Repercusiones de la entrada en la C.E. sobre el mercado de vinos de calidad en Cataluña

Peer Reviewe

The nuclear and extended mid-infrared emission of Seyfert galaxies

We present subarcsecond resolution mid-infrared (MIR) images obtained with 8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 Mpc) sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog. We use those MIR images to study the nuclear and circumnuclear emission of the galaxies. Using different methods to classify the MIR morphologies on scales of ~400 pc, we find that the majority of the galaxies (75-83%) are extended or possibly extended and 17-25% are point-like. This extended emission is compact and it has low surface brightness compared with the nuclear emission, and it represents, on average, ~30% of the total MIR emission of the galaxies in the sample. We find that the galaxies whose circumnuclear MIR emission is dominated by star formation show more extended emission (650+-700 pc) than AGN-dominated systems (300+-100 pc). In general, the galaxies with point-like MIR morphologies are face-on or moderately inclined (b/a~0.4-1.0), and we do not find significant differences between the morphologies of Sy1 and Sy2. We used the nuclear and circumnuclear fluxes to investigate their correlation with different AGN and SF activity indicators. We find that the nuclear MIR emission (the inner ~70 pc) is strongly correlated with the X-ray emission (the harder the X-rays the better the correlation) and with the [O IV] lambda 25.89 micron emission line, indicating that it is AGN-dominated. We find the same results, although with more scatter, for the circumnuclear emission, which indicates that the AGN dominates the MIR emission in the inner ~400 pc of the galaxies, with some contribution from star formation.Comment: 27 pages, 12 figures, accepted by MNRA

Automating the Procurement of Web Services

As government agencies and business become more dependent on web services, software solutions to automate their procurement gain importance. Current approaches for automating the procurement of web services suffer from an important drawback: neither uncertainty measures nor non-linear, and complex relations among parameters can be used by providers to specify quality-ofservice in offers. In this paper, we look deeply into the roots of this drawback and present a proposal which overcomes it. The key point to achieve this improvement has been using the constraint programming as a formal basis, since it endows the model with a very powerful expressiveness. A XML-based implementation is presented along with some experimental results and comparisons with other approaches.Comisión Interministerial de Ciencia y Tecnología TIC 2000–1106–C02–01Ministerio de Ciencia y Tecnología TIC2003-02737-C02-01Ministerio de Ciencia y Tecnología FIT-150100-2001-7

The nuclear and extended infrared emission of the Seyfert galaxy NGC 2992 and the interacting system Arp 245

We present subarcsecond resolution infrared (IR) imaging and mid-IR spectroscopic observations of the Seyfert 1.9 galaxy NGC 2992, obtained with the Gemini North Telescope and the Gran Telescopio CANARIAS (GTC). The N-band image reveals faint extended emission out to ~3 kpc, and the PAH features detected in the GTC/CanariCam 7.5-13 micron spectrum indicate that the bulk of this extended emission is dust heated by star formation. We also report arcsecond resolution MIR and far-IR imaging of the interacting system Arp 245, taken with the Spitzer Space Telescope and the Herschel Space Observatory. Using these data, we obtain nuclear fluxes using different methods and find that we can only recover the nuclear fluxes obtained from the subarcsecond data at 20-25 micron, where the AGN emission dominates. We fitted the nuclear IR spectral energy distribution of NGC 2992, including the GTC/CanariCam nuclear spectrum (~50 pc), with clumpy torus models. We then used the best-fitting torus model to decompose the Spitzer/IRS 5-30 spectrum (~630 pc) in AGN and starburst components, using different starburst templates. We find that, whereas at shorter mid-IR wavelengths the starburst component dominates (64% at 6 micron), the AGN component reaches 90% at 20 micron. We finally obtained dust masses, temperatures and star formation rates for the different components of the Arp 245 system and find similar values for NGC 2992 and NGC 2993. These measurements are within those reported for other interacting systems in the first stages of the interaction.Comment: 20 pages, 12 figures, accepted by MNRA

An Approach to Temporal-Aware Procurement of Web Services

Es también una ponencia de: International Conference on Service-Oriented Computing: ICSOC 2005: Service-Oriented Computing - ICSOC 2005 pp 170-184. book ISBN: 978-3-540-30817-1 e-ISBN: 978-3-540-32294-8In the context of web service procurement (WSP), temporal–awareness refers to managing service demands and offers which are subject to validity periods, i.e. their evaluation depends not only on quality of service (QoS) values but also on time. For example, the QoS of some web services can be considered critical in working hours (9:00 to 17:00 from Monday to Friday) and irrelevant at any other moment. Until now, the expressiveness of such temporal–aware specifications has been quite limited. As far as we know, most proposals have considered validity periods to be composed of a single temporal interval. Other proposals, which could allow more expressive time–dependent specifications, have not performed a detailed study about all the underlying complexities of such approach, in spite of the fact that dealing with complex expressions on temporality is not a trivial task at all. As a matter of fact, it requires a special design of the so–called procurement tasks (consistency and conformance checking, and optimal selection). In this paper, we present a constraint–based approach to temporal–aware WSP. Using constraints allows a great deal of expressiveness, so that not only demands and offers can be assigned validity periods but also their conditions can be assigned (possibly multiple) validity temporal subintervals. Apart from revising the semantics of procurement tasks, which we previously presented in the first edition of the ICSOC conferences, we also introduce the notion of the covering set of a demand, a topic which is closely related to temporality.Ministerio de Ciencia y Tecnología TIC2003-02737-C02-0

Constraining the X-ray reflection in low accretion rate AGN using XMM-Newton, NuSTAR and Swift

An interesting feature in active galactic nuclei (AGN) accreting at low rate is the weakness of the reflection features in their X-ray spectra, which can result from the gradual disappearance of the torus with decreasing accretion rates. It has been suggested that low luminosity AGN (LLAGN) would have a different reflector configuration compared with high luminosity AGN, either covering a smaller fraction of the sky or simply having less material. Additionally, we note that the determination of the spectral index ($\Gamma$) and the cut-off energy of the primary power-law emission is affected by the inclusion of reflection models, showing the importance of using them to study the accretion mechanism, especially in the case of the LLAGN that have previously shown a high dispersion on the relation between $\Gamma$ and the accretion rate. Our purpose is to constrain the geometry and column density of the reflector in a sample of LLAGN covering a broad X-ray range of energy combining data from XMM-Newton + NuSTAR + Swift of a hard X-ray-flux limited sample of 17 LLAGN from BASS/DR2 with accretion rates $\lambda_{Edd}$=L$_{\rm Bol}$/L$_{\rm Edd}$<10$^{-3}$. We fit all spectra using the reflection model for torus (borus02) and accretion disk (Xillver) reflectors. We found a tentative correlation between the torus column density and the accretion rate, LLAGN shows a lower column density compared with the high-luminosity objects. We also confirm the relation between $\Gamma$ and $\lambda_{Edd}$, with a smaller scatter than previously reported, thanks to the inclusion of high-energy data and the reflection models. Our results are consistent with a break at $\lambda_{Edd}\sim10^{-3}$, suggestive of a different accretion mechanism compared with higher accretion AGN.Comment: Accepted for publication in Astronomy & Astrophysic

Segmentation in 2D and 3D image using Tissue-Like P System

Membrane Computing is a biologically inspired computational model. Its devices are called P systems and they perform computations by applying a finite set of rules in a synchronous, maximally parallel way. In this paper, we open a new research line: P systems are used in Computational Topology within the context of the Digital Image. We choose for this a variant of P systems, called tissue-like P systems, to obtain in a general maximally parallel manner the segmentation of 2D and 3D images in a constant number of steps. Finally, we use a software called Tissue Simulator to check these systems with some examples

Shell structures in aluminum nanocontacts at elevated temperatures

Aluminum nanocontact conductance histograms are studied experimentally from room temperature up to near the bulk melting point. The dominant stable configurations for this metal show a very early crossover from shell structures at low wire diameters to ionic subshell structures at larger diameters. At these larger radii, the favorable structures are temperature-independent and consistent with those expected for ionic subshell (faceted) formations in face-centered cubic geometries. When approaching the bulk melting temperature, these local stability structures become less pronounced as shown by the vanishing conductance histogram peak structure

Analyzing derived metallicities and ionization parameters from model-based determinations in ionized gaseous nebulae

We analyze the reliability of oxygen abundances and ionization parameters obtained from different diagnostic diagrams. For this, we compiled from the literature observational emission line intensities and oxygen abundance of 446 star-forming regions whose O/H abundance was determined by direct estimation of electron temperature. The abundances compiled were compared with the values calculated in this work using different diagnostic diagrams in combination with results from a grid of photoionization models. We found that the [\ion{O}{iii}]/[\ion{O}{ii}] vs. [\ion{N}{ii}]/[\ion{O}{ii}], [\ion{O}{iii}]/H$\beta$ vs. [\ion{N}{ii}]/[\ion{O}{ii}], and ([\ion{O}{iii}]/H$\beta$)/([\ion{N}{ii}]/H$\alpha$) vs. [\ion{S}{ii}]/[\ion{S}{iii}] diagnostic diagrams give O/H values close to the $T_{\rm e}$-method, with differences of about 0.04 dex and dispersion of about 0.3 dex. Similar results were obtained by detailed models but with a dispersion of 0.08 dex. The origin of the dispersion found in the use of diagnostic diagrams is probably due to differences between the real N/O-O/H relation of the sample and the one assumed in the models. This is confirmed by the use of detailed models that do not have a fixed N/O-O/H relation. We found no correlation between ionization parameter and the metallicity for the objects of our sample. We conclude that the combination of two line ratio predicted by photoionization models, one sensitive to the metallicity and another sensitive to the ionization parameter, which takes into account the physical conditions of star-forming regions, gives O/H estimates close to the values derived using direct detections of electron temperatures.Comment: 12 pages, 9 figures, accepted by MNRA