Search results for "Llar"

S5 0836+710 Ground and Space VLBI images

2020

Detailed studies of relativistic jets in active galactic nuclei (AGN) require high-fidelity imaging at the highest possible resolution. This can be achieved using very long baseline interferometry (VLBI) at radio frequencies, combining worldwide (global) VLBI arrays of radio telescopes with a space-borne antenna on board a satellite. We present multiwavelength images made of the radio emission in the powerful quasar S5 0836+710, obtained using a global VLBI array and the antenna Spektr-R of the RadioAstron mission of the Russian Space Agency, with the goal of studying the internal structure and physics of the relativistic jet in this object. The RadioAstron observations at wavelengths of 18…

ALMA third image of lensed quasar PKS 1830-211

2020

Strong gravitational lensing distorts our view of sources at cosmological distances but brings invaluable constraints on the mass content of foreground objects and on the geometry and properties of the Universe. We report the detection of a third continuum source toward the strongly lensed quasar PKS 1830-211 in ALMA multi-frequency observations of high dynamic range and high angular resolution. This third source is point-like and located slightly to the north of the diagonal joining the two main lensed images, A and B, 0.3" away from image B. It has a flux density that is 140 times weaker than images A and B and a similar spectral index, compatible with synchrotron emission. We conclude th…

High-energy monitoring of NGC 4593 II. Broad-band spectral analysis: testing the two-corona model

2019

It is widely believed that the primary X-ray emission of AGN is due to the Comptonisation of optical-UV photons from a hot electron corona, while the origin of the 'soft-excess' is still uncertain and matter of debate. A second Comptonisation component, called warm corona, was therefore proposed to account for the soft-excess, and found in agreement with the optical-UV to X-ray emission of a sample of Seyfert galaxies. In this context, we exploit the broadband XMM-Newton and NuSTAR simultaneous observations of the Seyfert galaxy NGC 4593 to further test the so called "two corona model". The NGC 4593 spectra are well reproduced by the model, from the optical/UV to the hard X-rays. Moreover, …

Testing warm Comptonization models for the origin of the soft X-ray excess in AGNs

2018

The X-ray spectra of many active galactic nuclei (AGN) show a soft X-ray excess below 1-2 keV on top of the extrapolated high- energy power law. The origin of this component is uncertain. It could be a signature of relativistically blurred, ionized reflection, or the high-energy tail of thermal Comptonization in a warm (kT $\sim$ 1 keV), optically thick ($\tau\simeq$ 10-20) corona producing the optical/UV to soft X-ray emission. The purpose of the present paper is to test the warm corona model on a statistically significant sample of unabsorbed, radio-quiet AGN with XMM-newton archival data, providing simultaneous optical/UV and X-ray coverage. The sample has 22 objects and 100 observations…

Unveiling the environment and faint features of the isolated galaxy CIG 96 with deep optical and HI observations

2018

Context. Asymmetries in atomic hydrogen (HI) in galaxies are often caused by the interaction with close companions, making isolated galaxies an ideal framework to study secular evolution. The AMIGA project has demonstrated that isolated galaxies show the lowest level of asymmetry in their HI integrated profiles compared to even field galaxies, yet some present significant asymmetries. CIG 96 (NGC 864) is a representative case reaching a 16% level. Aims. Our aim is to investigate the HI asymmetries of the spiral galaxy CIG 96 and what processes have triggered the star-forming regions observed in the XUV pseudo-ring. Methods. We performed deep optical observations at CAHA1.23m, CAHA2.2m and V…

2020

In this paper a comprehensive system-level computational model of oculomotor pathways is presented. This model shows the necessity of embedding internal models of muscles biomechanics in the cerebellar Vermis to realize fast saccadic eye movements based on predicting the changes in muscles lengths. First, the eye biomechanics are described by nonlinear equations during “slow” and “fast” movements. Afterward, by analyzing these equations, a computational model, is deduced. Furthermore, each part of this model is interpreted as a possible function of an element in the oculomotor pathways based on physiological and anatomical pieces of evidence. In this model, two internal feedback loops compe…

2014

Pupil dilation under constant illumination is a physiological marker where modulation is related to several cognitive functions involved in daily decision making. There is evidence for a role of pupil dilation change during decision-making tasks associated with uncertainty, reward-prediction errors and surprise. However, while some work suggests that pupil dilation is mainly modulated by reward predictions, others point out that this marker is related to uncertainty signaling and surprise. Supporting the latter hypothesis, the neural substrate of this marker is related to noradrenaline (NA) activity which has been also related to uncertainty signaling. In this work we aimed to test whether …

Incorporation of zeolitic imidazolate framework (ZIF-8)-derived nanoporous carbons in methacrylate polymeric monoliths for capillary electrochromatog…

2017

A series of metal organic frameworks-derived nanoporous carbons originating from zeolitic imidazolate framework-8 (ZIF-8) crystals as precursors have been prepared via varying the preparation conditions. The ZIF-8-derived carbons were subsequently admixed in the methacrylate monomers containing polymerization mixtures and polymerized to obtain monolithic columns for capillary electrochromatography (CEC). The effect of particle size and content of the ZIF-8-derived carbon materials in the polymerization mixture on the performance of the hybrid monolithic columns was investigated in detail. The resulting composites were characterized using scanning electron microscopy. Using short time UV-ini…

Determination of glyphosate in water samples with the combination of cation-exchange chromatography and capillary electrophoresis

2003

An analytical method for determination of pesticide Glyphosate in water as a combination of cation-exchange chromatography and capillary electrophoresis is presented. Pure water was spiked with Glyphosate at concentrations 0.1, 0.25, 0.5 and 1 mM and percolated through a strong cation-exchange column packed with Dowex 50WX4-400 resin in its H+ form. The extract was further analyzed by capillary electrophoresis in indirect detection mode. The calibration curve for the pesticide in the range 0.1–2.5 mM was linear and with high degree of reproducibility. The obtained recoveries for all the studied concentrations amount 85%. Afterwards, the possibility to determine Glyphosate at the concentrati…

Stone winepress and cellars in the Iberian territory of Kelin (Utiel-Requena) (6th-2nd centuries BC)

2013

Los primeros indicios sobre cultivo de la vid en la comarca de Requena-Utiel son unas semillas carbonizadas de la ciudad ibérica de Kelin (Caudete de las Fuentes, València) del siglo VII a.C. No obstante, la expansión de su cultivo corresponde a los siglos V-III a.C. como se infiere del gran número de semillas carbonizadas, lagares de piedra, bodegas y ánforas, algunas con marcas pre y postcocción. En la actualidad, se conocen unos diez lagares de piedra de distinta capacidad, situados entre el valle del Cabriel y las ramblas de la Alcantarilla y Los Morenos. Todos ellos se encuentran asociados a materiales arqueológicos que permiten datarlos como ibéricos y, en uno de ellos se ha excavado …