A radio and infrared exploration of the Cygnus X-3 environments

To confirm, or rule out, the possible hot spot nature of two previously detected radio sources in the vicinity of the Cygnus X-3 microquasar. We present the results of a radio and near infrared exploration of the several arc-minute field around the well known galactic relativistic jet source Cygnus X-3 using the Very Large Array and the Calar Alto 3.5~m telescope. The data this paper is based on do not presently support the hot spot hypothesis. Instead, our new observations suggest that these sources are most likely background or foreground objects. Actually, none of them appears to be even barely extended as would be expected if they were part of a bow shock structure. Our near infrared observations also include a search for extended emission in the Bracket $\gamma$ (2.166 $\mu$m) and $H_{2}$ (2.122 $\mu$m) lines as possible tracers of shocked gas in the Cygnus X-3 surroundings. The results were similarly negative and the corresponding upper limits are reported.Comment: Accepted for publication in A&A; 5 pages, 4 figure

Chandra X-ray counterpart of KS 1741-293

We aim to investigate the nature of the high energy source KS 1741-293 by revisiting the radio and infrared associations proposed in the early 1990s. Our work is mostly based on the analysis of modern survey and archive data, including the NRAO, MSX, 2MASS and Chandra archives, and catalogues. We also have obtained deep CCD optical observations by ourselves. The coincidence of KS 1741-293 with an extended radio and far-infrared source, tentatively suggested in 1994, is no longer supported by modern observational data. Instead, a Chandra source is the only peculiar object found to be consistent with all high-energy error circles of KS 1741-293 and we propose it to be its most likely X-ray counterpart. We also report the existence of a non-thermal radio nebula in the vicinity of the KS 1741-293 position with the appearance of a supernova remnant. The possibility of being associated to this X-ray binary is discussed.Comment: 5 pages, 4 figures, 2 tables. Accepted for publication in Astronomy & Astrophysic

Demand and Storage Management in a Prosumer Nanogrid Based on Energy Forecasting

Energy efficiency and consumers' role in the energy system are among the strategic research topics in power systems these days. Smart grids (SG) and, specifically, microgrids, are key tools for these purposes. This paper presents a three-stage strategy for energy management in a prosumer nanogrid. Firstly, energy monitoring is performed and time-space compression is applied as a tool for forecasting energy resources and power quality (PQ) indices; secondly, demand is managed, taking advantage of smart appliances (SA) to reduce the electricity bill; finally, energy storage systems (ESS) are also managed to better match the forecasted generation of each prosumer. Results show how these strategies can be coordinated to contribute to energy management in the prosumer nanogrid. A simulation test is included, which proves how effectively the prosumers' power converters track the power setpoints obtained from the proposed strategy.Spanish Agencia Estatal de Investigacion ; Fondo Europeo de Desarrollo Regional

Lattice dynamics study of cubic Tb2O3

"This is the peer reviewed version of the following article: Ibáñez, Jordi, Oriol Blázquez, Sergi Hernández, Blas Garrido, Plácida Rodríguez-Hernández, Alfonso Muñoz, Matias Velázquez, Philippe Veber, and Francisco Javier Manjón. 2018. Lattice Dynamics Study of Cubic Tb 2 O 3. Journal of Raman Spectroscopy 49 (12). Wiley: 2021 27. doi:10.1002/jrs.5488, which has been published in final form at https://doi.org/10.1002/jrs.5488. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] We report a joint experimental and theoretical study of the lattice dynamics of cubic Tb2O3. Up to 16 optical Raman-active modes have been observed with polarized and unpolarized Raman scattering measurements on a high-quality Tb2O3 single crystal. The measured wavenumbers have been compared with those of other rare-earth (RE) and related sesquioxides with cubic (C-type or bixbyite) structure. First-principles calculations have allowed us to assign the symmetry of the experimentally observed Raman-active modes. Additional lattice-dynamical calculations on the related cubic RE sesquioxides Dy2O3, Gd2O3, Eu2O3, and Sm2O3 indicate that the phonon wavenumbers of the Raman-active modes in these compounds are monotonically reduced with increasing the lattice parameter along the Dy2O3-Tb2O3-Gd2O3-Eu2O3-Sm2O3 series, thus prompting for a revision of the experimental Raman spectra of some of these compounds (mainly Eu2O3 but also Gd2O3).This study was supported by the Spanish Ministerio de Economía y Competitividad under Projects MAT2015-71070-REDC, MAT2015-71035-R, MAT2016-75586-C4-2-P/3-P, and FIS2017-2017-83295-P.Ibanez, J.; Blazquez, O.; Hernandez, S.; Garrido, B.; Rodríguez-Hernández, P.; Munoz, A.; Velazquez, M.... (2018). Lattice dynamics study of cubic Tb2O3. 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