Publications

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    J. M. Rueda-Becerril, P. Mimica, M. A. Aloy
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    ABSTRACT: We explore the signature imprinted by dynamically relevant magnetic fields on the spectral energy distribution (SED) of blazars. It is assumed that the emission from these sources originates from the collision of ultrarelativistic and magnetized shells of cold plasma. A suitable analytic modeling, based on the numerical solution of Riemann problems, accounts for the magnetohydrodynamic evolution of the shell collisions. Using this dynamics we compute model SEDs including the most relevant radiative processes (synchrotron emission, synchrotron self-Compton and external inverse Compton scattering). To quantify the way in which the degree of magnetization shapes the SED, we scan a broad parameter space that encompasses a significant fraction of the commonly accepted values of not directly measurable physical properties. Starting from unmagnetized shell collisions, we reproduce the standard double hump SED found in blazar observations. We also show that the prototype double hump structure of blazars can also be reproduced if the dynamical source of the radiation field is very ultrarelativistic both, in a kinematically sense (namely, if it has Lorentz factors $\gtrsim 50$) and regarding its magnetization (e.g., with flow magnetizations $\sigma \simeq 0.1$). We find that a fair fraction of the {\em blazar sequence} could be explained in terms of the intrinsically different magnetization of the colliding shells: negligible magnetic fields might be present in FSRQs, while more moderate or large (and uniform) magnetization could explain the observed properties of BL Lacs. Our models, due to the approximated treatment of the Klein-Nishina cutoff, predict photon spectral indices ($\Gamma_{\rm ph}$) in the $\gamma-$ray band above the observed values if the magnetization of the sources is moderate ($\sigma\simeq 10^{-2}$).
    Monthly Notices of the Royal Astronomical Society 10/2013; · 5.52 Impact Factor
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    Jesus M. Rueda-Becerril, Petar Mimica, Miguel A. Aloy, Carmen Aloy
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    ABSTRACT: The internal-shocks scenario in relativistic jets has been used to explain the variability of blazars' outflow emission. Recent simulations have shown that the magnetic field alters the dynamics of these shocks producing a whole zoo of spectral energy density patterns. However, the role played by magnetization in such high-energy emission is still not entirely understood. With the aid of \emph{Fermi}'s second LAT AGN catalog, a comparison with observations in the $\gamma$-ray band was performed, in order to identify the effects of the magnetic field.
    09/2013;
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    ABSTRACT: Broadband emission from relativistic outflows (jets) of active galactic nuclei (AGN) and gamma-ray bursts (GRBs) contains valuable information about the nature of the jet itself, and about the central engine which launches it. Using special relativistic hydrodynamics and magnetohydronamics simulations we study the dynamics of the jet and its interaction with the surrounding medium. The observational signature of the simulated jets is computed using a radiative transfer code developed specifically for the purpose of computing multi-wavelength, time-dependent, non-thermal emission from astrophysical plasmas. We present results of a series of long-term projects devoted to understanding the dynamics and emission of jets in parsec-scale AGN jets, blazars and the afterglow phase of the GRBs.
    Journal of Physics Conference Series 11/2012; 454(1).
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    F. S. Guzman, J. M. Rueda-Becerril
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    ABSTRACT: We present spherically symmetric boson stars as black hole mimickers based on the power spectrum of a simple accretion disk model. The free parameters of the boson star are the mass of the boson and the fourth order self-interaction coefficient in the scalar field potential. We show that even if the mass of the boson is the only free parameter it is possible to find a configuration that mimics the power spectrum of the disk due to a black hole of the same mass. We also show that for each value of the self-interaction a single boson star configuration can mimic a black hole at very different astrophysical scales in terms of the mass of the object and the accretion rate. In order to show that it is possible to distinguish one of our mimickers from a black hole we also study the deflection of light. Comment: 8 revtex pages, 10 eps figures
    Physical review D: Particles and fields 09/2010;

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