http://hdl.handle.net/2117/1138 Sat, 25 May 2013 22:00:39 GMT 2013-05-25T22:00:39Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19289 Title: White dwarf mergers and the origin of R coronae borealis stars Authors: Lorén Aguilar, Pablo; Longland, Richard Leigh; José Pont, Jordi; García-Berro Montilla, Enrique; Althaus, Leandro G.; Isern-Fontanet, J. Abstract: We present a nucleosynthesis study of the merger of a 0.4 M⊙ helium white dwarf with a 0.8 M⊙ carbon-oxygen white dwarf, coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars. Thu, 16 May 2013 11:56:45 GMT http://hdl.handle.net/2117/19289 2013-05-16T11:56:45Z Lorén Aguilar, Pablo; Longland, Richard Leigh; José Pont, Jordi; García-Berro Montilla, Enrique; Althaus, Leandro G.; Isern-Fontanet, J. no We present a nucleosynthesis study of the merger of a 0.4 M⊙ helium white dwarf with a 0.8 M⊙ carbon-oxygen white dwarf, coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars. http://hdl.handle.net/2117/15372 Title: Computer simulations using implicit Lagrangian hydrodynamics in 3D Authors: Escartín Vigo, José Antonio; García Senz, Domingo; Bravo Guil, Eduardo Abstract: The method known as Smoothed Particle Hydrodynamics (SPH) is an important tool in modern numerical Astrophysics. It has been extensively used to simulate a large number of systems ranging from planets to clusters of galaxies. Nevertheless current applications of the method are restricted to dynamical situations because of the limitations in the time-step imposed by the Courant condition. Here we describe the main features of a new implicit SPH code which is able to handle with several thousand particles and, therefore, it can be used to simulate slowly evolving systems. Mon, 27 Feb 2012 09:24:40 GMT http://hdl.handle.net/2117/15372 2012-02-27T09:24:40Z Escartín Vigo, José Antonio; García Senz, Domingo; Bravo Guil, Eduardo no The method known as Smoothed Particle Hydrodynamics (SPH) is an important tool in modern numerical Astrophysics. It has been extensively used to simulate a large number of systems ranging from planets to clusters of galaxies. Nevertheless current applications of the method are restricted to dynamical situations because of the limitations in the time-step imposed by the Courant condition. Here we describe the main features of a new implicit SPH code which is able to handle with several thousand particles and, therefore, it can be used to simulate slowly evolving systems. http://hdl.handle.net/2117/15331 Title: Population Synthesis of Post-Common Envelope White-Dwarf-Main-Sequence Binaries in the Sloan Digital Sky Survey Authors: Torres Gil, Santiago; Camacho Díaz, Judit; Rebassa-Mansergas, Alberto; Zorotovic, Monica; Schreiber, Mathias R.; García-Berro Montilla, Enrique Thu, 23 Feb 2012 12:50:02 GMT http://hdl.handle.net/2117/15331 2012-02-23T12:50:02Z Torres Gil, Santiago; Camacho Díaz, Judit; Rebassa-Mansergas, Alberto; Zorotovic, Monica; Schreiber, Mathias R.; García-Berro Montilla, Enrique no http://hdl.handle.net/2117/11702 Title: Secondary fe-peak nuclei in the tycho supernova remnant Authors: Badenes Montoliu, Carles; Bravo Guil, Eduardo; Hughes, J.P. Abstract: The Mn to Cr mass ratio in supernova ejecta has recently been proposed as a tracer of Type Ia SN progenitor metallicity. We review the advantages and problems of this observable quantity, and discuss them in the framework of two Galactic supernova remnants: the well known Tycho SNR and W49B, an older object that has been tentatively classified as Type Ia. The fluxes of the Mn and Cr Ka lines in the X-ray spectra of these SNRs observed by the Suzaku and ASCA satellites suggest progenitors of supersolar metallicity for both objects. Tue, 08 Mar 2011 10:11:58 GMT http://hdl.handle.net/2117/11702 2011-03-08T10:11:58Z Badenes Montoliu, Carles; Bravo Guil, Eduardo; Hughes, J.P. no The Mn to Cr mass ratio in supernova ejecta has recently been proposed as a tracer of Type Ia SN progenitor metallicity. We review the advantages and problems of this observable quantity, and discuss them in the framework of two Galactic supernova remnants: the well known Tycho SNR and W49B, an older object that has been tentatively classified as Type Ia. The fluxes of the Mn and Cr Ka lines in the X-ray spectra of these SNRs observed by the Suzaku and ASCA satellites suggest progenitors of supersolar metallicity for both objects. http://hdl.handle.net/2117/11292 Title: Monte Carlo simulations of the binary white dwarf population: a progress report Authors: Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique Mon, 07 Feb 2011 12:25:04 GMT http://hdl.handle.net/2117/11292 2011-02-07T12:25:04Z Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique no http://hdl.handle.net/2117/11281 Title: Monte Carlo simulations of the post-common envelope white dwarf-main sequence binary population Authors: Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique; Zorotovic, Monica; Schreiber, Mathias R. Fri, 04 Feb 2011 14:56:23 GMT http://hdl.handle.net/2117/11281 2011-02-04T14:56:23Z Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique; Zorotovic, Monica; Schreiber, Mathias R. no http://hdl.handle.net/2117/11188 Title: The effects of the Observational Selection Criteria on the post common envelope white dwarf-main sequence binary population Authors: Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique; Zorotovic, Mónica; Schreiber, Mathias R.; Rebassa-Mansergas, Alberto Abstract: We present a detailed Monte Carlo simulator of the Galactic population of binary stars. Preliminary results are presented for the white dwarf-main sequence (WD+MS) binary population resulting from a common envelope (CE) episode. We also study the effects of the observational selection criteria on different color-color diagrams, for different binding energy parameters, l , and common envelope efficiencies, aCE. Finally, we also compare our results with the identified population of white dwarf-main sequence binaries in the SDSS Tue, 25 Jan 2011 10:46:40 GMT http://hdl.handle.net/2117/11188 2011-01-25T10:46:40Z Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique; Zorotovic, Mónica; Schreiber, Mathias R.; Rebassa-Mansergas, Alberto no We present a detailed Monte Carlo simulator of the Galactic population of binary stars. Preliminary results are presented for the white dwarf-main sequence (WD+MS) binary population resulting from a common envelope (CE) episode. We also study the effects of the observational selection criteria on different color-color diagrams, for different binding energy parameters, l , and common envelope efficiencies, aCE. Finally, we also compare our results with the identified population of white dwarf-main sequence binaries in the SDSS http://hdl.handle.net/2117/9309 Title: BAETULO XXI, o de com arribar a Mart des de la secundària Authors: Serrano Porta, Lydia; Ramírez Alcántara, Jorge; Portell Canal, Xavier; Pijuan, Caterina; Monfort Peligero, Lluís; Ayza, Assumpta; Berenguer Sau, Jordi; Carnerero López, Sheila; Crespo Artiaga, Daniel; López Codina, Daniel; López Rubio, Juan; Lorén Aguilar, Pablo; Melo Vera, Maria Jesús Tue, 05 Oct 2010 07:35:52 GMT http://hdl.handle.net/2117/9309 2010-10-05T07:35:52Z Serrano Porta, Lydia; Ramírez Alcántara, Jorge; Portell Canal, Xavier; Pijuan, Caterina; Monfort Peligero, Lluís; Ayza, Assumpta; Berenguer Sau, Jordi; Carnerero López, Sheila; Crespo Artiaga, Daniel; López Codina, Daniel; López Rubio, Juan; Lorén Aguilar, Pablo; Melo Vera, Maria Jesús no http://hdl.handle.net/2117/6987 Title: Optimal Interferometric Maneuvers for Distributed Telescopes Authors: Díaz Aguiló, Marc; Mandy, C; Sáenz Otero, Alvar; Miller, D Abstract: The scientfic community has proposed several missions to expand our knowledge about the universe, its formation and search for distant Earth-like planets. Most of the present space-based observation missions have reached angular resolution limits, therefore the potential benefits concerning angular resolution and intensity that can be reaped from the realization of interferometry within a distributed satellite telescope have led to the proposal of several multi-spacecraft systems. Among these missions synthetic imaging space based interferometers, consisting of multiple telescope apertures flying in controlled formation in order to combine received information from each of the flotilla members are nowadays the subject of interesting research. The objective of synthesizing images with high angular resolution, low ambiguity and high intensity is always a tradeoff with the whole fuel consumption of the mission. As a consequence, this research focuses on the design of interferometric maneuvers and optimal interferometric controllers balancing image performance and energy consumption. The first part of the work presents the optimization and design process of coordinated spiral maneuvers due to their interferometric interest when filling the frequency plane of the observed image. On the other hand, the second part focuses in the resolution of an optimal control problem within the LQ framework, to determine the optimal imaging reconfigurations of a formation flying system. Its objective is to balance the quality of the celestial observation and the fuel usage, which are the key aspects of any spacebased observation mission. This study concerning implementability and performance of interferometric maneuvers will lead towards the enlargement of mission lifetime and flexibility of the system while conserving acceptable quality observations. Tue, 20 Apr 2010 07:52:17 GMT http://hdl.handle.net/2117/6987 2010-04-20T07:52:17Z Díaz Aguiló, Marc; Mandy, C; Sáenz Otero, Alvar; Miller, D no The scientfic community has proposed several missions to expand our knowledge about the universe, its formation and search for distant Earth-like planets. Most of the present space-based observation missions have reached angular resolution limits, therefore the potential benefits concerning angular resolution and intensity that can be reaped from the realization of interferometry within a distributed satellite telescope have led to the proposal of several multi-spacecraft systems. Among these missions synthetic imaging space based interferometers, consisting of multiple telescope apertures flying in controlled formation in order to combine received information from each of the flotilla members are nowadays the subject of interesting research. The objective of synthesizing images with high angular resolution, low ambiguity and high intensity is always a tradeoff with the whole fuel consumption of the mission. As a consequence, this research focuses on the design of interferometric maneuvers and optimal interferometric controllers balancing image performance and energy consumption. The first part of the work presents the optimization and design process of coordinated spiral maneuvers due to their interferometric interest when filling the frequency plane of the observed image. On the other hand, the second part focuses in the resolution of an optimal control problem within the LQ framework, to determine the optimal imaging reconfigurations of a formation flying system. Its objective is to balance the quality of the celestial observation and the fuel usage, which are the key aspects of any spacebased observation mission. This study concerning implementability and performance of interferometric maneuvers will lead towards the enlargement of mission lifetime and flexibility of the system while conserving acceptable quality observations. http://hdl.handle.net/2117/1413 Title: In-flight Diagnostics in LISA Pathfinder Authors: Lobo Gutiérrez, José Alberto; Nofrarías, M.; Ramos Castro, Juan José; Sanjuan, J.; Conchillo, A; Ortega, J.A.; Xirgu, X; Araujo, H.; Boatella, C.; Chmeissani, M.; Grimani, C.; Puigdengoles, C.; Wass, P.; García-Berro Montilla, Enrique; García, S.; Martínez, L.M.; Montero, G. Abstract: LISA PathFinder (LPF) will be flown with the objective to test in space key technologies for LISA. However its sensitivity goals are, for good reason, one order of magnitude less than those which LISA will have to meet, both in drag-free and optical metrology requirements, and in the observation frequency band. While the expected success of LPF will of course be of itself a major step forward to LISA, one might not forget that a further improvement by an order of magnitude in performance will still be needed. Clues for the last leap are to be derived from proper disentanglement of the various sources of noise which contribute to the total noise, as measured in flight during the PathFinder mission. This paper describes the principles, workings and requirements of one of the key tools to serve the above objective: the diagnostics subsystem. This consists in sets of temperature, magnetic field, and particle counter sensors, together with generators of controlled thermal and magnetic perturbations. At least during the commissioning phase, the latter will be used to identify feed-through coefficients between diagnostics sensor readings and associated actual noise contributions. A brief progress report of the current state of development of the diagnostics subsystem will be given as well. Thu, 13 Dec 2007 13:23:21 GMT http://hdl.handle.net/2117/1413 2007-12-13T13:23:21Z Lobo Gutiérrez, José Alberto; Nofrarías, M.; Ramos Castro, Juan José; Sanjuan, J.; Conchillo, A; Ortega, J.A.; Xirgu, X; Araujo, H.; Boatella, C.; Chmeissani, M.; Grimani, C.; Puigdengoles, C.; Wass, P.; García-Berro Montilla, Enrique; García, S.; Martínez, L.M.; Montero, G. no Gravity waves, LISA, LISA Pathfinder, Diagnostics LISA PathFinder (LPF) will be flown with the objective to test in space key technologies for LISA. However its sensitivity goals are, for good reason, one order of magnitude less than those which LISA will have to meet, both in drag-free and optical metrology requirements, and in the observation frequency band. While the expected success of LPF will of course be of itself a major step forward to LISA, one might not forget that a further improvement by an order of magnitude in performance will still be needed. Clues for the last leap are to be derived from proper disentanglement of the various sources of noise which contribute to the total noise, as measured in flight during the PathFinder mission. This paper describes the principles, workings and requirements of one of the key tools to serve the above objective: the diagnostics subsystem. This consists in sets of temperature, magnetic field, and particle counter sensors, together with generators of controlled thermal and magnetic perturbations. At least during the commissioning phase, the latter will be used to identify feed-through coefficients between diagnostics sensor readings and associated actual noise contributions. A brief progress report of the current state of development of the diagnostics subsystem will be given as well. http://hdl.handle.net/2117/1379 Title: The initial–final mass relationship of white dwarfs in common proper motion pairs and open clusters Authors: Catalán, S.; Ribas Vila, Immaculada; Isern Vilaboy, Jordi; García-Berro Montilla, Enrique; Allende Prieto, C. Abstract: We have studied white dwarfs in common proper motion pairs (CPMPs) to improve the semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we re- port new results obtained from spectroscopic observations of both members of several CPMPs composed of a F, G or K type star and a DA white dwarf. Mon, 26 Nov 2007 13:50:28 GMT http://hdl.handle.net/2117/1379 2007-11-26T13:50:28Z Catalán, S.; Ribas Vila, Immaculada; Isern Vilaboy, Jordi; García-Berro Montilla, Enrique; Allende Prieto, C. no White dwarfs, Stars evolution, Stars abundances We have studied white dwarfs in common proper motion pairs (CPMPs) to improve the semi-empirical initial–final mass relationship of white dwarfs. In this contribution, we re- port new results obtained from spectroscopic observations of both members of several CPMPs composed of a F, G or K type star and a DA white dwarf. http://hdl.handle.net/2117/551 Title: Model rocket workshop Authors: Rojas Gregorio, José Ignacio; Villardi de Montlaur, Adeline de; Prats Menéndez, Xavier; García-Berro Montilla, Enrique Fri, 10 Nov 2006 10:30:55 GMT http://hdl.handle.net/2117/551 2006-11-10T10:30:55Z Rojas Gregorio, José Ignacio; Villardi de Montlaur, Adeline de; Prats Menéndez, Xavier; García-Berro Montilla, Enrique no Innovación docente, Proyecto, Cohetes, Aeronáutica, Puzzle