accelerated in supernova remnants (SNRs). However, no observational evidence of the presence of particles of PeV energies in SNRs has yet been found. The young historical SNR Cassiopeia ... More
MAGIC observations of the microquasar V404 Cygni during the 2015 outburstJul 04 2017The microquasar V404 Cygni underwent a series of outbursts in 2015, June 15-31, during which its flux in hard X-rays (20-40 keV) reached about 40 times the Crab Nebula flux. Because of the exceptional interest of the flaring activity from this source, ... More
MAGIC observations of the February 2014 flare of 1ES 1011+496 and ensuing constraint of the EBL densityFeb 16 2016Feb 18 2016In February-March 2014, the MAGIC telescopes observed the high-frequency peaked BL Lac 1ES 1011+496 (z=0.212) in flaring state at very-high energy (VHE, E>100GeV). The flux reached a level more than 10 times higher than any previously recorded flaring ... More
Limits on the flux of tau neutrinos from 1 PeV to 3 EeV with the MAGIC telescopesMay 07 2018A search for tau neutrino induced showers with the MAGIC telescopes is presented. The MAGIC telescopes located at an altitude of 2200 m a.s.l. in the Canary Island of La Palma, can point towards the horizon or a few degrees below across an azimuthal range ... More
Constraining Lorentz invariance violation using the Crab Pulsar emission observed up to TeV energies by MAGICSep 01 2017Spontaneous breaking of Lorentz symmetry at energies on the order of the Planck energy or lower is predicted by many quantum gravity theories, implying non-trivial dispersion relations for the photon in vacuum. Consequently, gamma-rays of different energies, ... More
MAGIC observations and multiwavelength properties of the quasar 3C279 in 2007 and 2009Jan 13 2011Mar 02 2011Context. 3C 279, the first quasar discovered to emit VHE gamma-rays by the MAGIC telescope in 2006, was reobserved by MAGIC in January 2007 during a major optical flare and from December 2008 to April 2009 following an alert from the Fermi space telescope ... More
MAGIC Upper Limits for two Milagro-detected, Bright Fermi Sources in the Region of SNR G65.1+0.6Jul 20 2010Apr 04 2011We report on the observation of the region around supernova remnant G65.1+0.6 with the stand-alone MAGIC-I telescope. This region hosts the two bright GeV gamma-ray sources 1FGL J1954.3+2836 and 1FGL J1958.6+2845. They are identified as GeV pulsars and ... More
MAGIC TeV Gamma-Ray Observations of Markarian 421 during Multiwavelength Campaigns in 2006Jan 08 2010Aug 03 2010The Major Atmospheric Gamma Imaging Cerenkov (MAGIC) telescope participated in three multiwavelength (MWL) campaigns, observing the blazar Markarian (Mkn) 421 during the nights of 2006 April 28, 29, and 2006 June 14. We analyzed the corresponding MAGIC ... More