Structure and nature of gamma-ray binaries by means of VLBI observations.

Gamma-ray binaries are extreme systems that produce non-thermal emission from radio to very-high-energy (>TeV) gamma rays, with the energy output in the spectral energy distribution (SED) dominated by the MeV–GeV photons. Their broadband emission is usually modulated by the orbital cycle of the system, which suggests that the physical conditions are also periodic and reproducible. The diversity of systems, together with the reproducibility of the conditions within each system, makes gamma-ray binaries excellent physical laboratories in which high energy particle acceleration, diffusion, absorption, and radiation mechanisms can be explored. Nevertheless, the number of known gamma-ray binaries is still very limited, and only a six binary systems have been classified as gamma-ray binaries. These systems produce outflows of relativistic particles emitting synchrotron radio emission that extend up to several astronomical units, which correspond to projected angular scales of a few milliarcseconds (mas) at typical distances of 2-3 kpc. Very Long Baseline Interferometry (VLBI) provide mas resolution and therefore can be used to directly see this radio outflow. In this thesis we present VLBI observations of five of the six gamma-ray binaries known. We have revealed for the first time the radio structure of two gamma-ray binaries, and found periodic changes in the structure of other two. Based on these results, we have established the basic properties and behaviour of the radio emission of gamma-ray binaries on AU scales, and we have contributed to find characteristics that are common to all of them.

Autor/Doctorant: 

Moldón Vara, Francisco Javier

Directors/Tutors: 

Directors: Marc Ribó i Gomis i Josep Maria Paredes i Poy.

Fitxer Tesis: 

Dia: 

Jueves, 5 Julio, 2012

Lloc: 

Sala de Graus Eduard Fontseré. Planta 1 Física

Tribunal: 

Eduardo Ros Ibarra. Profesor Titular de Universidad. Universitat de València. (President). Valentí Bosch i Ramon.Postdoctoral Researcher (Marie Curie Fellow).Dublin Institute for Advanced Studies. (Secretari). James Carl Alexander Miller-Jones.Curtin University Early Career Research Fellow. International Centre for Radio Astronomy Research - Curtin University, Australia. (Vocal).

Hora: 

11:00

Divulgació: Concurs "SonCube: experimenta a la frontera de l'espai"

concurs soncubePer a alumnes de 1r i 2n de batxillerat.

El Departament d'Astronomia i Meteorologia de la UB i l'Institut d'Estudis Espacials de Catalunya presenten el concurs Soncube per a estudiants de batxillerat.

L'objectiu del concurs és motivar els estudiants a presentar un experiment com a part d'un globus sonda estratosfèric. El grup amb el projecte guanyador participarà en la fabricació del seu experiment i el seu enlairament dins de SonCube II.

Inauguración de ALMA (Atacama Large Millimeter Array), el próximo 13 de marzo,

( 6 de marzo de 2013)

Atacama Large Millimeter/submillimeter Array (ALMA), una asociación internacional de Europa, Norteamérica y Asia del Este en colaboración con la República de Chile, es el mayor proyecto astronómico que existe. ALMA será un solo telescopio de diseño revolucionario, compuesto de 66 antenas de alta precisión ubicado en el Llano de Chajnantor, a 5000 metros de altitud en el norte de Chile.

Data: 

Miércoles, 6 Marzo, 2013

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