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 4:1and 7:2 resonances is performed by means of two techniques that proceed differently from theHamiltonian corresponding to the planar restricted elliptic three-body problem. One technique isbased on the classical Schubart averaging while the other is based on a mapping method in whichthe perturbing part of the Hamiltonian is expanded and the resulting terms are ordered according toa weight function that depends on the powers of eccentricities and the coefficients of the terms. Forthe mapping method the effect of Saturn on the asteroidal evolution is introduced and the degree...
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; Orús Pérez, Raül
In the context of the European Space Agency/European Space Operations Centrefunded Study “GNSS Contribution to Next Generation Global Ionospheric Monitoring,”four ionospheric models based on GNSS data (the Electron Density AssimilativeModel, EDAM; the Ionosphere Monitoring Facility, IONMON v2; the TomographicIonosphere model, TOMION; and the Neustrelitz TEC Models, NTCM) have been runusing a controlled set of input data. Each model output has been tested against differentialslant TEC (dSTEC) truth data for high (May 2002) and low (December 2006) sunspotperiods. Three of the models (EDAM, TOMION, and NTCM) produce dSTEC standarddeviation results that are broadly consistent with each other and with standard deviationspreads...
Star visibility and tracking from the Space Station - Bernacca, Pier Luigi; Facchinetti, Claudia; Fantino, Elena
Purpose of the present study is to provide algorithms for and examples of how to simulate star visibility and tracking by a Telescope attached to the main truss of the International Space Station (ISS).The sky visibility of a Telescope is limited by accommodation constraints on the truss, by obstructions caused by Station’s structural elements along with other payloads, by Sun and Moon’s light and by ram atomic Oxygen. It is also limited by Station’s orbit and attitude. The above limiting agents have been modeled vis-a-vis NASA nominal specifications and knowledge of the ambient environment. These models have been used to...
Absolute determination of the Na-22(rho, gamma)Mg-23 reaction rate in novae - José Pont, Jordi; Caggiano, J. A.; Hutcheon, D. A.; Vockenhuber, C.; Buchmann, L.; Sallaska, A.L.; Wrede, C.; Garcia, A.; Storm,, D. W.; Brown, T. A. D.; Ruiz, C.; Snover, K.A.; Ottewell, D.
Gamma-ray telescopes in orbit around the earth are searching for evidence of the elusive radionuclide 22Na produced in novae. Previously published uncertainties in the dominant destructive reaction, 22Na(p,γ)23Mg, indicated new measurements in the proton energy range of 150 to 300 keV were needed to constrain predictions. We have measured the resonance strengths, energies, and branches directly and absolutely by using protons from the University of Washington accelerator with a specially designed beam line, which included beam rastering and cold vacuum protection of the 22Na implanted targets. The targets, fabricated at TRIUMF-ISAC, displayed minimal degradation over a ∼20 C bombardment as...
Improvement of retrieved FORMOSAT-3/COSMIC electron densities validated by ionospheric sounder measurements at Jicamarca - Aragón Ángel, María Ángeles; Liou, Y.-A.; Lee, C.-C.; Reinisch, B.W.; Hernández Pajares, Manuel; Juan Zornoza, José Miguel; Sanz Subirana, Jaume
Inversion techniques applied to GPS‐LEO radio occultation data allow the retrieval ofaccurate and worldwide‐distributed refractivity profiles, which, in the case of theionosphere, can be converted into electron densities providing information regarding theelectron content distribution in this atmospheric region. In order to guarantee the accuracyof the electron density retrievals, two key points should be taken into account: thehorizontal gradients of the electronic distribution and the topside electron content abovethe LEO orbit. The deployment in April 2006 of the satellite Constellation ObservingSystem for Meteorology Ionosphere and Climate (FORMOSAT‐3/COSMIC), carryingGPS receivers on board, provides valuable radio occultation data with global and almostuniform coverage...
The influence of uncertainties in the O-15(alpha, gamma) Ne-19 reaction rate on models of type I X-Ray bursts - Davids, B.; Cyburt, Richard H.; José Pont, Jordi; Mythili, Subramanian
We present aMonte Carlo calculation of the astrophysical rate of the 15O(α,γ)19Ne reaction based on an evaluation of published experimental data. By considering the likelihood distributions of individual resonance parameters derived from measurements, estimates of upper and lower limits on the reaction rate at the 99.73% confidence level are derived in addition to the recommended, median value. These three reaction rates are used as input for three separate calculations of Type I X-ray bursts (XRBs) using spherically symmetric, hydrodynamic simulations of an accreting neutron star. In this way the influence of the 15O(α,γ)19Ne reaction rate on the peak luminosity, recurrence...
The LISA pathfinder DMU and radiation monitor - Wass, P.; Araujo, H.; Fernandez Sopuerta, Carlos; Sanjuan, J.; Ramos Castro, Juan José; Nofrarias, M.; Mateos, I.; Lloro, I.; Canizares, P.; Chmeissani, M.; Conchillo, A.; Díaz Aguiló, Marc; García-Berro Montilla, Enrique; Gesa, L.; Gibert, Fabien; Grimani, C.
The LISA PathfinderDMU(Data Management Unit) flight model was formallyaccepted by ESA andASDon 11 February 2010, after all hardware and softwaretests had been successfully completed. The diagnostics items are scheduledto be delivered by the end of 2010. In this paper, we review the requirementsand performance of this instrumentation, specially focusing on the RadiationMonitor and the DMU, as well as the status of their programmed use duringmission operations, on which work is ongoing at the time of writing.
Is the metallicity of their host galaxies a good measure of the metallicity of Type Ia supernovae? - Bravo Guil, Eduardo; Badenes Montoliu, Carles
The efficient use of Type Ia supernovae (SNIa) for cosmological studies requires knowledge ofany parameter that can affect their luminosity in either systematic or statistical ways. Observationalsamples of SNIa commonly use the metallicity of the host galaxy, Zhost, as an estimatorof the supernova progenitor metallicity, ZIa, that is one of the primary factors affecting SNIamagnitude. Here, we present a theoretical study of the relationship between ZIa and Zhost. Wefollow the chemical evolution of homogeneous galaxy models together with the evolution ofthe supernova rates in order to evaluate the metallicity distribution function, MDF( Z), i.e.the probability that the logarithm of the...
Search for a diffuse flux of high-energy ¿µ with the ANTARES neutrino telescope - Petrovic, J.; Piattelli, P.; Guillard, G.; Picot-Clemente, N.; Picq, C.; Neff, M.; Hallewell, G.; Palioselitis, D.; Halladjian, G.; Pavalas, G.E.; Heijboer, A.J.; Spurio, M.; Taiuti, M.; Lamare, P.; Stolarczyk, Th.; Larosa, G.; Kopper, C.; Kooijman, P.; Kulikowskiy, V.; Sapienza, P.; Kouchner, A.; Van Haren, H.; Schöck, F.; Bogazzi, C.; Bigongiari, C.; Biagi, S.; Vecchi, M.; Kappes, A.; Bertin, V.; Vannoni, G.; Katz, U.; Bazzotti, M.; Payre, P.; Van Elewyck, V.; Kalantar-Nayestanaki, N.; Basa, S.; Vallage, B.; Kalekin, O.; Baret, B.; De Jong, M.; Auer, R.; Kadler, M.; De Wolf, E.; Popa, V.; Aubert, J.J.; Wijnker, G.; Astraatmadja, T.; Vernin, P.; Bou-Cabo, M.; Hsu, C.C.; Tasca, L.; Höbl, J.; Toscano, S.; Herold, B.; Pradier, T.; Hernández Rey, J.J.; Tamburini, C.; Hello, Y.; Assis Jesus, A.C.; Aguilar, J.A.; Fuda, J.L.; Al Samarai, Imen; Galata, S.; Albert, A.; Gay, P.; André, Michel; Giacomelli, G.; Anghinolfi, M.; Gómez González, J.P.; Anton, G.; Graf, K.; Anvar, S.; Ardid, M.; Rujoiu, M.; Russo, G.V.; Roensch, K.; Rostovtsev, A.; Fritsch, U.; Riccobene, Giorgio; Folger, F.; Richardt, C.; Flaminio, V.; Racca, C.; Fehr, F.; Reed, C.; Salesa, F.; Drouhin, D.; Presani, E.; Eberl, T.; Dornic, D.; Dorosti, Q.; Escoffier, S.; Emanuele, U.; Ernenwein, J.P.; Dekeyser, I.; Donzaud, C.; Deschamps, A.; Cottini, N.; Coyle, Pascal; Curtil, C.; Decowski, M.P.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Charvis, Ph.; Cecchini, S.; Carr, J.; Cârloganu, C.; Carminati, G.; Camarena, F.; Capone, A.; Brunner, J.; Busto, J.; Bouwhuis, M.C.; Brown, A.M.; Naumann, C.; Yepes, H.; Motz, H.; Zaborov, D.; Zornoza, J.D.; Zúñiga, J.; Martinez Mora, J.A.; Mazure, A.; Marcelin, M.; Margiotta, A.; Morganti, M.; Moscoso, L.; Meli, A.; Montarulli, T.; Mangano, S.; Lucarelli, F.; Loucatos, S.; Lefèvre, D.; Shanidze, R.; Lim, G.; Schuller, J.P.; Lo Presti, D.; Spies, A.; Loehner, H.; Simeone, F.; Steijger, J.J.M.; Lahmann, R.
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrinotelescope is presented. A (0.83 × 2π) sr sky was monitored for a total of 334 days of equivalent livetime. The searched signal corresponds to an excess of events, produced by astrophysical sources, over theexpected atmospheric neutrino background. The observed number of events is found compatible with thebackground expectation. Assuming an E−2 flux spectrum, a 90% c.l. upper limit on the diffuse νμ fluxof E2Φ90% = 5.3 × 10−8 GeVcm−2 s−1 sr−1 in the energy range 20 TeV–2.5 PeV is obtained. Other signalmodels with...
Secondary fe-peak nuclei in the tycho supernova remnant - Badenes Montoliu, Carles; Bravo Guil, Eduardo; Hughes, J.P.
The Mn to Cr mass ratio in supernova ejecta has recently been proposed as a tracer of Type Ia SNprogenitor metallicity. We review the advantages and problems of this observable quantity, anddiscuss them in the framework of two Galactic supernova remnants: the well known Tycho SNRand W49B, an older object that has been tentatively classified as Type Ia. The fluxes of the Mnand Cr Ka lines in the X-ray spectra of these SNRs observed by the Suzaku and ASCA satellitessuggest progenitors of supersolar metallicity for both objects.
The Berduc L6 chondrite fall: meteorite characterization, trajectory, and orbital elements - Trigo Rodríguez, Josep Maria; Llorca Piqué, Jordi; Madiedo, J. M.; Tancredi, Gonzalo; Edwards, Wayne; Rubin, Alan E.; Weber, Patrick
Abstract–The fall of the Berduc meteorite took place on April 7, 2008, at 01 h 02 min28 s ± 1 s UTC. A daylight fireball was witnessed by hundreds of people from Argentinaand Uruguay, and also recorded by an infrasound array in Paraguay. From the availabledata, the fireball trajectory and radiant have been reconstructed with moderate accuracy.The modeled trajectory was tested to fit the infrasound and strewn field data. From thecomputed apparent radiant a = 87 ± 2 and d = )11 ± 2 and taking into account arange of plausible initial velocities, we obtained a range of orbital solutions....
The elusive nature of the r-stars - Domínguez, I.; Piersanti, Luciano; Cabezón Gómez, Rubén Martín; Zamora, O.; García Senz, Domingo; Abia, C.; Straniero, Oscar
R stars are carbon stars, less luminous and hotter than the carbon stars evolving along the AGB phase. Thus, their carbon enrichment cannot be a consequence of the third dredge-up, a fact also in agreement with the lack of s-element enhancements in their envelopes. Since their discovery the absence of binaries has lead to the conclusion that a previous merger might play a fundamental role in the observed chemical composition, likely through non-standard mixing at the time of the He-flash. On the other hand numerical simulations, in which the He-flash is artificially located close to the edge of a degenerate...
Estudio del horizonte local - Ros Ferré, Rosa Maria
El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido sepresenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical).
Monte Carlo simulations of the formation channels of SNeIb. PoS(SUPERNOVA)008 - Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique
We present a Monte Carlo simulator of the population of binary stars within the solar neighborhood.We have used the most updated models for stellar evolution, a complete treatment of theRoche lobe over ow episodes, as well as a full implementation of the orbital evolution. Specialemphasis has been placed on processes leading to the formation of binary systems in which oneof the members is a white dwarf. As a preliminary application of our Monte Carlo simulator wehave performed a statistical study of the scenarios leading to type Ib supernovae events within ourGalaxy
The effects of the Observational Selection Criteria on the post common envelope white dwarf-main sequence binary population - Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique; Zorotovic, Mónica; Schreiber, Mathias R.; Rebassa-Mansergas, Alberto
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 populationresulting from a common envelope (CE) episode. We also study the effects of the observationalselection 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 identifiedpopulation of white dwarf-main sequence binaries in the SDSS
Monte Carlo simulations of the binary white dwarf population: a progress report - Camacho Díaz, Judit; Torres Gil, Santiago; García-Berro Montilla, Enrique
We present a detailed Monte Carlo simulator of the population of binary starswithin the solar neighborhood. We have used the most updated models for stellar evolution,a complete treatment of the Roche lobe overflow episodes, as well as a full implementation ofthe orbital evolution. Special emphasis has been placed on processes leading to the formationof binary systems in which one of the members is a white dwarf.