The Denoised, Deconvolved, and Decomposed Fermi γ\gamma-ray sky - An application of the D3^3PO algorithm

We analyze the 6.5yr all-sky data from the Fermi LAT restricted to gamma-ray photons with energies between 0.6-307.2GeV. Raw count maps show a superposition of diffuse and point-like emission structures and are subject to shot noise and instrumental artifacts. Using the D3PO inference algorithm, we model the observed photon counts as the sum of a diffuse and a point-like photon flux, convolved with the instrumental beam and subject to Poissonian shot noise. D3PO performs a Bayesian inference in this setting without the use of spatial or spectral templates;i.e., it removes the shot noise, deconvolves the instrumental response, and yields estimates for the two flux components separately. The non-parametric reconstruction uncovers the morphology of the diffuse photon flux up to several hundred GeV. We present an all-sky spectral index map for the diffuse component. We show that the diffuse gamma-ray flux can be described phenomenologically by only two distinct components: a soft component, presumably dominated by hadronic processes, tracing the dense, cold interstellar medium and a hard component, presumably dominated by leptonic interactions, following the hot and dilute medium and outflows such as the Fermi bubbles. A comparison of the soft component with the Galactic dust emission indicates that the dust-to-soft-gamma ratio in the interstellar medium decreases with latitude. The spectrally hard component exists in a thick Galactic disk and tends to flow out of the Galaxy at some locations. Furthermore, we find the angular power spectrum of the diffuse flux to roughly follow a power law with an index of 2.47 on large scales, independent of energy. Our first catalog of source candidates includes 3106 candidates of which we associate 1381(1897) with known sources from the 2nd(3rd) Fermi catalog. We observe gamma-ray emission in the direction of a few galaxy clusters hosting radio halos.Comment: re-submission after referee report (A&A); 17 pages, many colorful figures, 4 tables; bug fixed, flux scale now consistent with Fermi, even lower residual level, pDF -> 1DF source catalog, tentative detection of a few clusters of galaxies, online material http://www.mpa-garching.mpg.de/ift/fermi

The Galaxy in circular polarization: all-sky radio prediction, detection strategy, and the charge of the leptonic cosmic rays

The diffuse Galactic synchrotron emission should exhibit a low level of diffuse circular polarization (CP) due to the circular motions of the emitting relativistic electrons. This probes the Galactic magnetic field in a similar way as the product of total Galactic synchrotron intensity times Faraday depth. We use this to construct an all sky prediction of the so far unexplored Galactic CP from existing measurements. This map can be used to search for this CP signal in low frequency radio data even prior to imaging. If detected as predicted, it would confirm the expectation that relativistic electrons, and not positrons, are responsible for the Galactic radio emission. Furthermore, the strength of real to predicted circular polarization would provide statistical information on magnetic structures along the line-of-sights.Comment: 11 pages, 5 figures, revise

Il futuro del pianeta attraverso l'arte contemporanea: i cambiamenti climatici

This paper aims to offer a new perspective regarding the future of the planet through contemporary art, with a focus on predicting and understanding impacts of climate change. Artists involved, in their works, usually are showing the health of the planet. Contemporary art has the potential to play an important role in this global challenge: therefore thanks to the artistic works, we can obtain a very clear picture of Earth’s future. Moreover, contemporary art could have a great power of persuasion in raising awareness among citizens on the risks of climate change. It will seek to make progress on the planet’s future question through contemporary art offering an overview of the artists involved in this kind of works and analyzing their poetics. The aim of this paper is to show how contemporary art can contribute not only to describing the future but even to understanding global challenges such as climate change.Il presente contributo intenderà offrire una nuova prospettiva di lettura del futuro attraverso le arti contemporanee, con un focus preciso verso la previsione e la comprensione della questione dei cambiamenti climatici. Gli artisti interessati a questo tipo di ricerche, nelle loro opere, mirano a mettere in atto un processo che mostri lo stato di salute del pianeta. L'arte contemporanea può dunque giocare un ruolo di primordine: attraverso le opere degli artisti, infatti, si ha uno specchio ben preciso della situazione futura del pianeta. Inoltre l’arte contemporanea può avere una grande forza persuasiva riguardo la sensibilizzazione dei cittadini rispetto a tale problematica.Si cercherà, dunque, di narrare il futuro del pianeta attraverso l’arte contemporanea, offrendo una panoramica degli artisti che si dedicano a questo tipo di ricerche ed analizzandone la loro poetica. L’obiettivo è quello di dimostrare come l’arte contemporanea possa contribuire notevolmente non solo alla descrizione del futuro, ma anche alla comprensione di problematiche globali come quella dei cambiamenti climatici.

Intracluster magnetic fields

Magnetic fields are ubiquitous in the Universe. They have been detected in planets, stars, galaxies, groups and clusters of galaxies, and recently also along filaments, in the large scale structure of the Universe. The aim of this PhD thesis is to study magnetic fields in clusters of galaxies in different evolutionary stages. The presence of magnetic fields in the intracluster medium is clearly indicated by the discovery of diffuse synchrotron emission in the central region and in the outskirts of a larger and larger number of galaxy clusters. These sources, called radio halos and relics, are generated by high energy relativistic electrons moving along the flux lines of weak magnetic fields. These magnetic fields are deeply linked to the dynamical state and the energy transport in the system, and the study of their power spectrum gives information about the energy, the capacity to diffuse, and the ordered motion in the plasma of the relativistic particles. The origin of intracluster magnetic fields is still debated. The most reliable theories suppose a cosmological or a galactic (at z 2-3) origin. In both cases, to match the strengths presently observed, an amplification of the field is required, probably due to cluster formation processes. From the present day observations, intracluster magnetic fields appear to fluctuate over a range of scales and their strength seems to decrease with the distance from the cluster center as a function of the thermal gas density. Merging clusters show low magnetic field central strengths (∼1 μG), while relaxed systems are characterized by higher values (up to some 10 μG). In the radio band, the investigation of the intracluster magnetic field power spectrum can be performed by means of two techniques. Large scale (∼ Mpc) studies can be carried out through the analysis of the emission of large-scale diffuse synchrotron sources. Higher resolution investigations (∼ kpc) are allowed by the analysis of the Faraday rotation of the signal coming from galaxies within or behind galaxy clusters. The coexistence in a galaxy cluster of small and large scales of fluctuation of the magnetic field requires a combination of the two approaches. In fact, in this way, it is possible to follow with continuity the power spectrum of the magnetic field fluctuations from Mpc scales down to kpc scales. Up to now, a detailed study of the magnetic field power spectrum has been performed just in few galaxy clusters. In this work we present the results we obtained by applying these different approaches and their contri- bution to the present day knowledge of intracluster magnetic fields. To perform this kind of studies, we analyzed Very Large Array (VLA, New Mexico, USA) multi- frequency polarimetric data of diffuse radio halos and of discrete sources within or behind galaxy clusters. To constrain the magnetic field fluctuation power spectrum, we compared the observations with the expectations of two- and three-dimensional simulations obtained with the FARADAY software package. The structure of this manuscript is the following. Three main sections can be identified: in Chapter 1 we introduce clusters of galaxies, with particular care to radio emission originating from galaxies and diffuse synchrotron sources (radio halos, relics and mini-halos); in Chapters 2 and 3 we present the contribution of this thesis to the still scanty radio halo statistics and to the study of radio halo properties. We describe the discovery of six new radio halos and the investigation of the X-ray -radio correlation in systems hosting radio halos both on an individual and on a statistical point of view; in Chapter 4 we give an overview about intracluster magnetic fields and the main techniques applied for their investigation and we present statistical studies based on the Faraday rotation effect on the polarimetric properties of radio galaxies. The modeling we adopt and its application to the detailed investigation of the magnetic field in two galaxy clusters are described in Chapters 5, 6, and 7. Finally in Chapter 8 we summarize our conclusions. Throughout this thesis we adopt a ΛCDM cosmology with H0 = 71 km s−1 Mpc−1 , Ωm = 0.27, and ΩΛ = 0.73

Relación entre enfermedades crónicas y salud-enfermedad bucal en adultos brasileros de bajo nivel socioeconómico

Artículo originalEl presente trabajo representó un estudio de prevalencia, transversal, de observación analítica, realizado en el barrio Figueirinha, en el municipio de Xangri-Lá. Localizado en el litoral norte del Estado de Río Grande do Sul, Brasil.Objetivo del mismo fue realizar un relevamiento de las condiciones de salud bucal de los habitantes adultos registrados en el programa Salud de la Familia Figueirinha portadores de diabetes mellitus, hipertensión arterial o ambas patologías y verificar la existencia de alguna correlación con la salud-enfermedad bucal. Material y método: Se recogieron datos de 218 habitantes adultos de los cuales 35 estaban registrados en el programa Hiperdía (Estrategia Salud de la Famlia Figueirinha) como protadores de las patología sistémicas citadas anteriormente. Para la valoración del estado de salud bucal, se evaluó: presencia de la placa bacteriana, sangrado gingival y el índice CPOD (dientes cariados, perdidos y obturados). Resultados: de los 218 habitantes adultos, el 11.5 porciento eran pacientes hipertensos, el 2.3 porciento portadores de diabetes mellitus y el 2.3 porciento portaban ambas enfermedades. Del exámen bucal resultó que el 67.9 porciento presentaba placa bacteriana y el 58.7 porciento sangrado gingival. Se verificó una correlación positiva entre el número de pérdidas dentarias, la hipertensión arterial y diabetes mellitus, con un resultado estadísticamente significante (p=>0.0015). Conclusiones: Es de suma importancia que las personas portadoras de enfermedades sistémicas como la diabetes mellitus y la hipertensión arterial estén integradas a un programa de promoción de salud que tenga en cuenta sus necesidades específicas para el mantenimiento de la salud bucal.(AU

Estudio y análisis de las tecnologías de la información y comunicación (TIC) en odontología en Rio Grande do Sul

Artículo originalAcompañan al trabajo 1 cuadro y 2 gráficas.Objetivo: Analizar el uso de las tecnologías de información y comunicación (TIC) por odontlólogos que egresaron a partir de 2002 en el estado de Rio Grande do Sul Brasil. Método: Análisis estadístico descriptivo de los datos de 217 cuestionarios on line con el software SPSS y test Chi-cuadrado para la obtención de los porcentajes de las variables de comparación (p<0.05) Resultados: El 61,8 porciento son graduados en facultades públicas y 55,8 porciento tiene al menos, una especialidad. El consultorio particular como lugar de trabajo surge en 62,2 porciento de las respuestas; 88,9 porciento no utilizan la historia clínica electrónica, siendo la TIC que más desean incorporar a su práctica, constando en el 53,6 porciento de las respuestas. El 87,2 porciento considera que la informatización ayuda en la práctica clínica reconociendo "agilidad" el 78,9 porciento. La mayor dificultad para la incorporación fue el alto costo (67 porciento). Conclusión: La mayoría de los participantes posee equipamientos electrónicos, pero esa práctica no se extiende alconsultorio y menos aún a servicios públicos. La informatización ayuda en la práctica clínica, brindando mayor agilidad y practicidad. (AU

Statistical properties of Faraday rotation measure from large-scale magnetic fields in intervening disc galaxies

To constrain the large-scale magnetic field strengths in cosmologically distant galax- ies, we derive the probability distribution function of Faraday rotation measure (RM) when random lines of sight pass through a sample of disc galaxies, with axisymmetric large-scale magnetic fields. We find that the width of the RM distribution of the galaxy sample is directly related to the mean large-scale field strength of the galaxy population, provided the dispersion within the sample is lower than the mean value. In the absence of additional constraints on parameters describing the magneto-ionic medium of the intervening galaxies, and in the situation where RMs produced in the intervening galaxies have already been statistically isolated from other RM contributions along the lines of sight, our simple model of the magneto-ionic medium in disc galaxies suggests that the mean large-scale magnetic field of the population can be measured to within ~ 50% accuracy.Comment: 4 pages, Proceedings of FM8 "New Insights in Extragalactic Magnetic Fields", XXXth General Assembly of the IAU, Vienna, August 20-31, 201

Defensive towers and river territories: water architecture in the Zhujiang river basin, Guangdong

[EN] The contribution intends to provide a reading and an in-depth study of the defensive heritage located in the Zhujiang river basin and its delta in Guangdong, China. The paper focuses on the case of diaolou, defensive towers already listed as UNESCO since 2007, built from the sixteenth century until the first half of the twentieth century in Kaiping country. These buildings show an interesting mixture of some local models and typologies and specific characters and styles borrowed from western examples. The research takes as a privileged point of view the relationships that these settlement systems forge with the hydrographic resource, which generates a territorial groove that determines the morphology of the territory and constitutes a historical vehicle of crossings. The arrangement of the fortified towers with respect to the river line is influenced by centripetal and centrifugal actions aimed at responding to defensive needs in the geography of this territory. The heritage of the diaolou seems to respond to two types of defensive demands: one linked to historical facts and the frequent bandit raids that took place in the Guangdong area in the nineteenth century; the other connected to geographical and hydraulic data, as the protection from the phenomenon of inundation and the consequent placement of the towers in the floodplain of the Zhujiang river. The course of the river gets in shape through the architectural technique, in the construction of towers and defensive works and, in the same way, some aspects of the design of this territory are defined through the description of the forms of the river. Architecture, hydraulic engineering and geography work together in defining the form of the settlement and invest the scale of the buildings, generating specific architectural types and morphological characters suitable for responding to the problem of water control, conservation and distribution.Ficarelli, L.; Vacca, V. (2020). Torri difensive e territori fluviali: architetture d’acque nel bacino del fiume Zhujiang, Guangdong. Editorial Universitat Politècnica de València. 907-914. https://doi.org/10.4995/FORTMED2020.2020.11529OCS90791

Mega-parsec scale magnetic fields in low density regions in the SKA era: filaments connecting galaxy clusters and groups

The presence of magnetic fields in galaxy clusters has been well established in recent years, and their importance for the understanding of the physical processes at work in the Intra Cluster Medium has been recognized. Halo and relic sources have been detected in several tens clusters. A strong correlation is present between the halo and relic radio power and the X-ray luminosity. Since cluster X-Ray luminosity and mass are related, the correlation between the radio power and X-ray luminosity could derive from a physical dependence of the radio power on the cluster mass, therefore the cluster mass could be a crucial parameter in the formation of these sources. The goal of this project is to investigate the existence of non-thermal structures beyond the Mpc scale, and associated with lower density regions with respect to clusters of galaxies: galaxy filaments connecting rich clusters. We present a piece of evidence of diffuse radio emission in intergalactic filaments. Moreover, we present and discuss the detection of radio emission in galaxy groups and in faint X-Ray clusters, to analyze non-thermal properties in low density regions with physical conditions similar to galaxy filaments. We discuss how SKA1 observations will allow the investigation of this topic and the study of the presence of diffuse radio sources in low density regions. This will be a fundamental step to understand the origin and properties of cosmological magnetic fields.Comment: 9 pages, 5 figures - to appear as part of 'Cosmic Magnetism' in Proceedings 'Advancing Astrophysics with the SKA (AASKA14)', PoS(AASKA14)10