Biblioteca.Net

1. Local behaviour of evaporating stars and black holes around the total evaporation event - Fayos Vallés, Francisco; Torres Herrera, Ramon

2. Anímate a participar en "Ciencia en Acción" y "Adopta una Estrella" - Ros Ferré, Rosa Maria

3. Un objetivo importante:la astronomía en preescolar y primaria - Ros Ferré, Rosa Maria

4. Neutron capture cross section measurements at n_TOF of 237Np, 240Pu, 243Am, for the transmutation of nuclear waste - Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Poch Parés, Agustí; Pretel Sánchez, Carme
Accurate and reliable neutron capture cross section data for actinides are necessary forthe proper design, safety regulation and precise performance assessment of transmutation devicessuch as Fast Critical Reactors or Accelerator Driven Systems. In particular, the neutron capture crosssections of 237Np, 240Pu and 243Am play a key role in the design and optimization of strategiesfor the Transmutation of Nuclear Waste. The listed cross sections have been measured in 2004at n_TOF [1] with a high accuracy due to a combination of features unique in the world: highinstantaneous neutron fluence and excellent energy resolution of the n_TOF facility, innovative DataAcquisition System based on...

5. Testing the initial-final mass relationship of white dwarfs - Catalán Ruiz, Silvia; Isern Vilaboy, Jordi; García-Berro Montilla, Enrique; Ribas Canudas, Ignasi
In this contribution we revisit the initial-final mass relationship of white dwarfs,which links the mass of a white dwarf with that of its progenitor in the main-sequence. Althoughthis function is of paramount importance to several fields in modern astrophysics, it is still notwell constrained either from the theoretical or the observational points of view. We present herea revision of the present semi-empirical initial-final mass relationship using all the availabledata and including our recent results obtained from studying white dwarfs in common propermotion pairs. We have also analyzed the results obtained so far to provide some clues on thedependence of this...

6. The gravitational wave emission from white dwarf interactions in globular clusters - Lorén Aguilar, Pablo; Lobo Gutiérrez, José Alberto; Isern Vilaboy, Jordi; García-Berro Montilla, Enrique
In the dense central regions of globular clusters close encounters of two white dwarfsare relatively frequent. The estimated frequency is one or more strong encounters per star in thelifetime of the cluster. Such encounters should be then potential sources of gravitational waveradiation. Thus, it is foreseeable that these collisions could be either individually detected byLISA or they could contribute significantly to the background noise of the detector. We computethe pattern of gravitational wave emission from these encounters for a sufficiently broad rangeof system parameters, namely the masses, the relative velocities and the distances of the twowhite dwarfs involved in the...

7. Analysis of extreme rainfall in Barcelona using a microscale rain gauge network - Casas Castillo, M. del Carmen; Rodríguez Solá, Raúl
Extreme storms registered by the urban rain gauge network installed and supported by CLABSA(Clavegueram de Barcelona S. A.) in Barcelona in the period 1994–2001 have been investigated. Eleven rain eventspresenting intensities for durations between 5 min and 24 h with return periods equal to or larger than 5 years for anyof the network gauges have been found. A cluster analysis has yielded four main classes of extreme rainfall events inthis area, related to the meteorological scales involved: local (18%), mesoscale (37%) and synoptic storms (27%), as wellas more complex rain events originated by multiscale mechanisms acting together (18%). An intensity...

8. Algorithm specification for the Magnetic Diagnostics onboard LPF - Díaz Aguiló, Marc; García-Berro Montilla, Enrique; Lobo, Alberto
Document tècnic per la missió espacial LISA Pathfinder. Missió espacial de l'Agència Espacial Europea (ESA).

9. Neural Network algorithms for magnetic diagnostics in the LTP - Díaz Aguiló, Marc; García-Berro Montilla, Enrique; Lobo, Alberto
Document tècnic per la missió espacial LISA Pathfinder. Missió espacial de l'Agència Espacial Europea (ESA).

10. Magnetic experiments on board the LTP - Díaz Aguiló, Marc; García-Berro Montilla, Enrique; Lobo, Alberto
Document tècnic per la missió espacial LISA Pathfinder. Missió espacial de l'Agència Espacial Europea (ESA).

11. LTP Magnetic Field Interpolation - Díaz Aguiló, Marc; García-Berro Montilla, Enrique; Lobo, Alberto
Document tècnic per la missió espacial LISA Pathfinder. Missió espacial de l'Agència Espacial Europea (ESA).

12. Optimal Interferometric Maneuvers for Distributed Telescopes - Díaz Aguiló, Marc; Mandy, C; Sáenz Otero, Alvar; Miller, D
The scientfic community has proposed several missions to expand our knowledge about the universe, its formationand search for distant Earth-like planets. Most of the present space-based observation missions have reached angularresolution limits, therefore the potential benefits concerning angular resolution and intensity that can be reaped from therealization of interferometry within a distributed satellite telescope have led to the proposal of several multi-spacecraftsystems. Among these missions synthetic imaging space based interferometers, consisting of multiple telescope aperturesflying in controlled formation in order to combine received information from each of the flotilla members arenowadays the subject of interesting research. The objective of synthesizing...

13. Population Synthesis of Post-Common Envelope White-Dwarf-Main-Sequence Binaries in the Sloan Digital Sky Survey - Torres Gil, Santiago; Camacho Díaz, Judit; Rebassa-Mansergas, Alberto; Zorotovic, Monica; Schreiber, Mathias R.; García-Berro Montilla, Enrique

14. The upper mass limit for the formation of TP-SAGB stars and the dredge-out phenomenon - Gil Pons, Pilar; Doherty, Carolyn L.
We have computed the evolution of Super-AGB stars from the main sequenceand up to a few hundred thermal pulses, with special attention to the low metallicity cases(Z = 10 10; 10 5; 10 4 and 10 3). Our computations have been performed using time–dependent mixing and new opacity tables that admit variations in the abundances of carbonand oxygen. By following the evolution along the main central burning stages and theearly TP-SAGB, we resolve the upper mass limits for the formation of TP-SAGB stars anddetermine the mass range at which the dredge-out phenomenon occurs. This phenomenoninvolves the merger of a convective...

15. The white dwarf cooling sequence of NGC 6791: an unique tool for stellar astrophysics - García-Berro Montilla, Enrique; Torres Gil, Santiago; Renedo Rouco, Isabel; Camacho Díaz, Judit; Althaus, Leandro Gabriel; Córsico, Alejandro H.; Salaris, Maurizio; Isern Vilaboy, Jordi
Context. NGC 6791 is a well-studied, metal-rich open cluster that is so close to us that it can be imaged down to luminosities fainterthan that of the termination of its white-dwarf cooling sequence, thus allowing for an in-depth study of its white dwarf population.Aims. White dwarfs carry important information about the history of the cluster. We use observations of the white-dwarf coolingsequence to constrain important properties of the cluster stellar population, such as the existence of a putative population of massivehelium-core white dwarfs, and the properties of a large population of unresolved binary white dwarfs. We also investigate the use...

16. Un planeta con dos soles. ¿Tatooine o Kepler-16b? - Moreno Lupiáñez, Manuel
La existencia de un mundo con atardeceres dobles, similar al que se mostró en la película "Star Wars" hace más de 30 años, ya es un hecho científico. La misión Kepler, de la Nasa, ha logrado la primera detección directa de un planeta circumbinario (que orbita alrededor de dos estrellas a la vez) a 200 años luz de distancia de la Tierra.

17. Estimating the rate and luminosity function of all classes of GRBs - Balastegui Manso, Andreu; Canal, Ramon; Ruiz-Lapuente, Pilar
The aim of the present work is to estimate the rate and luminosity functions of short, intermediate and long gamma-ray bursts (GRBs) by fitting their intensity distributions wih parameterized explosion rates and luminosity functions. The results show that the parameters of the rate and luminosity function for long GRBs can be calculated with an accuracy of 10-30%. However, some parameters of intermediate and short GRBs have large uncertainties. An important conclusion is that there was initially a large outburst in the frequency of long GRBs, and consequently a large outburst in the star-formation rate, if they come from collapsars. Finally,...

18. Estimating the rate and luminosity function of all classes of GRBs - Balastegui Manso, Andreu; Canal, Ramon; Ruiz-Lapuente, Pilar
The aim of the present work is to estimate the rate and luminosity functions of short, intermediate and long gamma-ray bursts (GRBs) by fitting their intensity distributions wih parameterized explosion rates and luminosity functions. The results show that the parameters of the rate and luminosity function for long GRBs can be calculated with an accuracy of 10-30%. However, some parameters of intermediate and short GRBs have large uncertainties. An important conclusion is that there was initially a large outburst in the frequency of long GRBs, and consequently a large outburst in the star-formation rate, if they come from collapsars. Finally,...

19. Dynamical behavior of asteroids near resonance: the 4:1 gap and the 7:2 group - Grau Sánchez, Miguel; González Casado, Guillermo
A comparative study of the evolution of the Sun–Jupiter–Asteroid system near the 4:1 and 7:2 resonances is performed by means of two techniques that proceed differently from the Hamiltonian corresponding to the planar restricted elliptic three-body problem. One technique is based on the classical Schubart averaging while the other is based on a mapping method in which the perturbing part of the Hamiltonian is expanded and the resulting terms are ordered according to a weight function that depends on the powers of eccentricities and the coefficients of the terms. For the mapping method the effect of Saturn on the asteroidal evolution is introduced and the degree...

20. Comparative testing of four ionospheric models driven with GPS measurements - Zandbergen, R.; Feltens, Joachim; Angling, M; Jackson Booth, N; Jakowski, Norbert; Hoque, Mainul; Hernández Pajares, Manuel; Aragón Ángel, María Ángeles; Orus, R.
In the context of the European Space Agency/European Space Operations Centre funded Study “GNSS Contribution to Next Generation Global Ionospheric Monitoring,” four ionospheric models based on GNSS data (the Electron Density Assimilative Model, EDAM; the Ionosphere Monitoring Facility, IONMON v2; the Tomographic Ionosphere model, TOMION; and the Neustrelitz TEC Models, NTCM) have been run using a controlled set of input data. Each model output has been tested against differential slant TEC (dSTEC) truth data for high (May 2002) and low (December 2006) sunspot periods. Three of the models (EDAM, TOMION, and NTCM) produce dSTEC standard deviation results that are broadly consistent with each other and with standard deviation spreads...

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