Friday, March 27, 2015



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía

rss_1.0 Clasificación por Disciplina

Nomenclatura Unesco > (21) Astronomía y Astrofísica

Mostrando recursos 41 - 60 de 365

41. Searches for point-like and extended neutrino sources close to the galactic center using the antares neutrino telescope - Adrian Martinez, Silvia; Albert, Andreas; André, Michel
A search for cosmic neutrino sources using six years of data collected by the ANTARES neutrino telescope has been performed. Clusters of muon neutrinos over the expected atmospheric background have been looked for. No clear signal has been found. The most signal-like accumulation of events is located at equatorial coordinates R.A. =-46.°8 and decl. =-64.°9 and corresponds to a 2.2s background fluctuation. In addition, upper limits on the flux normalization of an E -2 muon neutrino energy spectrum have been set for 50 pre-selected astrophysical objects. Finally, motivated by an accumulation of seven events relatively close to the Galactic Center...

42. Dark energy and thermonuclear supernovae - Domínguez, Inmaculada; Bravo Guil, Eduardo; Piersanti, L.; Tornambé, A.; Straniero, O.; Höfflich, P.
Nowadays it is widely accepted that the current Universe is dominated by dark energy and exotic matter, the so called StandardModel of Cosmoloy or _CDM model. All the available data (Thermonuclear Supernovae, Cosmic Microwave Background, Baryon Acoustic Oscillations, Large Scale Structure, etc.) are compatible with a flat Universe made by _70% of dark energy. Up to now observations agree that dark energy may be the vacuum energy (or cosmological constant) although improvements are needed to constrain further its equation of state. In this context, the còsmic destiny of the Universe is no longer linked to its geometry but to the...

43. Simulations of radiative shocks and jet formation in laboratory plasmas - Velarde, Pedro; González, Matthias; Oliva, Eduardo; Kasperczuk, Andrzej; Pisarczyk, Tadeusz; Ullschmied, Jiri; Stehlé, Chantal; Rus, Bedrich; García Senz, Domingo; Bravo Guil, Eduardo; Relaño, Antonio
We present the simulations of two relevant hydrodynamical problems related to astrophysical phenomena performed by three different codes. The numerical results from these codes will be compared in order to test both the numerical method implemented inside them and the influence of the physical phenomena simulated by the codes. Under some conditions laser produced plasmas could be scaled to the typical conditions prevailing in astrophysical plasmas. Therefore, such similarity allows to use existing laser facilities and numerical codes suitable to a laser plasma regime, for studying astrophysical proccesses. The codes are the radiation fluid dynamic 2D ARWEN code and the...

44. Supernovae and dark energy - Domínguez, Inmaculada; Bravo Guil, Eduardo; Piersanti, Luciano; Straniero, Oscar; Tornambé, Amedeo
A decade ago the observations of thermonuclear supernovae at high-redhifts showed that the expansion rate of the Universe is accelerating and since then, the evidence for cosmic acceleration has gotten stronger. This acceleration requires that the Universe is dominated by dark energy, an exotic component characterized by its negative pressure. Nowadays all the available astronomical data (i.e. thermonuclear supernovae, cosmic microwave background, barionic acoustic oscillations, large scale structure, etc.) agree that our Universe is made of about 70% of dark energy, 25% of cold dark matter and only 5% of known, familiar matter. This Universe is geometrically flat, older than previously...

45. A population synthesis study of the luminosity function of hot white dwarfs - Torres Gil, Santiago; García-Berro Montilla, Enrique; Krzesinski, Jurek; Kleinman, Scot J.
Context. We present a coherent and detailed Monte Carlo simulation of the population of hot white dwarfs. We assess the statistical significance of the hot end of the white dwarf luminosity function and the role played by the bolometric corrections of hydrogen-rich white dwarfs at high effective temperatures. Aims. We use the most up-to-date stellar evolutionary models and implement a full description of the observational selection biases to obtain realistic simulations of the observed white dwarf population. Methods. Our theoretical results are compared with the luminosity function of hot white dwarfs obtained from the Sloan Digital Sky Survey (SDSS), for...

46. Observation of SN2011fe with INTEGRAL - I : pre-maximum phase - Isern Vilaboy, Jordi; Jean, Pierre; Bravo Guil, Eduardo; Diehl, Roland; Knödlseder, Jurgen; Domingo, A.; Hirschmann, Alina; Hoeflich, Peter; Lebrun, F.; Renaud, M.; Soldi, Simona; Elias-Rosa, Nancy; Hernanz Carbó, Margarita; Kulebi, Baybar; Zhang, X.; Badenes Montoliu, Carles; Domínguez, Inmaculada; García Senz, Domingo; Jordi, Carme; Lichti, G.; Vedrenne, G.; von Ballmoos, Peter
Context. SN2011fe was detected by the Palomar Transient Factory in M101 on August 24, 2011, a few hours after the explosion. From the early optical spectra it was immediately realized that it was a Type Ia supernova, thus making this event the brightest one discovered in the past twenty years. Aims. The distance of the event offered the rare opportunity of performing a detailed observation with the instruments onboard INTEGRAL to detect the ¿-ray emission expected from the decay chains of 56Ni. The observations were performed in two runs, one before and around the optical maximum, aimed to detect the early...

47. A Super-solar metallicity for the progenitor of Kepler's supernova - Park, Sangwook; Badenes Montoliu, Carles; Mori, Koji; Kaida, Ryohei; Bravo Guil, Eduardo; Schenck, Andrew; Eriksen, Kristoffer A.; Hughes, John P.; Slane, Patrick O.; Burrows, David N.; Lee, Jae-Joon
We have performed deep X-ray observations of the remnant of Kepler's supernova (SN 1604) as a Key Project of the Suzaku Observatory. Our main goal is to detect secondary Fe-peak elements in the supernova (SN) ejecta to gain insights into the Type Ia SN explosion mechanism and the nature of the progenitor. Here, we report our initial results. We made a conclusive detection of X-ray emission lines from highly ionized Mn, Cr, and Ni as well as Fe. The observed Mn-to-Cr line flux ratio is ~0.60, ~30% larger than that measured in Tycho's remnant. We estimate an Mn-to-Cr mass ratio...

48. Experiments on the Ionospheric Models in GNSS - Vinh, La The; Quang, Phuong Xuan; García Rigo, Alberto; Rovira Garcia, Adrià; Ibáñez Segura, Marcos - Deimos
In GNSS, one of the main error sources of the Standard Positioning Service (SPS) is introduced by the ionosphere. Although this error can be cancelled by combining two signals at different frequencies, most of the single - frequency mass - market receivers do not benefit from this cancel l ation. For that reason, a set of parameter s is included in the navigation message in order to compute the ionospheric delay of any observation by the Klobuchar model. The Klobuchar model is a very simple model that is able to remove more than the 50% of the ionospheric delay. Recently, more accurate ionospheric models have been introduced such as Global Ionospheric Map (GIM) or the F ast P recise P oint P ositioning ( F PPP ) ionospheric model. In...

49. Testando as Propriedades Físicas do Modelo Unificado de Galáxias de Núcleo Ativo - Audibert, Anelise

50. A galáxia NGC 7020: estudo de populações estelares e de órbitas especiais na sua barra - Bueno, Felipe Augusto Bianchi

51. Perfis de Densidade de Matéria na Redondeza Solar - Aguiar, Gabriel Corrêa de

52. Algoritmo para extração fotométrica nos dados do ESO-VVV: o aglomerado estelar massivo Pismis 24 - Dias, Rafael Augusto Garcia

53. Determinação do campo magnético de estrelas anãs brancas através do efeito Zeeman quadrático - Wilsmann, Karin Wittmann

54. Caracterização das cordas cósmicas girantes a partir da modelagem pela teoria de gravitação de Brans-Dicke - Silva, Renan Floriano da

55. Classificação Espectral de Anãs Brancas - Ourique, Gustavo

56. Mached Filter na Detecção de Caudas de Maré - Queiroz, Anna Barbara de Andrade

57. Revista Mexicana de Astronomía y Astrofísica : Universidad Nacional Autónoma de México. Instituto de Astronomía

58. Mathematical Methods Applied to the Celestial Mechanics of Artificial Satellites 2013 - Prado, Antonio F. Bertachini A.; Masdemont Soler, Josep; Zanardi, Maria Cecilia; Winter, Silvia Maria Giuliatti; Yokoyama, Tadashi; Gomes, Vivian Martins
Postprint (published version)

59. Lagrange y la primera formulación de la mecánica analítica - Navarro, Luis

60. Solar EUV flux rate estimation during mid and strong flares from the ionospheric electron content response signature in GNSS observations - Hernández Pajares, Manuel; García Rigo, Alberto; Juan Zornoza, José Miguel; Sanz Subirana, Jaume; Monte Moreno, Enrique; Aragón Ángel, María Ángeles
A simple and precise technique to measure the sudden Extreme Ultraviolet (EUV) radiation increase of the Sun, during mid and strong flares, has been formulated and demonstrated for the most active part of the last Solar Cycle. On the one hand, it is based on the short time scale of these events, which allows the validity of a simple global overionization model. And on the other hand on the prompt ionospheric response to the EUV ionization, which signature (in terms of the Global Navigation Satellite Systems -GNSSSolar Flare Activity Indicator, GSFLAI) is accurately measured in real-time from the existing global...

Página de resultados:

Busque un recurso