Investigating the AGN-starburst connection in a nearby Seyfert galaxy with ALMA and multiwavelength data

The astrophysical context in which this thesis project lies concerns the comprehension of the mutual interaction between the accretion onto a Super Massive Black Hole (SMBH) and the Star Formation (SF), that take place in the host galaxy. This is one of the key topic of the modern extragalactic astrophysical research. Indeed, it is widely accepted that to understand the physics of a galaxy, the contribution of a possible central AGN must be taken into account. The aim of this thesis is the study of the physical processes of the nearby Seyfert galaxy NGC 34. This source was selected because of the wide collection of multiwavelength data available in the literature. In addition, recently, it has been observed with the Atacama Large Submillimeter/Millimeter Array (ALMA) in Band 9. This project is divided in two main parts: first of all, we reduced and analyzed the ALMA data, obtaining the continuum and CO(6-5) maps; then, we looked for a coherent explaination of NGC 34 physical characteristics. In particular, we focused on the ISM physics, in order to understand its properties in terms of density, chemical composition and dominant radiation field (SF or accretion). This work has been done through the analysis of the spectral distribution of several CO transitions as a function of the transition number (CO SLED), obtained joining the CO(6-5) line with other transitions available in the literature. More precisely, the observed CO SLED has been compared with ISM models, including Photo-Dissociation Regions (PDRs) and X-ray-Dominated Regions (XDRs). These models have been obtained through the state-of-the-art photoionization code CLOUDY. Along with the observed CO SLED, we have taken into account other physical properties of NGC 34, such as the Star Formation Rate (SFR), the gas mass and the X-ray luminosity

Exploring interstellar medium conditions in AGN and star forming galaxies with integral field spectroscopy

The interstellar medium (ISM), made up of ionised, neutral and molecular gas, and interstellar dust, is a fundamental ingredient of galaxy evolution. It is the “primary repository” of galaxies, where star formation (SF) takes place, depositing energy, momentum and chemical enriched material via stellar evolution events (e.g. stellar winds, supernova explosions). ISM properties can be largely influenced also by Active Galactic Nuclei (AGN) activity, that through outflows and jets is capable of heating, compressing and/or removing the gas (feedback). SF and AGN activities are part of the so-called galaxy baryon cycle, that encloses a variety of physical processes, driving and shaping galaxy formation and evolution. This Thesis aims at probing and interpreting ISM properties in different galaxy types, including star forming galaxies and AGN hosts, and in different conditions within a galaxy, through the use of integral field spectroscopy (IFS) and the comparison of the observed data with ionisation models. The use of ISM tracers from optical to submillimeter wavelengths allowed to explore the different processes that affect ISM conditions across both AGN and star forming galaxies, and to assess their impact on the evolution of their hosts. The results obtained represent also a unique test bench for the new generation of photoionisation models, given the unprecedented detail of the analysed data as well as some limitations of current models highlighted in this work

Cell-Mediated Immunity to AAV Vectors, Evolving Concepts and Potential Solutions

International audienceAdeno-associated virus (AAV) vectors are one of the most efficient in vivo gene delivery platforms. Over the past decade, clinical trials of AAV vector-mediated gene transfer led to some of the most exciting results in the field of gene therapy and, recently, to the market approval of an AAV-based drug in Europe. With clinical development, however, it became obvious that the host immune system represents an important obstacle to successful gene transfer with AAV vectors. In this review article, we will discuss the issue of cytotoxic T cell responses directed against the AAV capsid encountered on human studies. While over the past several years the field has acquired a tremendous amount of information on the interactions of AAV vectors with the immune system, a lot of questions are still unanswered. Novel concepts are emerging, such as the relationship between the total capsid dose and the T cell-mediated clearance of transduced cells, the potential role of innate immunity in vector immunogenicity highlighted in preclinical studies, and the cross talk between regulatory and effector T cells in the determination of the outcome of gene transfer. There is still a lot to learn about immune responses in AAV gene transfer, for example, it is not well understood what are the determinants of the kinetics of activation of T cells in response to vector administration, why not all subjects develop detrimental T cell responses following gene transfer, and whether the intervention strategies currently in use to block T cell-mediated clearance of transduced cells will be safe and effective for all gene therapy indications. Results from novel preclinical models and clinical studies will help to address these points and to reach the important goal of developing safe and effective gene therapy protocols to treat human diseases

CO excitation in the Seyfert galaxy NGC7130

We present a coherent multi-band modelling of the CO Spectral Energy Distribution of the local Seyfert Galaxy NGC7130 to assess the impact of the AGN activity on the molecular gas. We take advantage of all the available data from X-ray to the sub-mm, including ALMA data. The high-resolution (~0.2") ALMA CO(6-5) data constrain the spatial extension of the CO emission down to ~70 pc scale. From the analysis of the archival CHANDRA and NuSTAR data, we infer the presence of a buried, Compton-thick AGN of moderate luminosity, L_2-10keV ~ 1.6x10^{43} ergs-1. We explore photodissociation and X-ray-dominated regions (PDRs and XDRs) models to reproduce the CO emission. We find that PDRs can reproduce the CO lines up to J~6, however, the higher rotational ladder requires the presence of a separate source of excitation. We consider X-ray heating by the AGN as a source of excitation, and find that it can reproduce the observed CO Spectral Energy Distribution. By adopting a composite PDR+XDR model, we derive molecular cloud properties. Our study clearly indicates the capabilities offered by current-generation of instruments to shed light on the properties of nearby galaxies adopting state-of-the art physical modelling.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter

The MUSE view of He 2-10: no AGN ionization but a sparkling starburst

We study the physical and dynamical properties of the ionized gas in the prototypical HII galaxy Henize 2-10 using MUSE integral field spectroscopy. The large scale dynamics is dominated by extended outflowing bubbles, probably the results of massive gas ejection from the central star forming regions. We derive a mass outflow rate dMout/dt~0.30 Msun/yr, corresponding to mass loading factor eta~0.4, in range with similar measurements in local LIRGs. Such a massive outflow has a total kinetic energy that is sustainable by the stellar winds and Supernova Remnants expected in the galaxy. We use classical emission line diagnostic to study the dust extinction, electron density and ionization conditions all across the galaxy, confirming the extreme nature of the highly star forming knots in the core of the galaxy, which show high density and high ionization parameter. We measure the gas phase metallicity in the galaxy taking into account the strong variation of the ionization parameter, finding that the external parts of the galaxy have abundances as low as 12 + log(O/H)~8.3, while the central star forming knots are highly enriched with super solar metallicity. We find no sign of AGN ionization in the galaxy, despite the recent claim of the presence of a super massive active Black Hole in the core of He~2-10. We therefore reanalyze the X-ray data that were used to propose the presence of the AGN, but we conclude that the observed X-ray emission can be better explained with sources of a different nature, such as a Supernova Remnant.Comment: 11 pages, 8 Figures, Accepted for publication in A&

A Fog-based Distributed Look-up Service for Intelligent Transportation Systems

Future intelligent transportation systems and applications are expected to greatly benefit from the integration with a cloud computing infrastructure for service reliability and efficiency. More recently, fog computing has been proposed as a new computing paradigm to support low-latency and location-aware services by moving the execution of application logic on devices at the edge of the network in proximity of the physical systems, e.g. in the roadside infrastructure or directly in the connected vehicles. Such distributed runtime environment can support low-latency communication with sensors and actuators thus allowing functions such as real-time monitoring and remote control, e.g. for remote telemetry of public transport vehicles or remote control under emergency situations, respectively. These applications will require support for some basic functionalities from the runtime. Among them, discovery of sensors and actuators will be a significant challenge considering the large variety of sensors and actuators and their mobility. In this paper, a discovery service specifically tailored for fog computing platforms with mobile nodes is proposed. Instead of adopting a centralized approach, we pro-pose an approach based on a distributed hash table to be implemented by fog nodes, exploiting their storage and computation capabilities. The proposed approach supports by design multiple attributes and range queries. A prototype of the proposed service has been implemented and evaluated experimentally

LIFETIME SEDENTARY IS A MAJOR CAUSE OF CHRONIC DISEASES

Aim. Lifetime sedentary, has become in recent decades a dominant feature of the lifestyle that has emotional impact on European countries’population. It’s a social and cultural phenomenon that concerns both sexes, involving all age groups and mostly affects the most disadvantaged social classes. Smoke, obesity and physical inactivity, are primary cause of most chronic diseases. Chronic diseases are major killers in the modern age. The study conducted in Italy is twofold: 1) to estimate how much a sedentary lifestyle contributes to the increase of chronic degenerative diseases; 2) to assess how the attitude towards weekly physical activity produces benefits for health gain. The following diseases have been analyzed: ischemic heart disease, type 2 diabetes, colon cancer, breast cancer, overall mortality. Methods. The indicators used are: number of cases and PAF (Population Attributable Fraction). Surveillance System Steps using the conversion factors used by the reference I-Min Lee’s study. Results. Analysis of the results showed that the prevalence of inactive in the Italian national territory is higher in the south than in the north. Therefore, the fraction of disease attributable to physical inactivity considered varies from region to region presenting around twice in the most virtuous regions, compared to the most needed. Conclusions. The data obtained through the heads of the "inactive" in the individual regions makes it possible to detail the percentage of diseases due to physical inactivity and consequently estimate the terms of health gain that would be obtained if we eliminated / we reduced the prevalence of physical inactivity at the local level. Keywords: Lifetime sedentary, chronic disease, daily physical activit

In vitro cultivation of donor quince shoots affects subsequent morphogenesis in leaf explants.

The effect of in vitro cultivation of donor shoots on subsequent morphogenesis in leaf explants of quince (Cydonia oblonga Mill.) clone BA29 was investigated. Proliferating donor shoots were cultured in ventilated or closed vessels under different photosynthetic photon flux densities (PPFD; 200 and 100 µmol m−2 s−1) with 0, 15, 30 g dm−3 sucrose. Shoots grown in ventilated vessels, especially with sucrose at 15 or 30 g dm−3, were better developed with fully expanded leaves compared to those in standard closed vessels. Leaves collected from pre-treated donor shoots were used to assess regeneration capacity. Somatic embryo production was highest in leaves harvested from shoots cultured in closed vessels with 30 g dm−3 sucrose and in ventilated vessels with 15 and 30 g dm−3 sucrose and under high PPFD which was, in comparison with the control treatment (closed vessel, 30 g dm−3 sucrose and low PPFD), about 2 to 2.5 times higher. A similar response was observed for root regeneration