Seminars
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07/07/2011 - 14:00
Coagulation, restructuring and fragmentation of dust grains in the protoplanetary disks: first stages of Solar System formation The understanding of the formation of the planetary systems is one of the main topics of modern astrophysics and its study requires a synergetic effort of observations, laboratory experiments and theoretical models. It is generally accepted that planets originate in the dust disk that remains around a star after its formation (protoplanetary disk). Nevertheless there are no clear ideas on the physical conditions that are required, neither on... Walter Sabolo |
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30/06/2011 - 14:00
Quasi-periodicities in the periodograms of Corot Delta Scuti stars Periodic patterns are not expected to be found in the frequency spectra of delta-Scuti stars, as in solar-like pulsators. However, some efforts have been carried out in order to find any signal of periodicity in this type of stars (Handler et al., 1997; Breger et al., 1999, 2009). These works used ground-base observations and the results have not been conclusive. In our study we have used data from CoRoT of two delta-Scuti stars poorly known. We... Antonio García Hernández |
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20/06/2011 - 14:00
Simulation of Relativistic Jets with Macroscopic and Microscopic Processes and Associated Self-consistent Radiation Relativistic jets are ubiquitous in astrophysical systems. In this talk I will present recent research results from RMHD simulations designed to study the CD kink instability of relativistic jets and the magnetic field amplification that occurs in relativistic shocks in an inhomogeneous medium. I will then present the results of RPIC simulations of particle acceleration in relativistic shocks and self-consistent calculation of the radiation at... Ken Nishikawa |
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16/06/2011 - 14:00
Time-Dependent Hamiltonians in Quantum Mechanics and Inflationary Cosmology We revise the problem which appears in Quantum Mechanics when the Hamiltonian depends explicitly on time and provide a general setting to address such quantum systems. As a paradigmatic example we analyse the case of the damped harmonic oscillator (satisfying the Caldirola-Kanai equation) and extend the system to accomodate the ordinary time translation as a true symmetry (Bateman dual system). This general scheme applies in particular to the... Julio Guerrero García |
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07/06/2011 - 14:00
EST: a large solar telescope for the XXI century The European Solar Telescope (EST) is a project for a 4-meter class telescope to be located in the Canary Islands. It is promoted by the European Association for Solar Telescopes (EAST). This is a consortium formed by a number of research organizations from fifteen European countries (Austria, Croatia, Czech Republic, France, Germany, Hungary, Italy, the Netherlands, Norway, Poland, Slovak Republic, Spain, Sweden, Switzerland, and United... Manolo Collados |
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02/06/2011 - 14:00
Coronal heating on the Sun: new observations and “realistic” 3D numerical models The heating of the solar corona is a long standing problem of solar physics, in fact dating back to the time when it was first discovered that the corona was quite hot. In short, the question is how one can find a credible physical mechanism to transport and dissipate a small fraction of the “mechanical” energy contained in the convection zone in(to) the corona. Amusingly, most answers to the question date back to the late 1940... Prof. Viggo Hansteen |
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31/05/2011 - 14:00
Dark Matter and Stars Under the assumption that Dark Matter (DM) is composed of Weakly Interacting Massive Particles (WIMPs), it can affect the properties of stars. In the local Universe effects are feeble, nonetheless they can in principle be used in order to pose constraints on the nature of DM particles with observations of the Sun, and of compact objects at the Galactic Center, in Globular Clusters and in White Dwarf Galaxies. The first generation of stars to... Fabio Iocco |
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26/05/2011 - 14:00
The BigBOSS dark energy experiment The BigBOSS experiment is a project designed to unlock the mystery of dark energy using existing ground-based facilities operated by National Optical Astronomy Observatory (NOAO). A new 5000-fiber R=5000 spectrograph covering a 3-degree diameter field will measure clustering properties in the distribution of galaxies and hydrogen gas spanning redshifts from 0.2 < z <3.5. This project will enable an unprecedent multi-object spectroscopic... F. Prada & M. Azzaro |
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12/05/2011 - 14:00
ALMA Early Science Tbd Stéphane Léon |
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05/05/2011 - 14:00
Gamma-ray Bursts - what kind of stars do they come from? Long GRBs are the most luminous objects in the universe and mark the collapse of a very massive star, usually accompanied by a relativistic supernova. Their large distances do not allow us to directly identify the progenitor star as we were able to do with some type of supernova. We therefore rely on indirect methods to derive some information on the kind of progenitor star or system and what makes a massive star to explode in a supernova or... Christina Thoene |
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28/04/2011 - 14:00
The connection between missing stellar cusps in galactic nuclei and general relativity One of the most interesting sources of gravitational waves is the inspiral of compact objects on to a massive black hole (MBH), commonly referred to as an extreme-mass ratio inspiral. The small object, typically a stellar black hole, emits significant amounts of GW along each orbit in the detector bandwidth. On the other hand, recent observations of the Galactic center revealed a dearth of giant stars inside the inner parsec relative to the... Pau Amaro Seoane |
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14/04/2011 - 14:00
Discos de acreción alrededor de protoestrellas de masa alta e intermedia Las observaciones directas, que resuelvan angularmente los discos de acreción en torno a estrellas jóvenes de masa alta e intermedia son escasas. Presentaré los resultados de nuevas observaciones radiointerferométricas de alta resolución angular que, junto con nuestros modelos teóricos, revelan la presencia de discos de acreción en torno a dos estrellas en formación. En el caso de la... Mayra Osorio |
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24/03/2011 - 13:00
The dirty side of astronomy: carbonaceous dust Since the beginning of modern astronomy, dust has always been considered an obstacle on the path to understanding both nearby and far away phenomena. In this talk I will explain briefly the origin and the life-cycle of carbonaceous dust, introduce to new discoveries and old puzzles and eventually show how dust can be used as a powerful astronomical tool. Alessandra Candian |
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22/03/2011 - 13:00
Analysis of chemical and dynamical processes in the Earth's Atmosphere with MIPAS data MIPAS is a Fourier transform limb emission mid-infrared spectrometer in Earth orbit. It provides spectrally resolved radiance profiles in the 4.15 to 14.6 mum spectral region from about 5 km up to 70 km (in its nominal mode) and up to 150 km in special observation modes. At IMK and IAA, we retrieve temperature and the distributions of up to 30 trace species from these data, which then are used to study chemistry and dynamics of the atmosphere... Gabi Stiller |
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17/03/2011 - 13:00
Star formation at high-z: a stacking approach applied to mm-data Star formation is a key ingredient of the formation and evolution of galaxies. The associated dust emission has been observed up to very high-z. At mm wavelengths, this can be done thanks to the negative k-correction, which compensates the increasing luminosity distance. However, only the brightest sources can be detected with the present instruments, even with the early ALMA capabilities. Here we present a routine to perform stacking analysis... Roberto Decarli |
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10/03/2011 - 13:00
El Centro Astronómico Hispano-Alemán: 2014-2018 y más allá El Observatorio de Calar Alto cuenta en estos momentos con tres telescopios opticos-infrarrojos y un conjunto de 11 instrumentos que cubren un gran rango de necesidades en distintos campos científicos, con una demanda desigual por parte de la comunidad astronómica. Comenzando con los datos adquiridos durante segundo semestre del 2010, a lo largo del 2011 se procederá a la apertura del archivo público del observatorio, con el objetivo de... David Barrado |
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03/03/2011 - 13:00
A 2D Spectroscopy view of NGC 588 Most of today's stars were formed in high intensity episodes about 7-10 Gyr ago. However, at these redshifts both resolution and dimming effects make it difficult to study in detail the interaction of the gas, dust and newly formed stars. Giant H II regions in very nearby galaxies constitute their best local counterpart to address such a study. Here, I present an analysis of NGC 588, a GHIIR in M33, based on optical Integral Field Spectroscopy... Ana Monreal Ibero |
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24/02/2011 - 13:00
Gravitational Wave Astronomy in the 21st Century The discovery of the binary pulsar PSR B1913+16 by Hulse and Taylor provided definite evidence of the existence of gravitational waves as predicted by Einstein's General Theory of Relativity. It also contributed to encourage the development of different gravitational wave detectors that was pioneered in the 60s by Joseph Weber. Presently, we have a world-wide network of ground detectors that is expected to achieve the first detections during the... Carlos F. Sopuerta |
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17/02/2011 - 13:00
The Physics and Philosophy behind Cosmic Time How far back in time can we have knowledge of the universe? Most cosmologists would agree that the physics describing the ‘material content’ of the universe becomes increasingly speculative the further we go back in time. By contrast, it is widely assumed that the concept of time itself – by virtue of the cosmological standard model – can be safely extrapolated sixty orders of magnitude back from the present to the Planck... Henrik Zinkernagel |
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10/02/2011 - 13:00
A Magnetized Jet from a Massive Protostar Supersonic jets are observed to emerge from a wide variety of astrophysical systems, from young stellar objects (YSOs) to AGNs. Despite their different physical scales (from hundreds to billions of astronomical units), they have strong morphological similarities. However, it is yet unclear whether there is a universal mechanism that can explain the origin of all these jets. Theoretical models suggest that the magnetic field is a fundamental... Carlos Carrasco González |
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03/02/2011 - 13:00
The Transneptunian Region and Clues about Planet Formation The Transneptunian belt is a reservoir of icy bodies in the outer reaches of our solar system. This region is believed to be the source of the Jupiter-Family Comets and is also thought to contain very pristine material, the leftovers of planet formation beyond the ice line. Therefore, the TransNeptunian Objects (TNOs) carry important information on how the solar system was formed, and can give plenty of details on the processes that were... José Luis Ortíz |
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01/02/2011 - 13:00
The ESO VLT instrumentation: Technical overview The present talk emphasizes the most relevant challenges which have been overcome from engineering point of view in order to build the first generation of VLT instruments. Indeed, VLT instrumentation has meant an enormous leap into technical complexity with respect to existing instrumentation for 4m-class telescopes. How ESO has managed the design, procurement and installation of the VLT instrument suite is here presented, as well as the special... Jean-Louis Lizon |
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27/01/2011 - 13:00
Substellar Objects in Nearby Young Clusters (SONYC): Towards an Unbiased Census SONYC, "Substellar Objects in Nearby Young Clusters", is an ongoing project to provide a complete census of the brown dwarf and planemo (free-floating objects with masses comparable to those of massive planets)population in nearby young clusters. The SONYC survey relies on extremely deep wide-field optical and near-infrared imaging and follow-up spectroscopy. We make use of Subaru, VLT, Gemini, CTIO, NTT, and Spitzer to probe the... Koraljka Muzic |
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20/01/2011 - 13:00
Star formation at small galactic scales We present a study of the distribution of star, gas, and dust components in star-forming regions in nearby galaxies. The targets sample a wide range of luminosities and morphologies in order to study how the violent star formation influences the dust and gas distribution inside the star-forming regions. The analysis is based on the comparison of multi-wavelength data from theFar-Ultraviolet (GALEX) to the Infrared (SPITZER and HERSCHEL). Mónica Relaño |
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13/01/2011 - 13:00
Observaciones de la atmósfera de Marte desde la Tierra Hoy día hay un renovado interés en realizar observaciones de Marte con instrumentación en Tierra de un modo sistemático. Y hacerlo, ademas, en el infrarrojo. La tarea no está exenta de dificultades, incluyendo la contaminación telúrica y el pequeño tamaño del planeta rojo. En este seminario resumiré algunas de las investigaciones que se llevan a cabo, en las que participamos, y que están encaminadas a explotar una de las ventanas infrarrojas... Miguel Ángel López Valverde |
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16/12/2010 - 13:00
El campo magnético en galaxias El campo magnético de una galaxia no es solamente importante porque nos proporciona un método de observación, sino también por sus efectos dinámicos. En el pasado se estudió el proceso v -> B pero cada vez se reconoce más el proceso B -> v , es decir el campo magnético ha dejado de ser una magnitud pasiva para influir activamente en el movimiento. La importancia del magnetismo galáctico afecta a determinadas estructuras y también... Eduardo Battaner |
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09/12/2010 - 13:00
Galactic surveys of Planetary nebulae and their astrophysics: past present and future I will briefly review the PN phenomena and describe the power of these objects as probes of stellar evolution and Galactic evolution. I will address their use as potent kinematic tracers and their value as cosmological distance indicators. Finally I will review the recent major progress in discovery, distance determinations and elimination of mimics before touching on the future potential using multi-wavelength optical-MIR-radio data. Quentin Parker |
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02/12/2010 - 13:00
Stellar Population Synthesis at the End of 2010 Recent developments in stellar evolution theory describing critical phases of this process (e.g. TP-AGB), and the availability of new libraries of theoretical and empirical stellar spectra allow us to build more complete and realistic population synthesis models than those in common use. I will discuss the application of these models to various problems of interest and will review those aspects that still require some amount of theoretical and... Gustavo Bruzual |
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23/11/2010 - 13:00
Dark matter on department scale The direct detection of dark matter on Earth depends on its density and its velocity in the Solar neighbourhood. Unforunately, it is uncertain whether the dark matter distribution on the relevant physical scales (milliparsec) is homogeneous or not. Traditional N-body simulations cannot achieve the required resolution, so we have developed an ingenious method, able to achieve virtually any arbitrary resolution at almost no computational cost.... Daniele Fantin |
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18/11/2010 - 13:00
Photometric Redshifts and Cosmology: ALHAMBRA, CLASH and the J-PAS Survey I start with a brief overview of photometric redshifts. I describe the new version of the Bayesian Photometric Redshift software, BPZ, and compare its performance with other public photo-z codes as EAZY or LePhare on datasets like COSMOS or ALHAMBRA. I also introduce two large cosmological projects which heavily rely on photometric redshifts: the MultiCycle Treasury "Clusters and Supernova with Hubble" project, and the Javalambre-PAU... Narciso Benítez |
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11/11/2010 - 13:00
A new sample of faint blazars The available blazar samples were selected at relatively high limiting flux densities in the radio and X-ray band. Those samples have small sizes (30-50 objects) making it difficult to statistically derive parameters related to beaming effects. Moreover, the estimate of those parameters is based on bright and intrinsically luminous sources. A deeper, larger sample of blazars has been constructed by Perlman et al. (1998) and by Landt et al. (2001... Franco Mantovani |
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04/11/2010 - 13:00
Mesospheric CO2 clouds on Mars: observations and study with a General Circulation Model Mesospheric CO2 clouds have been recently observed on Mars, providing important information about the temperatures and winds at the mesosphere, an atmospheric region characterized by the scarcity of observational records. These clouds only appear at particular geographical locations, altitudes above the surface, and times of the year, posing interesting questions about the processes that are at the origin of these clouds. We use a computational... Francisco González Galindo |
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28/10/2010 - 14:00
On the discovery of the Zeeman effect on the Sun and in the laboratory The origin of the discoveries, both on the Sun and in the laboratory, of the action of a magnetic field on spectral lines, the so-called Zeeman effect, is discussed. The talk embraces the period from 1866, the first date of which the speaker is aware of observed evidences about the widening of spectral lines in sunspots (as compared to those formed in the photosphere), until 1908, the year in which the magnetic field in sunspots is definitely... José Carlos del Toro Iniesta |
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21/10/2010 - 14:00
Umbral dots: clues to the internal structure of sunspots Sunspots have been studied since the time of Galileo, but they still remain one of the most active research fields in solar physics. Especially, research on the fine structure of sunspots made great progress with the advent of the Hinode satellite and CRISP spectropolarimetry at the Swedish Solar Telescope on La Palma. Umbral dots (UDs) are tiny bright points observed in the umbra of sunspots. They are scientifically interesting because they... Hiroko Watanabe |
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15/10/2010 - 14:00
The Euler Characteristic as a Measure of the Topology of Cosmic Reionization After giving basic information about what and how we know about the epoch of reionization, I will very briefly introduce the cosmic reionization simulations which I am analyzing. Next, the concepts of topology and, in more detail, the Euler Characteristic are introduced. Only after providing the audience with this necessary background, I will present some results from the analysis of our cosmic reionization simulations. Martina M. Friedrich |
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08/10/2010 - 12:30
El Centro Astronómico Hispano-Alemán: futura instrumentación y operaciones El Observatorio de Calar Alto cuenta en estos momentos con tres telescopios ópticos-infrarrojos y un conjunto de 11 instrumentos que cubren un gran rango de necesidades en distintos campos científicos, con una demanda desigual por parte de la comunidad astronómica. A partir del segundo semestre del 2010 se procederá a la apertura del archivo público del observatorio, optimizando la producción científica. Además, se están desarrollando dos... David Barrado |
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07/10/2010 - 14:00
Características Morfológicas de los Espectros y los Entornos de las Estrellas OB Tbd Nolan Walborn |
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30/09/2010 - 14:00
The Pipe Nebula: Primordial conditions of a quiescent molecular cloud We present the results of a new deep, near-infrared survey of the essentially starless Pipe Nebula, combining data from ESO, Calar Alto, and SPITZER telescopes, and the 2MASS survey. We use this new high sensitivity data set to construct dust extinction maps with spatial resolutions one order of magnitude smaller that the local Jeans Length. Our maps allowed us to determine the structure of the cloud down to and below the scale of dense pre-... Carlos Román Zúñiga |
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16/09/2010 - 14:00
Active Galactic Nuclei at parsec scales We present a representative SED for low-luminosity AGNs, built from high-spatial resolution data for the LINERs and faint Seyferts in the sample. This distribution differs from those of bright Seyferts and Quasars, suggesting that the internal structure of AGNs appears to be largely determined by the amount of energy released by the central engine. On the other hand, we present a multiwavelength study of the nuclear star-formation (~2.5kpc x 2.... Juan Antonio Fernández Ontiveros |
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09/09/2010 - 14:00
GO-IRS: a new multi-object spectrograph for the GTC GO-IRS stands for "GTC Optical Intermediate Resolution Spectrograph". It is the answer of a big team of over 100 experienced researchers and engineers from the University of Florida, China and Spain to the recent call for new instrumentation for the 10.4 m Gran Telescopio Canarias (GTC). The GO-IRS main facts are: 1000 MOS fibres in a 15 arcmin circular field of view; 4x400 IFU fibres in the central 2 arcmin; resolution powers of R=20k... José Antonio Caballero |
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06/09/2010 - 14:00
Fundamental Constants in Time and Space According to the standard model of particle physics, fundamental constants, at least their low-energy limits, should be independent of time and location. Many fundamental constants of physics and astronomy are well defined locally. However, this "constancy of constants'' may not necessarily hold over the largest spatial and temporal scales, which are inaccessible by geological or astronomical studies of nearby targets. Now, advances in... Christian Henkel |
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15/07/2010 - 14:00
The Square Kilometer Array. Should we all wait until 2022? The SKA, composed of several hundreds of 3 different types of antennas with separations up to 3000 km, and up to 200 square degrees FOV, can be considered as the largest, most sensitive, and most difficult radio telescope ever to be built. Some of the research areas where it will be able to provide fundamental answers include the dark era, when gas in galaxies was first turned in stars and the first black holes formed, star formation in nearby... Lourdes Verdes-Montenegro |
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08/07/2010 - 14:00
Escalado de la variabilidad y la luminosidad en rayos X en fuentes ULXs Las fuentes Ultra-luminosas en rayos X (ULXs, del inglés Ultra-luminous X-ray sources) pueden ser la población que conecta los agujeros negros de nuestra Galaxia (<1000 MSol) y los objetos supermasivos en el centro de las galaxias (1E+05-1E+08 MSol). Éstos son los denominados agujeros negros de masas intermedias (1000-100000 MSol). Sin embargo su naturaleza aún no está clara. Recientemente hemos investigado la relación entre la amplitud de la... Omaira González Martín |
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02/07/2010 - 14:00
An Initial Mass Function for Individual Stars in Galactic Disks The Initial Mass Function (IMF) has been derived by a variety of methods. Here we propose an IMF form (a Smoothed Two-Power Law psi_STPL) that approaches a power law at both low stellar masses (psi_STPL ~ m^(gamma)) and at high stellar masses (psi_STPL ~ m^(-Gamma)) with a turnover near the characteristic mass m_ch. The values of gamma and m_ch are derived from two integral constraints: i) the ratio of the number density of stars in the range m=... Antonio Parravano |
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01/07/2010 - 14:00
Magnetic field configuration at the central region of our Galaxy It has been long debated whether the magnetic field configuration at the central region of our Galaxy is toroidal or poloidal. Previous works that have addressed this question were mainly based on radio observations of non-thermal radio filaments, and sub-mm polarimetric observations of dense molecular clouds. I will present a result of a wide-field near-infrared polarimetric survey of the central 2 deg by 2deg region; these wavelengths trace... Shogo Nishiyama |
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17/06/2010 - 14:00
Gamma Rays from the Relativistic Plasma Jets of Blazars X-ray and gamma-ray flares are a common occurrence in blazars, active galactic nuclei with relativistic plasma jets that are pointing almost directly at us. This talk will present the results of a comprehensive multi-waveband monitoring program of blazars with gamma-ray flares observed by the Fermi Gamma-ray Space Telescope. The relative timing of the flares at different wavebands and the emergence of bright radio knots moving down the jet at... Alan P. Marscher |
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27/05/2010 - 14:00
An overview of regional atmospheric phenomena on Mars Tbd Aymeric Spiga |
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20/05/2010 - 14:00
2009 Año Internacional de la Astronomía: un año para recordar Hemos dicho adiós al Año Internacional de la Astronomía (AIA-IYA2009). En España nos propusimos organizar un Año de la Astronomía con un nivel de excelencia acorde con la magnífica evolución que esta rama de la ciencia ha tenido en nuestro país en las últimas décadas y lo hemos conseguido. Las cifras hablan por sí solas: más de 3100 actividades organizadas por al menos 1300 entidades con la participación de miles de personas que han convertido... Montserrat Villar Martín |
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13/05/2010 - 14:00
PLATO: The exoplanetary system explorer I present a general overview of the PLAnetary Transits and Oscillations of stars (PLATO) space mission. PLATO was recently approved by ESA’s Science Programme Committee, together with Euclid and Solar Orbiter missions, to enter the so-called definition phase, i.e. the step required before the final decision is taken (only two missions will be implemented). To be launched in 2018, PLATO is a third generation mission, which will take... Juan Carlos Suárez |
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06/05/2010 - 14:00
The IAA cosmic dust laboratory Dust particles exist in a wide variety of scenarios ranging from the Earth's atmosphere to other planetary and cometary atmospheres in the Solar System, interplanetary medium, reflection nebulae, circumstellar disks, etc. Those dust particles play an important role in the radiative balance of the body under study. Light scattering properties of spherical particles can be easily computed from Lorenz-Mie theory. However, in the majority of the... Olga Muñoz Gómez |