Results for "P. Dominis Prester"

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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
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
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
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
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
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
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
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
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
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
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 discovery of VHE Emission from the FSRQ PKS 1222+21Jan 24 2011Mar 04 2011Very High Energy (VHE) gamma-ray emission from the flat spectrum radio quasar (FSRQ) PKS 1222+21 (4C 21.35, z=0.432) was detected with the MAGIC Cherenkov telescopes during a short observation (~0.5 hr) performed on 2010 June 17. The MAGIC detection coincides ... More
A Fast Very High Energy $γ$-ray Flare from BL Lacertae during a Period of Multiwavelength activity in June 2015Jan 07 2019The mechanisms producing fast variability of the $\gamma$-ray emission in active galactic nuclei are under debate. The MAGIC telescopes detected a fast very high energy (VHE, E$>100$ GeV) $\gamma$-ray flare from BL Lacertae on 2015 June 15. The flare ... 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
Probing the very-high-energy gamma-ray spectral curvature in the blazar PG 1553+113 with the MAGIC telescopesAug 08 2014Apr 13 2015PG 1553+113 is a very-high-energy (VHE, $E>100\,\mathrm{GeV}$) $\gamma$-ray emitter classified as a BL Lac object. Its redshift is constrained by intergalactic absorption lines in the range $0.4<z<0.58$. The MAGIC telescopes have monitored the source's ... More
MAGIC search for VHE $γ$-ray emission from AE Aquarii in a multiwavelength contextJul 14 2014It has been claimed that the nova-like cataclysmic variable (CV) AE Aquarii (AE Aqr) is a very-high-energy (VHE, $E>$100 GeV) source both on observational and theoretical grounds. We aim to search for VHE gamma-ray emission from AE Aqr during different ... More
MAGIC long-term study of the distant TeV blazar PKS 1424+240 in a multiwavelength contextJan 02 2014Jun 11 2014We present a study of the very high energy (VHE; E > 100 GeV) gamma-ray emission of the blazar PKS 1424+240 observed with the MAGIC telescopes. The primary aim of this paper is the multiwavelength spectral characterization and modeling of this blazar, ... More
Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008Mar 23 2016The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays by MAGIC in spring 2007. Before that the source was little studied in different wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in spring 2008. Along MAGIC, ... More
Detection of persistent VHE gamma-ray emission from PKS 1510-089 by the MAGIC telescopes during low states between 2012 and 2017Jun 14 2018Sep 03 2018PKS 1510-089 is a flat spectrum radio quasar strongly variable in the optical and GeV range. We search for low-state VHE gamma-ray emission from PKS 1510-089. We aim to characterize and model the source in a broad-band context, which would provide a baseline ... More
The detection of the blazar S4 0954+65 at very-high-energy with the MAGIC telescopes during an exceptionally high optical stateJan 12 2018The very-high-energy (VHE, $\gtrsim 100$ GeV) $\gamma$-ray MAGIC observations of the blazar S4 0954+65, were triggered by an exceptionally high flux state of emission in the optical. This blazar has a disputed redshift of z=0.368 or z$\geqslant$0.45 and ... 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
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
Chatterjea type fixed point in Partial $b$-metric spacesFeb 08 2019In this paper, we give and prove two Chatterjea type fixed point theorems on partial $b$-metric space. We propose an extension to the Banach contraction principle on partial $b$-metric space which was already presented by Shukla and also study some related ... More
The extreme HBL behaviour of Markarian 501 during 2012Aug 13 2018Aug 14 2018A multiwavelength campaign was organized to take place between March and July of 2012. Excellent temporal coverage was obtained with more than 25 instruments, including the MAGIC, FACT and VERITAS Cherenkov telescopes, the instruments on board the Swift ... 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
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
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
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
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
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
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
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
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
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
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
OGLE-2005-BLG-153: Microlensing Discovery and Characterization of A Very Low Mass BinarySep 02 2010Apr 25 2012The mass function and statistics of binaries provide important diagnostics of the star formation process. Despite this importance, the mass function at low masses remains poorly known due to observational difficulties caused by the faintness of the objects. ... 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.
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
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
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 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
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
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
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
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
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
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
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
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-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 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-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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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 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
Properties of the massive Thirring model from the XYZ spin chainApr 13 2000We consider here the massive Thirring model regularized with the XYZ spin chain. We numerically calculate the mass ratios of particles which lie in the discrete part of the spectrum and obtain results in accordance with the DHN formula and in disagreement ... More
Two component butterfly hysteresis in Ru1222 ruthenocuprateSep 12 2005We report detailed studies of the ac susceptibility butterfly hysteresis on the Ru1222 ruthenocuprate compounds. Two separate contributions to these hysteresis have been identified and studied. One contribution is ferromagnetic-like and is characterized ... 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
The broad-band properties of the intermediate synchrotron peaked BL Lac S2 0109+22 from radio to VHE gamma raysJul 05 2018The MAGIC telescopes observed S2 0109+22 in 2015 July during its flaring activity in high energy gamma rays observed by Fermi-LAT. We analyse the MAGIC data to characterise the very high energy (VHE) gamma-ray emission of S2 0109+22, which belongs to ... More
Long-term multi-wavelength variability and correlation study of Markarian 421 from 2007 to 2009May 29 2016We study the multi-band variability and correlations of the TeV blazar Mrk 421 on year time scales, which can bring additional insight on the processes responsible for its broadband emission. We observed Mrk 421 in the very high energy (VHE) gamma-ray ... More
Discovery of TeV $γ$-ray emission from the neighbourhood of the supernova remnant G24.7+0.6 by MAGICDec 12 2018SNR G24.7+0.6 is a 9.5 kyrs radio and $\gamma$-ray supernova remnant evolving in a dense medium. In the GeV regime, SNR G24.7+0.6 (3FHL\,J1834.1--0706e/FGES\,J1834.1--0706) shows a hard spectral index ($\Gamma$$\sim$2) up to $200$\,GeV, which makes it ... More
Microlensig Binaries with Candidate Brown Dwarf CompanionsAug 11 2012Oct 03 2012Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation history. In this paper, we present the candidate binaries with brown dwarf companions that ... More
Multi-wavelength characterization of the blazar S5~0716+714 during an unprecedented outburst phaseJul 01 2018The BL Lac object S5~0716+714, a highly variable blazar, underwent an impressive outburst in January 2015 (Phase A), followed by minor activity in February (Phase B). The MAGIC observations were triggered by the optical flux observed in Phase A, corresponding ... More
Microlensing Binaries Discovered through High-Magnification ChannelSep 15 2011Nov 29 2011Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of 8 binary lensing events detected through the channel of high-magnification events during the ... 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
Multiwavelength observations of a VHE gamma-ray flare from PKS 1510-089 in 2015Oct 28 2016Feb 28 2017Context. PKS 1510-089 is one of only a few flat spectrum radio quasars detected in the VHE (very-high-energy, > 100 GeV) gamma-ray band. Aims. We study the broadband spectral and temporal properties of the PKS 1510-089 emission during a high gamma-ray ... More
Constraining Dark Matter lifetime with a deep gamma-ray survey of the Perseus Galaxy Cluster with MAGICJun 28 2018Aug 28 2018Clusters of galaxies are the largest known gravitationally bound structures in the Universe, with masses around $10^{15}\ M_\odot$, most of it in the form of dark matter. The ground-based Imaging Atmospheric Cherenkov Telescope MAGIC made a deep survey ... More
Constraining very-high-energy and optical emission from FRB 121102 with the MAGIC telescopesSep 03 2018Fast radio bursts (FRBs) are bright flashes observed typically at GHz frequencies with millisecond duration, whose origin is likely extragalactic. Their nature remains mysterious, motivating searches for counterparts at other wavelengths. FRB 121102 is ... More
Gamma-ray flaring activity of NGC 1275 in 2016-2017 measured by MAGICJun 05 2018We report on the detection of flaring activity from the Fanaroff-Riley I radio galaxy NGC 1275 in very-high-energy (VHE, E $>$ 100 GeV) gamma rays with the MAGIC telescopes. Observations were performed between 2016 September and 2017 February as part ... More
Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopesJun 26 2014Jul 22 2015The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and ... More
MAGIC observations and multifrequency properties of the Flat Spectrum Radio Quasar 3C 279 in 2011Nov 12 2013Jul 07 2014We study the multifrequency emission and spectral properties of the quasar 3C 279. We observed 3C 279 in very high energy (VHE, E>100GeV) gamma rays, with the MAGIC telescopes during 2011, for the first time in stereoscopic mode. We combine these measurements ... More
Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-raysOct 31 2013Mar 05 2014The radio galaxy NGC 1275, recently identified as a very high energy (VHE, >100 GeV) gamma-ray emitter by MAGIC, is one of the few non-blazar AGN detected in the VHE regime. In order to better understand the origin of the gamma-ray emission and locate ... More
Teraelectronvolt pulsed emission from the Crab pulsar detected by MAGICOct 23 2015Aims: 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
Discovery of very high energy gamma-ray emission from the blazar 1ES 0033+595 by the MAGIC telescopesOct 26 2014The number of known very high energy (VHE) blazars is $\sim\,50$, which is very small in comparison to the number of blazars detected in other frequencies. This situation is a handicap for population studies of blazars, which emit about half of their ... More
Detection of very high energy gamma-ray emission from the gravitationally-lensed blazar QSO B0218+357 with the MAGIC telescopesSep 05 2016Context. QSO B0218+357 is a gravitationally lensed blazar located at a redshift of 0.944. The gravitational lensing splits the emitted radiation into two components, spatially indistinguishable by gamma-ray instruments, but separated by a 10-12 day delay. ... More
MAGIC upper limits on the GRB 090102 afterglowNov 14 2013Indications of a GeV component in the emission from GRBs are known since the EGRET observations during the 1990's and they have been confirmed by the data of the Fermi satellite. These results have, however, shown that our understanding of GRB physics ... More
Rapid and multi-band variability of the TeV-bright active nucleus of the galaxy IC 310May 22 2013Jan 10 2014Context. The radio galaxy IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E>100GeV) with the MAGIC telescopes. Originally classified as a head-tail radio galaxy, ... More