Talks

Poster session: the format of the poster is 84cm x 119cm.

Ahlén, Olof
Albert Einstein Institute Potsdam
Germany
A review of Kaluza-Klein reduction I will discuss the process of dimensionally reducing a theory of gravity by compactification on a torus. We will see how a theory of pure gravity gives rise to a lower dimensional theory of gravity with interacting fields. The idea of compactification is central in String Theory and of special importance is compactification on a torus.

Almeida, Luis
Universidade Federal do Acre
Brazil
The sudy of detonation wave in neutron star core L. G. Almeida; H. Rodrigues; S. B. Duarte In this work we present a schematic description of the detonation wave in hadronic matter inside a neutron star core. We have used a simple two shell model where the inner shell medium is initially composed of a small lump of strange quark matter surrounded by an large outer shell composed of hadronic matter. We have utilized an equation of state (EOS) based on Relativistic Mean Field (RMF) with the parameter set NL3 to describe the hot nuclear dense phase. We use the MIT bag model EOS for the description of strange quark matter phase. The Hadron-quark phase transition actually induces explosive modes, which may become a detonation process (faster) or a burning process (slower). The main purpose of the work is to study the formation and the shock propagation front generated by the detonation process and investigate the possibility of mass ejection from the system. The final state could produce a pure quark star or an hybrid remnant star. The masses and radii values obtained for the remnant object in equilibrium are compared with the observational data of pulsars.

Arbañil, José
Technological Institute of Aeronautics
Brazil
Electrically charged strange quark stars: equilibrium and stability Jos\'e D. Arba\~nil and Manuel Malheiro In this work the hydrostatic equilibrium configuration and the stability versus radial perturbation of electrically charged strange quark stars composed by a charged perfect fluid are investigated. We consider that the pressure of the fluid is computed from the MIT bag model equation of state and the charge distribution from a power-law function of the radial coordinate. These studies are possible through the numerical solution of the hydrostatic equilibrium equation, i.e., the Tolman-Oppenheimer-Volkoff (TOV) equation, and the Chandrasekhar's equation pulsation. These both equations are modified of their original versions for the inclusion of the electric charge. We consider only electrical charge values that affects appreciably the star structure, which implies an electric field around $10^{20}[\rm V/cm]$. Compared to the radial pressure, the electrical energy density associated to this electric field is appreciable near the surface of the star. We found that for some range of parameters the electric charge helps to grow the stability of the objects under study. We determine that the zero frequency of oscillation is found in a central energy density larger than the one considered to obtain the maximum mass reached for the charged strange star.

Argüelles, Carlos
ICRANet
Italy
Talk Title: The role of dark matter in astrophysics and particle physics. Authors: C. R. Argüelles, R. Ruffini, N. E. Mavromatos, J. A. Rueda, C. A. Z. Vasconcellos, D. Hajimichef. Abstract: A deep understanding of the role of the dark matter in the different astrophysical scenarios of the local Universe such as galaxies and stars, represent a crucial step to describe in a more consistent way the role of dark matter in cosmology. This kind of studies requires the interconnection between particle physics within and beyond the Standard Model, and fundamental physics such as thermodynamics and statistics, within a fully relativistic treatment of Gravity. In this presentation I discuss the recent efforts made within our group in describing the distribution of dark matter in the center and halo of galaxies from first principles, such as gravitational interactions, quantum statistics and particle physics. Finally, I outline the present and future perspectives regarding the existence of a dark matter candidate within Standard Model extensions and its applications in compact objects such as stars and dark galactic centers, together with the possible decaying emission lines and interactions with the active sector.

Barres de Almeida, Ulisses
Centro Brasileiro de Pesquisas Físicas
Brazil
Cherenkov Telescope Array (CTA) Gamma-ray astronomy holds a great potential for Astrophysics, Particle Physics and Cosmology. The CTA is an international initiative to build the next generation of ground- based gamma-ray observatories, which will represent a factor of 5-10x improvement in the sensitivity of observations in the range 100 GeV - 10 TeV, as well as an extension of the observational capabilities down to energies below 100 GeV and beyond 100 TeV. The arraywill consist of two telescope networks (one in the Northern Hemisphere and another in the South) so to achieve a full-sky coverage, and will be composed by a hybrid system of 4 different telescope types. It will operate as an observatory, granting open access to the community through call for submission of proposals competing for observation time. The CTA will give us access to the non-thermal and high-energy universe at an unprecedented level, and will be one of the main instruments for high-energy astrophysics and astroparticle physics of the next 30 years. CTA has now entered its prototyping phase with the first, stand-alone instruments being built. Brazil is an active member of the CTA consortium, and the project is represented in Latin America also by Argentina, Mexico and Chile. In the next few months the consortium will define the site for installation of CTA South, which might come to be hosted in the Chilean Andes, with important impact for the high-energy community in Latin America. In this talk we will present the basic concepts of the CTA and the detailed project of the observatory. Emphasis will be put on its scientific potential and on the Latin-American involvement in the preparation and construction of the observatory whose first seed, the ASTRI mini-array, is currently being constructed in Sicily, in a cooperation between Italy, Brazil and South Africa. ASTRI should be installed on the final CTA site in 2016, whereas the full CTA array is expected to be operational by the end of the decade.

Barros, Celso
Universidade Federal de Santa Catarina
Brazil
Talk Title: Nuclear Matter in the early Universe Authors: Celso C. Barros Jr. Recently, extreme conditions have been obteined in ultra-relativistic heavy ion collisions at RHIC and at the Large Hadron collider. It is believed that these conditions are similar to the ones of the early Universe, in the time between 10-6s and 1s, approximately. In this talk, the hadron produced in this range of time will be studied, considering some aspects of the systems produced in the heavy ion collisions.

Bartosch Caminha, Gabriel
University of Ferrara
Italy
High precision Strong Lensing Modelling of CLASH-VLT/FF clusters Gabriel Bartosch Caminha, Piero Rosati, Claudio Grillo, Marco Lombardi, and the CLASH-VLT team. In this work we present a detailed mass reconstruction of the CLASH-VLT galaxy cluster RXJ2248. We use a total of 18 strong lensed sources, 11 spectroscopically confirmed by our extensive spectroscopic and imaging data set, of which 3 are new identifications. By using strong lensing techniques we are able to reconstruct the multiple image positions with a offset of ~ 0.5 arcseconds. We also analyse the possibility of probe other quantities with this dataset, such as the background cosmology and the line of sight structure.

Becerra, Laura
La Sapienza University of Rome
Italy
Hypercritical Accretion in Binary Driven Hypernovae: Angular Momentum tranfer

BEGUE, DAMIEN
KTH
Sweden
Title: Poynting flux dominated jets challenged by their photospheric emission Author: D. B\'egu\'e & A. Pe'er Abstract: One of the key open question in the study of jets in general, and jets in gamma-ray bursts (GRBs) in particular, is the magnetization of the outflow. Here we consider the photospheric emission of Poynting flux dominated outflows, when the dynamics is mediated by magnetic reconnection. We show that thermal three-particle processes, responsible for the thermalization of the plasma, become inefficient at a radius $r_{\rm sup} \sim 10^{9.5}$~cm, far below the photosphere, at $\sim 10^{11.5}$~cm. Conservation of the total photon number above $r_{\rm sup}$ combined with Compton scattering below the photosphere enforces kinetic equilibrium between electrons and photons. This, in turn, leads to an increase in the observed photon temperature, which reaches $\gtrsim 8$~MeV (observed energy) when decoupling the plasma at the photosphere. This result is weakly dependent on the free model parameters. We show that in this case, the expected thermal luminosity is a few \% of the total luminosity, and could therefore be detected. The predicted peak energy is more than an order of magnitude higher than the observed peak energy of most GRBs, which puts strong constraints on the magnetization of these outflows.

Belvedere, Riccardo
ICRANet Rio - CBPF
Brazil
ON THE MAGNETIC FIELD OF PULSARS WITH REALISTIC NEUTRON STAR CONFIGURATIONS R. Belvedere, Jorge A. Rueda, R. Ruffini We have recently developed a neutron star model fulfilling global and not local charge neutrality, both in the static and in the uniformly rotating cases. The model is described by the coupled Einstein-Maxwell-Thomas-Fermi equations, in which all fundamental interactions are accounted for in the framework of general relativity and relativistic mean field theory. Uniform rotation is introduced following the Hartle's formalism. We show that the use of realistic parameters of rotating neutron stars, obtained from numerical integration of the self-consistent axisymmetric general relativistic equations of equilibrium, leads to values of the magnetic field and radiation efficiency of pulsars that are very different from estimates based on fiducial parameters that assume a neutron star mass M = 1.4 Msun, radius R = 10 km, and moment of inertia I = 10^45 g cm^2. In addition, we compare and contrast the magnetic field inferred from the traditional Newtonian rotating magnetic dipole model with respect to the one obtained from its general relativistic analog, which takes into due account the effect of the finite size of the source. We apply these considerations to the specific high-magnetic field pulsars class and show that, indeed, all of these sources can be described as canonical pulsars driven by the rotational energy of the neutron star, and have magnetic fields lower than the quantum critical field for any value of the neutron star mass.

Benetti, Micol
National Observatory of Rio de Janeiro
Brazil
Features in the primordial spectrum, constraints from CMB and SDSS data and forecast for the J-PAS experiment. (Micol Benetti, J. Alcaniz, A. Bernui) The recent results from the Planck satellite on the Cosmic Microwave Background (CMB) angular power spectrum shows small but significant features at low multipoles (l~20-60). These features could be explained supporting the Standard Cosmological Model with the inflationary paradigm and assuming a particular class of inflationary models with step-like inflationary potentials. The inflationary potential shape we present is basically a so-called “chaotic potential” type, but here we consider a non constant effective inflaton mass and we parametrize its changes with the introduction of a step function. The variation of the inflaton effective mass produces, in the primordial inflationary potential, a localized oscillation that is able to produce oscillations at large scales in the anisotropy power spectrum of the CMB, improving the fit of the LCDM model. Since it is the same curvature perturbations that set the initial conditions for CMB anisotropies and large-scale structure (LSS) distributions, the primordial oscillatory signals should be imprinted in all the observables of CMB anisotropy and LSS tracers, like CMB spectra, bispectra, galaxy spectra, etc. Therefore, we investigated these models using combined data from the CMB and LSS, since these are independent data able to show the effects of primordial fluctuations at different cosmological scales. Our results shows an improvement of the precision on the step parameters value using both the SDSS survey data and CMB data respect to the same analysis using only CMB data. At the same time, the error bars of the SDSS data on the matter power spectrum are too large to really distinguish the tiny oscillation of the step-like model from the featureless LCDM model. This limit could be resolved by the J-PAS experiment in the next future. J-PAS is a new astronomical facility due to a strict Spanish-Brazilian collaboration. It will be dedicated to mapping the observable Universe in 59 colors and will be able to produce high-quality images and a unique spectral resolution, Our forecast about its data shows a great improvement on the step parameter determination and the c^2 test shows a big preference for the step-like model respect to the LCDM model.

Bernal, Cristian
Instituto de Física, Universidade Federal Fluminense
Brazil
Title: On the magnetic torque of very young pulsars. Author: Cristian G. Bernal Abstract: Rotation Powered-Pulsars are subjected to long-term changes in their period of rotation, which are measured by timing observations of their rotation frequency and its derivatives through the braking index "n". To date, only a handful of such parameter have been estimated for young pulsars, and in all cases one observes that it is less than the expected value for the dipolar oblique rotator (n=3). These observations suggest that there are complex spin-down processes taking place in the pulsar that are not fully well understood. If the pulsar is very young (t < 10 kyr), then it may be exposed to a hyperaccretion phase few moments after the supernova explosion that originated it. Such fallback episode allows the deposit of large amounts of material on the newborn neutron star surface. The magnetic field can then be submerged on the new crust formed during such phase. In the present talk the spin-down of young pulsars, considering a possible magnetic field growth due ohmic diffusion, is revisit. In order to perform such study, numerical simulations and analytical calculations with phenomenological growth functions for the magnetic field were performed. With that it is possible to calculate the spin evolution of the neutron star with all relevant quantities. Such approach could explain the low values of braking index in very young neutron stars and may be relevant to explain why a small group of neutron stars (including central compact objects) exhibit little or no evidence of a standard magnetic field.

Brandt, Carlos
La Sapienza University of Rome
Italy
"VO databases and the BSDC interface", Carlos Brandt and Paolo Giommi

Carneiro da Cunha, Bruno
Universidade Federal de Pernambuco
Brazil
Isomonodromy, Painlevé Transcendents and Scattering of Black Holes We summarise recent developments in obtaining analytical expressions for the scattering coefficients of Kerr and Kerr-de Sitter black holes, using the isomonodrtomy method. These have a lot in common with the theory of Painlevé transcendents and integrable structures, and physically with recent developments in conformal field theories. We are able to derive implicit expressions in terms of Painlevé V and VI tau functions and more amenable analytical expressions in the near-extremal case.

Chardonnet, Pascal
Université de Savoie
France
RENAISSANCE IN ASTROPHYICS : THE PRIMORDIAL STARS The last « Terra incognita » of our Universe is usually called the dark age. It ends with the most powerful fireworks of the universe: the creation of the first stars. With them our Universe change drastically According to theoretical models, massive stars with masses within the 100- 250 solar mass range should explode as pair-instability supernovae (PISNe). Since the first stars of the Universe are believed to be very massive, these supernovae should play a signicant role in the early stages of its history. But these stars represent the last unobserved population, owing to detection limits of current telescopes. In this presentation, we analyze pair-instability supernovae explosions using various numerical codes. We evolve series of the congurations of oxygen cores to establish a range of masses and initial conditions where this type of explosion is possible. I also study the role of possible instabilities in the propagation of shockwaves during the last stage of the explosion. This investigation could help us to predict the observational properties of PISNe for future space and ground telescopes and the possible connections with Gamma-Ray Bursts.

Coelho, Eduardo
Universidade do Estado do Rio de Janeiro (UERJ)
Brazil
Cooling of neutron stars and emissivity of neutrinos by the direct Urca process under influence of strong magnetic field Eduardo Lenho Coelho (UERJ) Marcelo Chiapparini (UERJ) Rodrigo P. Negreiros (UFF) One of the most interesting kind of neutron stars are the pulsars, which are highly magnetized neutron stars with fields up to $10^{14}$ G at the surface. The strength of magnetic field in the center of a neutron star remains unknown. According to the scalar virial theorem, magnetic field in the core could be as large as $10^{18}$ G. Emissivity of neutrinos by the direct Urca process is the mechanism more efficiently of cooling of the neutron stars. It is believed to be the process responsible for the cooling of proto-neutron stars after the first 100 years of life. In this work we study the influence of a magnetic field on the cooling of neutron stars due to the neutrino emissivity by the direct Urca process. The matter is described through a relativistic mean-field model at zero temperature. We calculate numerically the emissivity of neutrinos and the cooling due to the direct Urca process for different magnetic fields.

De Angelis, Alessandro
INFN Padova and IST Lisboa
Italy

de Bernardis, Paolo
Dipartimento di Fisica, Sapienza Università di Roma
Italy
Precision Measurements of the Cosmic Microwave Background P. de Bernardis We review the current status of measurements of the spectrum, anisotropy and polarization of the CMB, and their impact on cosmology. We show that there is still a large discovery potential in these measurements, complementing and synergic to other cosmology observations. We also describe a selection of new measurement efforts, including high precision measurements of CMB polarization with ground-based, stratospheric balloon and satellite experiments, focusing on the astrophysical and technological limits of these mea-surements.

Della Valle, Massimo
Capodimonte Observatory - INAF, Naples
Italy
Supernovae shed light on Gamma-ray Bursts

Duarte, Sergio
CBPF
Brazil
Title: Gravitational wave generated from rapid rotating proto-neutron stars - Authors: H. Rodrigues, A. M. Endler, S. B. Duarte, M. Chiapparini - Abstract: The gravitational wave generated by an isolated newborn neutron star is analyzed, by following the shape evolution of the system during the neutrino cooling phase. The inner core Is modeled as a homogeneous ellipsoid with high angular momentum. Beginning with an axially symmetric configuration the onset of the transition to a triaxial shape is determined by solving the evolutionary path of the axis. It is shown that the transition occurs, generating gravitational wave, when the initial configuration of the core is within a small window of angular momentum and eccentricity. The angular moment and energy carried away by neutrinos and gravitational wave are taken into account in the calculation. Realistic equation of state considering changes in hadronic and leptonic core composition is used, with the leptonic fraction consistently determined by the adopted neutrino escape rate. This equation of state is connected to a Bag model quarkionic equation of state for ultrahigh densities regime. Additionally some aspects of observational interest of the generated gravitational wave are determined.

Enderli, Maxime
La Sapienza Universita' di Roma
Italy
Title: Binary progenitors of GRBs in the fireshell model - Abstract: The classification of gamma-ray bursts based on duration/hardness of the gamma-ray emission involves two classes: long/soft GRBs, thought to originate in collapsar events, and short/hard GRBs, for which circumstantial evidence hints at compact object merger progenitors. Within the fireshell model, theoretical expectations lead to another classification, and each class need not be created by different progenitors. Instead, their divergent properties emerge from various baryon loadings and from the surrounding medium. We highlight the relevance of binary interactions in this framework, in contrast to models involving a single object. All GRBs may be explained by binary progenitors, either through interactions of a FeCO core undergoing a SN explosion with its companion neutron star, or through the merger of compact objects.

Fraga, Bernardo
ICRANet
Italy
Title: A complete sample of Swift/SDSS faint blazars - Abstract: We present a new sample of faint blazars (f x (0.5 - 2keV) > 10^-15 erg cm^-2 s^-1, fr > 1 mJy) serendipitously discovered in deep Swift images centered around 140 Gamma-ray bursts (GRBs). Due to the stacking of the images we obtain exposures ranging from 10 4 to 10 6 seconds. Since GRBs are randomly distributed across the sky our set of deep fields can be considered an unbiased survey of ˜ 12 squares degrees of extragalactic sky with sensitivities reaching 10 -15 erg cm^-2 s^-1 in the 0.5-2.0 keV band. Restricting ourselves to regions where data from SDSS DR10 is available, we find 298 sources. Using this sample we derive general statistical properties and build their Radio and X-ray LogN-LogS.

Giommi, Paolo
ASI Science Data Center, ASDC
Italy
Multi-frequency and multi-messenger astrophysics with Blazars. Recent results and predictions for future observations, including CTA. Paolo Giommi I will discuss some recent multi-frequency and time domain observations of blazars, the most variable type of extragalactic sources and the only kind of AGN capable of emitting radiation across the entire electromagnetic spectrum. Blazars are also the most energetic cosmic accelerators, so particular attention will be given to the X-ray, gamma-ray and VHE energy bands, where the number of blazar expected to be detected in future observations (including CTA) is estimated together with their contribution to the extragalactic backgrounds. Finally, I will describe some recent attempts to open the field of multi-messenger astronomy by comparing the positions of the most energetic blazars with those of extragalactic neutrinos and ultra-high energy cosmic rays.

Gómez Díaz, Luis Gabriel
University of Rome "La Sapienza" and ICRANet
Italy
The impact of Core Density Profiles of Massive Neutrinos "Inos" on Structure formation. L. Gabriel Gómez, Jorge A. Rueda & R. Ruffini. In this talk, We highlight some possible effects of considering Dark Matter Quantum Cores (DMQA) on the one-halo term in the Non-linear Power spectrum. In this way, we may verify the concordance of the model in a cosmological context since, as a first condition, the model itself is capable of reproducing the halo parameters and fitting the rotation curves of galaxies with very good accurate. These DMQA are produced in a self-gravitating system of fermions "Inos" at selected temperatures according to rotation curves of galaxies with two-free parameters values, providing degenerated quantum cores with constant densities.

Gregoris, Daniele
NN
Italy
Application of black hole lattices in relativistic cosmology The talk addresses the open question of providing a theoretical cosmological model accounting for the observed accelerated expansion of the Universe within the framework of General Relativity. An inhomogeneous cosmological modeling of the mass content of the Universe in terms of a family of discrete mass sources (Schwarzschild black hole) is considered. The Einstein equations in vacuum are solved analytically along networks of lines exhibiting local rotationally symmetry. It is shown that the deceleration parameter can be negative without inkoving the existence of any exotic fluid permeating our Universe. The role of the small scale inhomogeneities on the large scale expansion of the Universe is studied in a fully non-perturbative relativistic way thanks to the discrete symmetries of the model.

Guzzo, Marcelo M.
Instituto de Física Gleb Wataghin - UNICAMP
Brazil
Public Talk: Title: Processo URCA na URCA, a energia de uma galáxia numa única estrela Abstract: Focaremos o trabalho do brasileiro Mário Schoenberg com o ucraniano George Gamow sobre o papel dos neutrinos num dos mais espetaculares fenômenos da natureza: o colapso gravitacional de uma estrela, a Supernova. O chamado efeito URCA, proposto por Schoenberg e Gamow, permitiu o entendimento do colapso de modo original e aceito mundialmente até os dias de hoje. Em 1987, neutrinos oriundos de uma Supernova, a SN1987A, foram observados em detectores na Terra pela primeira (e única!) vez.

Hadjimichef, Dimiter
Instituto de Física Universidade Federal do Rio Grande do Sul
Brazil
Talk title:Particle Dark Matter: Astrophysical aspects of milli-charged particles in a Higgs-Stueckelberg model Author: Dimiter Hadjimichef Abstract:An extension of the Standard Model is studied, in which two new vector bosons are introduced, a first boson Z' coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson A' field, in the dark sector of the model, remains massless and originates a dark photon. A hybrid mixing scenario is considered based on a combined Higgs and Stueckelberg mechanisms. In a Compton-like process a photon scattered by a WIMP is converted into a dark photon. This process is studied, in an astrophysical application obtaining an estimate of the impact on stellar cooling of compact stars.

Iocco, Fabio
ICTP-South American Institute for Fundamental Research
Brazil
Title: "Dark Matter in the Milky Way" Author: F. Iocco, M. Pato, G. Bertone Abstract: The presence of dark matter on a wide range of astrophysical scales is one of the observational pillars of the current LambdaCDM cosmological model. In particular, spiral galaxies are known to be dark matter dominated systems, and one of the most outstanding astrophysical proofs of its existence. Yet, retrieving information about the the dark matter distribution in our very own spiral Galaxy, the Milky Way, is quite challenging. This quantity is crucial for both testing the paradigm of the LambdaCDM Universe, and as input for many of the experiments, both ground- and space-based, that are engaged in the search of the very nature of dark matter. In this talk I will present the results of recent analysis that prove evidence of dark matter in the inner region of the Milky Way, a remarkable confirmation of what expected from simulations of Galaxy Formation within the LambdaCDM Universe. I will also show how different analysis of the dataset assembled, permit to derive new and critical information on the dark matter profile of the Milky Way. I will finally comment on the prospects for the future of this field.

Izzo, Luca
Sapienza University of Rome and ICRANet
Italy
Title : Big Data in GRB Astrophysics: two examples from the IGC-GRB-SN scenario and GRB cosmology - Abstract : The current possibility of using a vast amount of GRB data is largely improving our view on GRBs. While in last years we relied on a small, but of the highest quality possible, sample of GRBs for catching their secrets, we still had not enough information on them. Now, with many instruments observing GRBs, in different wavelengths, we can finally analyze many (and messy) data about an astrophysical mystery, as GRB, and clear out the different correlations proposed between GRB observables. We present here two examples, the first one which is directly related with the physics of the progenitor system, and the second one, which has interesting consequences for a possible cosmological use of GRBs, and also for the role of Data Center in GRB astrophysics.

Karlica, Mile
Sapienza University of Rome - ICRANet
Italy
Title: "Synchrotron radiation and diffusive shock acceleration - an GRB afterglow perspective" In this lecture an short introduction to the basic ideas of diffusive shock acceleration and synchrotron radiation mechanism will be given with special interest on later afterglow X-ray emission by GRBs.

Krut, Andreas
ICRANET
Italy
Title: Review of the fermionic model - applied to galactic structures. Galactic structures are assumed to be embedded in an isothermal Dark Matter halo with fermionic behaviour. Only gravitational interaction is considered. Using the Fermi-Dirac distribution it yields an one-parameter family of solutions which reproduces the observed almost flat rotation curve for galaxies. The right scaling is given by the particle mass and the velocity dispersion. For positive central chemical potential the density profile shows three characteristics: an almost uniform very dense core followed by a steep fall, a plateau and a diluted Boltzmannian tail. The core can be described by a velocity cut-off and the tail by the isothermal sphere. The latter is obtained for large negative central chemical potential. The halo follows the law of the so called singular isothermal sphere.

Ludwig, Hendrik
IcraNet
Italy
Title: "Electronic pulsation in giant nuclei" - Abstract: "After motivating the work in the context of neutron star dynamics and gamma ray bursts, I derive the equations that govern the pulsation of electron gas around giant nuclei, present spectrum and stationary modes and give an outlook on how to use these results to investigate the general dynamics of the system using the spectral method."

Malheiro, Manuel
Instituto Tecnológico de Aeronáutica
Brazil
Title: Radio-emission from magnetars and the pulsars of white dwarf - Authors: Ronaldo Vieira Lobato and Manuel Malheiro. Physics Department, Instituto Tecnológico de Aeronáutica São Jo'se dos Campos, São Paulo, Brazil - Abstract: Recently, an alternative model based on white dwarfs pulsars has been proposed to explain a class of pulsars known as Soft Gamma Repeaters (SGR) and Anomalus X-Ray Pulsars (AXP), usually named as magnetars. In this model, the magnetized white dwarfs can have surface magnetic field B ~ 10^7 - 10^10 G and rotate very fast with angular frequencies ~ 1 rad/s, allowing them to produce large electromagnetic (EM) potentials and generate electron-positron pairs. These EM potentials are comparable with the ones of neutron star pulsars with strong magnetic fields and even larger. In this study we consider two possible processes associated with the particle acceleration, both of them are common used to explain radio emission in neutron star pulsars: in the first process the pair production happens near to the star polar caps, i.e. inside of the light cylinder where magnetic field lines are closed; in the second one the creation of pair happens in the outer magnetosphere, i.e. far away of the star surface where magnetic field lines are open. The analysis of the possibility of radio emission were done for 23 SGRs/AXPs of the McGill Online Magnetar Catalog that contains the current information available on these sources. The results of this work show that the model where the particles production occurs in the outer magnetosphere emission "o2" is the one process compatible with the astronomical observations of absence of radio emission for almost all SGRs/AXPs, when these sources are understoond as white dwarf pulsars. We explicitly show that the radius R of these sources modeled as white dwarfs, increases the polar cap radius and the polar cap angle. In the case of SGRs/AXPS that have long periods P ~1 0 s, the light cylinder radius is too large compared to the neutron star radius, but only around 100 times larger than the radius of a dense white dwarf, essentially the same scale of radio neutron star pulsars. This ratio is also important to explain the absense of radio emission in SGRs/AXPs in the outer magnetosphere emission model, where the dipole magnetic field is calculated on the light cylinder radius, much smaller than its value at the star surface. Furthermore, the polar cap model predict radio emission for all sources represented as neutron star pulsars. Our work is a first attempted - using the white dwarf pulsar model - to find an explanation for the puzzle why for almost all the SGRs/XPS were expected radio emission, but it was observed in only four of them.

Marinho, Rubens
Instituto Tecnológico de Aeronautica
Brazil
Title: The importance of RG in the study of WD Authors: Geanderson Araújo Carvalho, Rubens M. Marinho Jr and Manuel M. B. O. Malheiro Abstract: The white dwarfs represent the endpoint of stellar evolution. They are formed when a star with mass between approximately 0.07 to 8-10 $M_\odot$, exhausts its nuclear fuel. At this point the process that sustains its stability stops. After this, the internal pressure can no longer stand the gravitational force and the star collapses. In this work we investigate the structure of these stars which are described by the equations of Tolman-Oppenheimer-Volkoff (TOV) and compare with the Newtonian equations of gravitation in order to put in evidence the importance of the General Relativity i the study of these stars. These equations show us how the pressure varies with the mass and radius of the star. We consider the TOV equations for both relativistic and non-relativistic cases for equation of state (EoS). In the case of white dwarf (WD) star the internal pressure that balances the gravitational one is essentially the pressure coming from the degeneracy of the fermions. To have solved the TOV equations we need an equation of state that shows how this internal pressure is related to the energy density. Instead of using politropic equations of state we have solved the equations numerically using the exact relativistic energy equation for the model of fermion gas at temperature $T=0$ and compared with the solutions using the politropic approaches. We also discuss the instability due to the neutronization threshold and the Coulomb corrections to the Chandrasekhar model for WDs of homogeneous composition that was performed by Hamada and Salpeter (HS) in 1961 and Rotondo, Rueda and Ruffini (RRR) in 2011. We conclude that for a given mass the HS and RRR models give a smaller radius and larger central density compared the Chandrasekhar model. Finally in our results we compute the differences in the maximum mass for WDs composed different nucleus. We also propose a fit of the numerical solution of the TOV with the general EoS for the WD mass-radius diagram. We propose that our fit has to be used as relation between mass and radius for general relativistic WDs instead of that newtonian $M\sim 1/R^3$, this fit is a new expression that we found and is given by $M=(R+a)b/(e^{c(R^2-2)}+d)$, where a, b, c and d are parameters and it can be used in the simulation study of binary systems that occurs accretion. This fit is an approach that covers a large part of the mass-radius relation, i.e., it is valid for most WDs.

Martins de Carvalho, Sheyse
Universidade Federal FLuminense
Brazil
Thermal evolution of neutron stars with global and local neutrality S. M. de Carvalho, R. Negreiros, Jorge A. Rueda, Remo Ruffini Globally neutral neutron stars, obtained from the solution of the called Einstein-Maxwell-Thomas-Fermi equations that account for all the fundamental interactions, have been recently introduced. These configurations have a more general character than the ones obtained with the traditional Tolman-Oppenheimer-Volkoff, which impose the condition of local charge neutrality. The resulting configurations have a less massive and thinner crust, leading to a new mass-radius relation. Signatures of this new structure of the neutron star on the thermal evolution might be a potential test for this theory. We compute the cooling curves by integrating numerically the energy balance and transport equations in general relativity, for globally neutral neutron stars with crusts of different masses and sizes, according to this theory for different core-crust transition interfaces. We compare and contrast our study with known results for local charge neutrality. We found a new behavior for the relaxation time, depending upon the density at the base of the crust, &#961; crust . In particular, we find that the traditional increase of the relaxation time with the crust thickness holds only for configurations whose density of the base of the crust is greater than &#8776; 5 × 10 13 g cm &#8722;3 . The reason for this is that neutron star crusts with very thin or absent inner crust have some neutrino emission process blocked which keep the crust hotter for longer times. Therefore, accurate observations of the thermal relaxation phase of neutron stars might give crucial information on the core-crust transition which may aid us in probing the inner composition/structure of these objects.

Matthiae, Giorgio
Università Roma II and CBPF
Italy
The preliminary proposal for a large ground array for the study of high-energy gamma rays is presented. The Observatory, called LATTES, will be installed in South America at high altitude. The aim is to detect high-energy photons emitted by sources in the Southern Sky. The instrument is complementary to the array HAWC located in the Northern Hemisphere and to the Cherenkov telescopes HESS (CTA).

Menezes, Débora
Universidade Federal de Santa Catarina
Brazil
Quark matter subject to strong magnetic fields: QCD phase diagram and neutron stars Débora Peres Menezes The study of the QCD phase diagram, when matter is subject to intense external magnetic fields has been a topic of intense investigation recently. The fact that magnetic fields can reach intensities of the order of $B \sim 10^{19}$ G or higher in heavy-ion collisions and up to $10^{18}$ G in the center of magnetars made theoretical physicists consider matter subject to magnetic field both at high temperatures and low densities and low temperatures and high densities. In the present work we are interested in understanding various properties of quark matter described by the Nambu-Jona-Lasinio model once it is subject to strong magnetic fields. We start by analysing the possible different phase diagram structures for two parameter sets often used in the literature . Although the general pattern is the same in both cases, the number of intermediate phases is parameter dependent. We then include two different vector interactions, a flavor dependent and a flavor independent NJLv model. We evaluate the differences of pure quark matter obtained with the two models by investigating the behavior of the quark constituent masses and related equations of state in different physical situations (same quark chemical potentials, same quark densities and matter in beta-equilibrium). We have confirmed that at low densities the magnetic field and the vector interaction have opposite competing effects: the first one softens the equation of state while the second hardens it. Once this is understood, we move to quark and hybrid stars subject to an external magnetic field. Having in mind two recently measured massive pulsars, we discuss which form of the vector interaction results in higher compact star masses. Hybrid stars may bare a core containing deconfined quarks if neither the vector interaction nor the magnetic field are too strong.

Muccino, Marco
Dipartimento di Fisica and ICRA, Sapienza Università di Roma
Italy
Title: "GRB 140619B: a genuine short GRB from a binary neutron star merger leading to a black hole " - Authors: M. Muccino, R. Ruffini, C.L. Bianco, M. Enderli, L. Izzo, M. Kovacevic, F.G. Oliveira, A.V. Penacchioni, G.B. Pisani, Y. Wang, E. Zaninoni - Abstract: We give evidence for the existence of a family of “genuine short” GRBs originating from the merging of a binary neutron star (NS) and leading to a black hole (BH) formation. Following the identification of the prototype GRB 090227B, we present here a new example of genuine short burst: GRB 140619B. From the spectral analysis of the early 0.2 s, which is identified with the transparency emission of the e^+e^- plasma, we derive a theoretical redshift z=2.67 and a total burst energy E_tot=(6.03+/-0.79)x10^52 erg. We estimate the corresponding emission of gravitational waves in the binary merging process. The presence of the newly-born BH is evidenced by the observed high energy emission, which is the novel feature of GRB 140619B with respect to the prototype. This emission is consistent with the accretion on a Kerr BH of a fraction of NS–NS crustal masses. We propose also GRB 090510 as a third example of genuine short GRBs. All the three above short GRB fulfill an Ep–E_iso relation with slope \gamma=0.59 and a normalization constant very different from the Amati relation determined from long GRBs.

Nemmen, Rodrigo
Universidade de Sao Paulo
Brazil
Relativistic jets from massive black holes Rodrigo Nemmen (IAG USP) Supermassive black holes in active galactic nuclei (AGN) are key actors in our modern view of the cosmos. How these black holes power extremely energetic, relativistic jets is an outstanding issue. I will review recent observational results which suggest that the central engines in jet-producing AGNs have huge energy-efficiencies, prompting a reassessment of our understanding of jet-production from black holes. I will outline an emerging model for these processes, inspired on general relativistic MHD simulations. I will also present the brazilian participation in the CTA ASTRI mini-array project.

Nœ–ez, Luis
Universidad Industrial de Santander
Colombia
The Latin American Giant Observatory H. Asorey and L.A. Nœ–ez for the LAGO Collaboration In this talk we will describe the LAGO (Latin American Giant Observatory) project: an extended Astroparticle Observatory at global scale, oriented to basic research on three branches of Astroparticle physics: the Extreme Universe, Space Weather phenomena, and Atmospheric Radiation at ground level. The LAGO detection network consists in single or small arrays of low cost particle detectors at ground level, spanning over different sites located at significantly different latitudes (currently from Mexico up to the Antarctic region) and different altitudes (from sea level up to more than 5000 meters over sea level), covering a huge range of geomagnetic rigidity cut-offs and atmospheric absorption/reaction levels. The LAGO Project is operated by the LAGO Collaboration, a non-centralized and distributed collaborative network of more than 80 scientist from more than 25 institutions of 9 latinamerican countries (currently Argentina, Bolivia, Brazil, Colombia, Ecuador, Mexico, Peru and Venezuela. See the complete list of the collaboration members and their institutions).

Oliveira, Fernanda
ICRANet - International Center for Astrophysics Network
Italy
Title: Gravitational Waves Emission using the Effective-one-Body Formalism - Abstract: Merger of neutron star (NS-NS) binaries and neutron star-black hole (NS-BH) binaries are accepted to be the most likely progenitors of short gamma-ray bursts (sGRB) and the contribution of the gravitational waves (GWs) signals produced in the final stage of the coalescence are the most expected signals to be detect by the advanced GW interferometers. We estimate the emission of gravitational waves from adiabatic inpiral phase of NS-NS binaries using the effective-one-body formalism and we estimate the detectability by the Advanced LIGO interferometer computing the signal-to-noise ratio (SNR) using the theoretical cosmological redshift $z=1.61$ and $z=2.67$ for short GRB 090227B and GRB 140619B, respectivally. We find for GRB 090227B that the gravitational waves signal would produce a $\rm \langle SNR\rangle \approx 0.32$ and for GRB 140619B $\rm \langle SNR\rangle \approx 0.21$. The redshift at which Advanced LIGO would detect short GRBs with $ \rm \langle SNR \rangle = 8$ we obtained a value of $z \approx0.05$. In the context of long gamma-ray bursts associated to type Ic supernovae, called binary-driven hypernovae (BdHNe), the induced gravitational collapse (IGC) paradigm has been tested in GRBs with isotropic energies of $E_{iso} \gtrsim 10^{52}$ erg and cosmological redshifts ranging from $z = 0.34$ all the way up to $z = 8.2$. A BdHN lead to new NS-BH binary. We estimate the SNR for the NS-BH binaries product of BDHNe: we obtained a maximum of $SNR = 2.02$ for the closest tested source with $z= 0.34$. The Advanced LIGO could detect GW signals from NS-BH binaries a $z \approx 0.08$ with a $SNR \approx 8$.

Penacchioni, Ana Virginia
INPE
Brazil
Authors: A.V. Penacchioni?, J. Braga, M.A. Castro, F. D'Amico nstituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas, 1758, CEP 12227-010, Sa~o Jose? dos Campos, SP, Brazil - *email: ana.penacchioni@inpe.br - In this work we present the results of imaging simulations performed with the help of the GEANT4 package for the protoMIRAX hard X-ray balloon experiment. The instrumental background was simulated taking into account the various radiation components and their angular dependence, as well as a detailed mass model of the experiment. We modeled the meridian transits of the Crab Nebula and the Galactic Centre region during balloon flights in Brazil (??23? of latitude and an altitude of ?40 km) and introduced the correspondent spectra as inputs to the imaging simulations. We present images of the Crab and of three sources in the Galactic Centre region: 1E 1740.7-2942, GRS 1758-258 and GX 1+4. The results show that the protoMIRAX experiment is capable of making spectral and timing observations of bright hard X-ray sources as well as important imaging demonstrations that will contribute to the design of the MIRAX satellite mission.

Pereira, Jonas Pedro
ICRANet Rio-CBPF
Brazil
Title: Radial stability in stratified stars Abstract: We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the boundary conditions connecting two any phases within a star and underline its relevance for realistic models of compact stars with phase transitions, owing to the modification of the star's set of eigenmodes with respect to the continuous case.

Pisani, Giovanni Battista
Sapienza Università di Roma
Italy
TITLE: Perspectives for binary driven hypernovae at high redshift - ABSTRACT: One of our major recent results is the discovery of a striking common behavior in the late X-ray luminosity light curve within a "golden sample" of nearby, energetic, multiepisodic long GRBs associated with SNe. This result contributed to the development of the new concept of binary-driven hypernova (BdHN). This scaling law has rapidly become a necessary criterium for the BdHN identification, allowing us to predict the SN emergence in the optical band ~ 13 days after the GRB 130427A explosion. We have recently identified the farthest (z = 8.2) GRB 090423 as a BdHN thanks to the overlapping of its X-ray luminosity with the BdHNe ones at late times. This result opens the way for this scaling law to be extended at high redshifts. If confirmed, this would lead to the use of BdHNe as standard candles to test the LambdaCDM model.

Ramos, Ramaton
CBPF
Brazil
Title: The spectra of X-ray binary pulsars extracted from blackbody radiation law in curved spaces and with extra dimensions. Abstract: Many astrophysical objects show X-ray emission which are not satifactorialy explained by the main proposed models. The EXOSAT observations in the 80's and the more recent XMM-Newton observations accumulated data not described by the usual blackbody radiation nor by any existing models in the literature. These models and the blackbody approach are developed in Minkowski background with four dimensions. In the present work we study the change in blackbody radiation due to a flat or curved higher-dimensional spacetime. Our proposal explain the low-energy spectrum of this objects together with its high-energy unaccounted emission as we are considering them a higher-dimensional blackbody spectrum as a whole. Authors: Ramaton R.; S. B. Duarte; H. Boschi-Filho

Rangel Lemos, Luis Juracy
Universidade Federal do Tocantins
Brazil
Title: Applying the luminosity function statistics in the Fireshell model Authos: L. J. Rangel Lemos; C. L. Bianco; R. Ruffini Abstract The luminosity function (LF) statistics applied to the data of BATSE, GBM/Fermi and BAT/Swift is the theme approached in this work. The LF is a strong statistical tool to extract useful information from astrophysical samples, and the key point of this statistical analysis is in the detector sensitivity, where we have performed careful analysis. We applied the tool of the LF statistics to three GRB classes predicted by the Fireshell model. One of the main differences between the Fireshell and Fireball models is the explanation of the GRB prompt emission, where the &#64257;rst claims that it is divided in two physical processes: 1 - transparency of a optically thick &#64257;reshell producing the P-GRB emission and 2 - interaction of a relativistic shell (composed by baryons e&#8722; e+ &#947;) against the CBM (circumburst medium), producing the emission so-called extended afterglow peak (EAP). However, the Fireball model, the most quoted one, claims that the prompt emission is caused by interactions among several relativistic shells (composed by e&#8722; e+ &#947;) with different Lorentz &#947;-factors, a process called internal shocks. The transparency produces a strong short emission in the &#64257;rst few seconds, called P-GRB. Thus, to the Fireshell model, the prompt emission is P-GRB + EAP. We produced, by LF statistics, predicted distributions of: peak &#64258;ux N(Fph pk ), redshift N(z) and peak luminosity N(Lpk) for the three GRB classes predicted by Fireshell model; we also used three GRB rates. We looked for differences among the distributions, and in fact we found. We performed a comparison between the distributions predicted and observed (with and without redshifts), where we had to build a list with 220 GRBs with known redshifts. We also estimated the effects of the Malmquist bias in all samples, and we looked for a correlation between the isotropic luminosity and the Band peak spectral energy.

Romero, Carlos
Departamento de Física / Universidade Federal da Paraíba
Brazil
Title: Einstein and Weyl: on the quest for unification Abstract: Weyl´s attempt to unify electromagnetism and gravity set the stage for a number of developments in theoretical physics and geometry. We review the essential ideas of Weyl's theory and Einstein´s reaction at the time. We revisit some aspects of Weyl geometry and discuss the role they could still play to approach some problems of contemporary cosmological research.

Rueda Hernandez, Jorge Armando
ICRANet
Italy
Title: Realistic configurations of rotating neutron stars in full general relativity and somo astrophysical implications - Abstract: We construct equilibrium configurations of uniformly rotating neutron stars by integrating the Einstein equations in the axially symmetric case for realistic up-to-date nuclear equations of state (EOS). We outline the main properties of the configurations: mass, polar and equatorial radii, eccentricity, angular momentum, moment of inertia, and quadrupole moment, for different values of the central density and angular velocity. The maximum rotation frequency, maximum mass, and limits of stability (mass-shedding and secular instability) are also shown. We find fitting formulas for relevant quantities in astrophysical applications such as the neutron star binding energy as well as the binding energy and angular momentum of the innermost stable circular orbit of test particles around the neutron star. Astrophysical implications are outlined including the analysis of the soft gamma repeaters and anomalous X ray pulsars (magnetars) which show that 50% of the sources of this class of objects are explainable as traditional rotation powered neutron stars.

Ruffini, Remo
ICRANet Pescara, Nice, Rio de Janeiro, Rome, Yerevan
Italy
Titolo: Cosmic Matrix in the Jubilee of Relativistic Astrophysics - Abstract: Following the classical works on Neutron Stars, Black Holes and Cosmology, I outline some recent results obtained in the IRAP-PhD program of ICRANet on the "Cosmic Matrix": a new astrophysical phenomenon recorded by the X- and Gamma-Ray satellites and by the largest ground based optical telescopes all over our planet. In 3 minutes it has been recorded the occurrence of a "Supernova", the "Induced-Gravitational-Collapse" on a Neutron Star binary, the formation of a "Black Hole", and the creation of a "Newly Born Neutron Star".

Sawant, Disha
University of Ferrara
Italy
Title: GRB correlations as a tool for cosmology - Abstract: In order to use GRBs as cosmological tools, we have tried to standardizing them with respect to most exploited and robust correlation, which is E_p,i- intensity correlation. We have also tested the variations of this correlation in terms of different luminosity indicators and studied the variations of each of this correlation on the basis of the scatter and omega_M computations. Also, for understanding the selection effects and instrumental bias, we analyzed the FERMI GRB spectra resolving it in short time intervals. We tried to check the reliability of the correlation from the analysis.

Shellard, Ronald
Centro Brasileiro de Pesquisa Físicas
Brazil
TITLE: Recent results of the Pierre Auger Observatory ABSTRACT: The Pierre Auger Observatory, in the Province of Mendoza, in Argentina is sensitive too cosmic rays with energies greater than 0.1 EeV. In this talk we will report the main results published by Auger in its almost ten years of continuous running.

Siutsou, Ivan
CAPES - ICRANet at CBPF
Brazil
Aksenov A., Siutsou I., Vereshchagin G. On thermalization of electron-positron-photon plasma Abstract: Recently a progress has been made in understanding thermalization mechanism of relativistic plasma. We improve a numerical code used for the study of plasma thermalization. Such code solves relativistic Boltzmann equations for homogeneous isotropic plasma with collision integrals for two- and three-particle interactions calculated from the first principles by means of QED matrix elements. The improvement allows to account for Bose enhancement and Pauli blocking in these interactions. First results, in particular thermalization rates, are presented.

Stahl, Clément
Icranet
Italy
Pair creation in the early Universe - I will discuss in this talk the latest devellopement of fermionic pair creation rate in de Sitter spacetime. To do that I will show the techniques we develloped to solve the Dirac equation in curved spacetime and the explicit derivation of the number of pairs created in the asymptotic future. The result is that the number of fermions is the same as the equivalent problem for boson. Really often in litterature people make the statement that, at high energy, bosons and fermions are the same. Our result is a striking concrete illutration of this statement. Work in collaboration with E. Strobel

Storchi Bergmann, Thaisa
Instituto de Fisica, Universidade Federal do Rio Grande do Sul
Brazil
Supermassive Black Holes and their Role in the Evolution of the Universe Thaisa Storchi Bergmann L'Oreal/UNESCO Prize for Women in Science 2015 From exotic objects predicted by Einstein General Relativity theory, black holes are now considered part of our physical world on the basis of astronomical observations that have become more sophisticated and sensitive over the years. I will present results from observations of the feeding of Supermassive Black Holes - the "monsters" that inhabit the center of galaxies - and the associated feedback effects that influence the evolution of the galaxies and the Universe. ------------------ Buracos Negros Supermassivos e seu Papel da Evolução do Universo Thaisa Storchi Bergmann Prêmio Loreal/UNESCO para mulheres na ciência 2015 Membro da Academia Brasileira de Ciências Membro da TWAS De objetos exóticos preditos pela relatividade geral, os buracos negros passaram à realidade física a partir de observações astronômicas cada vez mais sofisticadas e sensíveis. Apresentarei resultados observacionais sobre a alimentação dos Buracos Negros Supermassivos - os "monstros" que habitam o centro das galáxias - e os efeitos de "feedback" associados que influenciam a evolução das galáxias e do Universo.

Strobel, Eckhard
IcraNet
Italy
Semiclassical pair production rate for rotating electric fields Authors: Eckhard Strobel, She-Sheng Xue We semiclassically investigate Schwinger pair production for pulsed rotating electric fields depending on time. To do so we solve the Dirac equation for two-component fields in a WKB-like approximation. The result shows that for two-component fields the spin distribution of produced pairs is generally not 1&#8758;1. As a result the pair creation rates of spinor and scalar QED are different even for one pair of turning points. For rotating electric fields, the pair creation rate is dominated by particles with a specific spin depending on the sense of rotation for a certain range of pulse lengths and frequencies. We present an analytical solution for the momentum spectrum of the constant rotating field. We find interference effects not only in the momentum spectrum but also in the total particle number of rotating electric fields.

Sversut Arsioli, Bruno
ASDC-ASI & Sapienza University of Rome
Italy
Unveiling Gamma-Ray Blazars - TeV candidates for Cherenkov Telescope Arrays - Blazars are by far the most abundant type of extragalactic gamma-ray sources in the latest Fermi-LAT 3FGL catalog. Still many High Synchrotron Peak blazars have not yet been confirmed as a gamma-ray emitter. Probably most of them are faint gamma-ray sources close or just below the threshold for detectability with Fermi LAT and are not easy to identify by automatic search methods, therefore are currently treated as background. We have performed data reduction with the Fermi Science Tools using the positions from nearly 100 bright High Synchrotron Peaked blazars as seeds of tentative gamma-ray sources. Those gamma-ray candidates were previously selected by multifrequency criteria from radio to X-rays, having the brightest synchrotron peak within the 1WHSP sample (currently the largest sample of HSP blazars). We show that gamma-ray sources in the 0.1-300GeV band can be unveiled taking advantage of multifrequency selection criteria carried out at many orders of magnitude lower energies (from radio to X-rays). Such approach allows to better resolve the gamma-ray sky, and also points to promising candidates for observation with the current and upcoming generation of Cherenkov Telescopes Arrays, like CTA. The Fermi data reduction is currently done in Joshua-cluster from ICRAnet, and we are now implementing the Fermi Science Tools in cooperation with CESUP-Porto Alegre, for performing further work.

Vecchi, Manuela
Instituto de Física de São Carlos - Universidade de São Paulo
Brazil
Title: Precise measurement of the cosmic ray fluxes with the AMS-02 experiment. Abstract: The AMS-02 experiment is a particle detector launched successfully by the NASA American shuttle in May 2011, and installed aboard the International Space Station (ISS) at a 400 km orbit. AMS-02 detects the cosmic rays before they interact in the Earth atmosphere, allowing unprecedented measurements of all cosmic ray components. The AMS-02 detector has been taking data since three years: given its large acceptance, together with excellent background rejection and energy resolution, precision measurements of cosmic ray fluxes have been achieved. In three years of data taking, AMS-02 has collected more than 54 billion cosmic ray events: this is much more than all cosmic rays detected in the past 100 years. This massive amount of precise data will significantly improve our understanding of cosmic ray physics, giving the possibility to constrain theoretical models.In this talk the detector layout will be described, together with the analysis tecnhiques for cosmic ray measurements. The fluxes of cosmic ray positrons, electrons and protons will also be discussed, together with the phenomenological implications of these measurements.

Zaninoni, Elena
ICRANet-Rio @CBPF
Brazil
Ten years of Swift: a universal scaling for short and long gamma-ray bursts (EX,iso-Egamma,iso-Epk) E. Zaninoni, M.G. Bernardini, R. Margutti, L. Amati From the comprehensive statistical analysis of Swift X-ray light-curves collected from the launch of the Swift satellite until the end of 2010, we found a three-parameter correlation between the isotropic energy emitted in the rest frame 1-10^4 keV energy band during the prompt emission (Egamma,iso), the rest frame peak of the prompt emission energy spectrum (Epk), and the X-ray energy emitted in the rest frame 0.3-30 keV observed energy band (EX,iso). The importance of this scaling law is that it is followed by both long and short GRBs, and, at the same time, involves prompt and afterglow emission quantities. Therefore there are some properties which are shared by long and short GRBs as a whole. We updated this correlation considering all GRBs observed until June 2014, confirming the existence of this scaling law, and examining some particular GRBs, as 090426 and 100816A. We also discuss the physics that is driving this correlation.

Zen Vasconcellos, César Augusto
Universidade Federal do Rio Grande do Sul - UFRGS
Brazil
Title: Many-body forces in the equation of state of hyperonic matter Abstract:Rosana de Oliveira Gomes (Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91501-970 Brazil - Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main, Germany), Veronica Dexheimer (Department of Physics, Kent State University, Kent, OH 44242, USA), Stephan Schramm (Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main, Germany) and César A. Zen Vasconcellos (Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 91501-970 Brazil - ICRANet, Piazza della Repubblica 10, 65122 Pescara, Italy) In this work we introduce an extended version of the formalism proposed originally by Taurines et al. that considers the effects of many-body forces simulated by non-linear self-couplings and meson-meson interaction contributions. In this extended version of the model, we assume that matter is at zero temperature, charge neutral, and in beta-equilibrium, considering that the baryon octet interacts by the exchange of scalar-isoscalar (sigma, sigma*), vector-isoscalar (omega, phi), vector-isovector (varrho) and scalar-isovector (delta) meson fields. Using nuclear matter properties, we constrain the parameters of the model that describe the intensity of the indirectly density dependent baryon-meson couplings to a small range of possible values. We then investigate asymmetric hyperonic matter properties. We report that the formalism developed in this work is in agreement with experimental data and also allows for the existence of massive hyperon stars (with more than 2 solar masses, with small radii) compatible with astrophysical observations.