2,857 research outputs found

    Spectral analysis of Markarian 421 and Markarian 501 with HAWC

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    The Hight Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory monitors the gamma-ray sky in the energy range from 100 GeV to 100 TeV and has detected two very high energy (VHE) blazars: Markarian 421 (Mrk 421) and Markarian 501 (Mrk 501) in 1.5 years of observations. In this work, we present the spectral analysis above 1 TeV of both sources using a maximum likelihood method and an artificial neural network as an energy estimator. The main objectives are to constrain the spectral curvature of Mrk 421 and Mrk 501 at \sim5 TeV using the EBL models from Gilmore et al. (2012) and Franceschini et al. (2008).Comment: Presented at the 35th International Cosmic Ray Conference (ICRC2017), Bexco, Busan, Korea. See arXiv:1708.02572 for all HAWC contribution

    Statistical measure of complexity for quantum systems with continuous variables

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    The Fisher-Shannon statistical measure of complexity is analyzed for a continuous manifold of quantum observables. It is probed then than calculating it only in the configuration and momentum spaces will not give a complete description for certain systems. Then a more general measure for the complexity of a quantum system by the integration of the usual Fisher-Shannon measure over all the parameter space is proposed. Finally, these measures are applied to the concrete case of a free particle in a box.Comment: 6 pages, 5 figures. Published versio

    Star formation rates of distant luminous infrared galaxies derived from Halpha and IR luminosities

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    We present a study of the star formation rate (SFR) for a sample of 16 distant galaxies detected by ISOCAM at 15um in the CFRS0300+00 and CFRS1400+52 fields. Their high quality and intermediate resolution VLT/FORS spectra have allowed a proper correction of the Balmer emission lines from the underlying absorption. Extinction estimates using the Hbeta/Hgamma and the Halpha/Hbeta Balmer decrement are in excellent agreement, providing a robust measurement of the instantaneous SFR based on the extinction-corrected Halpha luminosity. Star formation has also been estimated exploiting the correlations between IR luminosity and those at MIR and radio wavelengths. Our study shows that the relationship between the two SFR estimates follow two distinct regimes: (1) for galaxies with SFRIR below ~ 100Msolar/yr, the SFR deduced from Halpha measurements is a good approximation of the global SFR and (2) for galaxies near of ULIRGs regime, corrected Halpha SFR understimated the SFR by a factor of 1.5 to 2. Our analyses suggest that heavily extincted regions completely hidden in optical bands (such as those found in Arp 220) contribute to less than 20% of the global budget of star formation history up to z=1.Comment: (1) GEPI, Obs. Meudon, France ;(2) CEA-Saclay, France ;(3) ESO, Gemany ;(4) IAC, Spain. To appear in A&

    The effect of activity-related meridional flow modulation on the strength of the solar polar magnetic field

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    We studied the effect of the perturbation of the meridional flow in the activity belts detected by local helioseismology on the development and strength of the surface magnetic field at the polar caps. We carried out simulations of synthetic solar cycles with a flux transport model, which follows the cyclic evolution of the surface field determined by flux emergence and advective transport by near-surface flows. In each hemisphere, an axisymmetric band of latitudinal flows converging towards the central latitude of the activity belt was superposed onto the background poleward meridional flow. The overall effect of the flow perturbation is to reduce the latitude separation of the magnetic polarities of a bipolar magnetic region and thus diminish its contribution to the polar field. As a result, the polar field maximum reached around cycle activity minimum is weakened by the presence of the meridional flow perturbation. For a flow perturbation consistent with helioseismic observations, the polar field is reduced by about 18% compared to the case without inflows. If the amplitude of the flow perturbation depends on the cycle strength, its effect on the polar field provides a nonlinearity that could contribute to limiting the amplitude of a Babcock-Leighton type dynamo.Comment: 16 pages, 5 figures, accepted by Ap

    The training of investigative skills and their Trends in Educational Leadership. Methodological Proposal

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    Las dinámicas contemporáneas de la Universidad, condicionan investigaciones sobre los procesos de formación profesional con especial énfasis en la formación de las competencias investigativas en docentes y su empoderamiento como líderes científicos. A estos empeños los académicos e investigadores, prestan sus mejores esfuerzos, tratando de potenciar una universidad pertinente, capaz de empoderar a sus profesionales de la plenitud humana liberadora que requiere la sociedad del siglo XXI. La investigación que se presenta responde a la pregunta ¿Cómo contribuir a la formación de líderes científicos en las universidades? Situando su objetivo en desarrollar los procesos de gestión formativa permanente de profesores investigadores, para así convertirlos en agentes de transformación de los contextos laborales en sus l territorios. A través de métodos y teorías científicas se revela la trascendencia de los procesos formativos de investigadores docentes y su valor para la potenciación de los procesos científicos en la comunidad universitaria. Desarrollándose una metodología de intervención para la Universidad UNIANDES, que propicia el surgimiento de líderes investigativosThe contemporary dynamics of the University, condition research on the processes of professional training with special emphasis on the training of research competencies in teachers and their empowerment as scientific leaders. To these efforts academics and researchers, they give their best efforts, trying to promote a relevant university, capable of empowering their professionals to the liberating human fullness that society of the 21st century requires. The research that is presented responds to the question How to contribute to the formation of scientific leaders in the universities? Setting its objective in developing the processes of permanent formative management of research professors, so as to transform them into agents of transformation of labor contexts in their territories. Through scientific methods and theories the transcendence of the educational processes of educational researchers and their value for the enhancement of the scientific processes in the university community is revealed. Developing an intervention methodology for UNIANDES University, which promotes the emergence of investigative leader
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