Temperature and Metallicity in the Intra-cluster Medium of ABELL 262 observed with Suzaku

We studied the temperature and abundance distributions of intra-cluster medium (ICM) in the Abell 262 cluster of galaxies observed with Suzaku. Abell 262 is a bright, nearby poor cluster with ICM temperature of ~2 keV, thus providing useful information about the connection of ICM properties between groups and clusters of galaxies. The observed spectrum of the central region was well-represented by two temperature models, and the spectra for the outer regions were described by single temperature model. With the XIS instrument, we directly measured not only Si, S, and Fe lines but also O and Mg lines and obtained those abundances to an outer region of ~0.43 r_180 for the first time. We found steep gradients for Mg, Si, S, and Fe abundances, while O showed almost flat abundance distribution. Abundance ratios of alpha-elements to Fe were found to be similar to those of the other clusters and groups. We calculated the number ratio of type II to type Ia supernovae for the ICM enrichment to be 3.0 +- 0.6 within 0.1 r_180, and the value was consistent with those for other clusters and groups. We also calculated metal mass-to-light ratios (MLRs) for Fe, O and Mg (IMLR, OMLR, MMLR) with B-band and K-band luminosities of the member galaxies of Abell 262. The derived MLRs were comparable to those for other clusters with kT = 3-4 keV.Comment: 12 pages, 8 figures, accepted for publication in PAS

Shocks and cold fronts in merging and massive galaxy clusters: new detections with Chandra

A number of merging galaxy clusters shows the presence of shocks and cold fronts, i.e. sharp discontinuities in surface brightness and temperature. The observation of these features requires an X-ray telescope with high spatial resolution like Chandra, and allows to study important aspects concerning the physics of the intra-cluster medium (ICM), such as its thermal conduction and viscosity, as well as to provide information on the physical conditions leading to the acceleration of cosmic rays and magnetic field amplification in the cluster environment. In this work we search for new discontinuities in 15 merging and massive clusters observed with Chandra by using different imaging and spectral techniques of X-ray observations. Our analysis led to the discovery of 22 edges: six shocks, eight cold fronts and eight with uncertain origin. All the six shocks detected have $\mathcal{M} < 2$ derived from density and temperature jumps. This work contributed to increase the number of discontinuities detected in clusters and shows the potential of combining diverse approaches aimed to identify edges in the ICM. A radio follow-up of the shocks discovered in this paper will be useful to study the connection between weak shocks and radio relics.Comment: Matched to the MNRAS published version, minor grammar and typo fixe

Self-similarity of temperature profiles in distant galaxy clusters: the quest for a Universal law

We present the XMM-Newton temperature profiles of 12 bright clusters of galaxies at 0.4<z<0.9, with 5<kT<11 keV. The normalized temperature profiles (normalized by the mean temperature T500) are found to be generally self-similar. The sample was subdivided in 5 cool-core (CC) and 7 non cool-core (NCC) clusters, by introducing a pseudo-entropy ratio sigma=(T_IN/T_OUT)X(EM_IN/EM_OUT)^-1/3 and defining the objects with sigma<0.6 as CC clusters and those with sigma>=0.6 as NCC clusters. The profiles of CC and NCC clusters differ mainly in the central regions, with the latters exhibiting a marginally flatter central profile. A significant dependence of the temperature profiles on the pseudo-entropy ratio sigma is detected by fitting a function of both r and sigma, showing an indication that the outer part of the profiles becomes steeper for higher values of sigma (i.e. transitioning towards the NCC clusters). No significant evidence of redshift evolution could be found within the redshift range sampled by our clusters (0.4<z<0.9). A comparison of our high-z sample with intermediate clusters at 0.1<z<0.3, showed how both the CC and NCC clusters temperature profiles have experienced some sort of evolution. This can be due by the fact that higher z clusters are at less advanced stage of their formation and did not have enough time to create a relaxed structure, characterized by a central temperature dip in CC clusters and by flatter profiles in NCC clusters. This is the first time that a systematic study of the temperature profiles of galaxy clusters at z>0.4 has been attempted, as we were able to define the closest possible relation to a Universal law for the temperature profiles of galaxy clusters at 0.1<z<0.9, showing a dependence on both the state of relaxation of the clusters and the redshift.Comment: 14 pages, 8 figures, A&A in press, minor changes (language editing

The Entire Virial Radius of the Fossil Cluster RXJ1159+5531: I. Gas Properties

Previous analysis of the fossil-group/cluster RXJ1159+5531 with X-ray observations from a central Chandra pointing and an offset-North Suzaku pointing indicate a radial intracluster medium (ICM) entropy profile at the virial radius ($R_{\rm vir}$) consistent with predictions from gravity-only cosmological simulations, in contrast to other cool-core clusters. To examine the generality of these results, we present three new Suzaku observations that, in conjunction with the North pointing, provide complete azimuthal coverage out to $R_{\rm vir}$. With two new Chandra ACIS-I observations overlapping the North Suzaku pointing, we have resolved $\gtrsim$50\% of the cosmic X-ray background there. We present radial profiles of the ICM density, temperature, entropy, and pressure obtained for each of the four directions. We measure only modest azimuthal scatter in the ICM properties at $R_{\rm 200}$ between the Suzaku pointings: 7.6\% in temperature and 8.6\% in density, while the systematic errors can be significant. The temperature scatter, in particular, is lower than that studied at $R_{\rm 200}$ for a small number of other clusters observed with Suzaku. These azimuthal measurements verify that RXJ1159+5531 is a regular, highly relaxed system. The well-behaved entropy profiles we have measured for RXJ1159+5531 disfavor the weakening of the accretion shock as an explanation of the entropy flattening found in other cool-core clusters but is consistent with other explanations such as gas clumping, electron-ion non-equilibrium, non-thermal pressure support, and cosmic ray acceleration. Finally, we mention that the large-scale galaxy density distribution of RXJ1159+5531 seems to have little impact on its gas properties near $R_{\rm vir}$.Comment: Accepted for publication in Ap

Extracting few representative reconciliations with Host-Switches (Extended Abstract)

Phylogenetic tree reconciliation is the approach commonly used to in- vestigate the coevolution of sets of organisms such as hosts and symbionts. Given a phylogenetic tree for each such set, respectively denoted by H and S, together with a mapping φ of the leaves of S to the leaves of H, a reconciliation is a mapping ρ of the internal vertices of S to the vertices of H which extends φ with some constraints. Given a cost for each reconciliation, a huge number of most parsimonious ones are possible, even exponential in the dimension of the trees. Without further information, any biological interpretation of the underlying coevolution would require that all optimal solutions are enumerated and examined. The latter is however impossible without pro- viding some sort of high level view of the situation. One approach would be to extract a small number of representatives, based on some notion of similarity or of equivalence between the reconciliations. In this paper, we define two equivalence relations that allow one to identify many reconciliations with a single one, thereby reducing their number. Extensive experiments indicate that the number of output solutions greatly decreases in general. By how much clearly depends on the constraints that are given as input

XMM-Newton observation of the cluster ZW 1305.4+2941 in the field SA 57

We report the details of an XMM observation of the cluster of galaxies ZW 1305.4+2941 at the intermediate redshift of z=0.241, increasing the small number of interesting X-ray constraints on properties of ~3 keV systems above z=0.1. Based on the 45 ks XMM observation, we find that within a radius of 228 kpc the cluster has an unabsorbed X-ray flux of 2.07 +/- 0.06 x 10^{-13} erg/cm^2/s, a temperature of kT = 3.17 +/-0.19 keV, in good agreement with the previous ROSAT determination, and an abundance of 0.93 (+0.24,-0.29} solar. Within r_500 = 723 +/- 6 kpc the rest-frame bolometric X-ray luminosity is L_X (r_500)= 1.25 +/- 0.16 x 10^{44} erg/s. The cluster obeys the scaling relations for L_X, T and the velocity dispersion derived at intermediate redshift for kT < 4 keV, for which we provide new fits for all literature objects. The mass derived from an isothermal NFW model fit is, M_vir = 2.77 +/- 0.21 x 10^{14} solar masses, with a concentration parameter, c = 7.9 +/- 0.5.Comment: 9 pages, 7 colour figures, accepted for publication in ApJ. Corrected typo on the fraction of blue galaxie

L’impatto della pandemia di Covid-19 sul comportamento dei consumatori di vino e degli enoturisti: i cambiamenti, i loro driver e nuove prospettive

Il vino è diventato uno dei pilastri del mercato agroalimentare internazionale, con un crescente bacino di consumatori in tutto il mondo. In questo contesto, l'Italia è una delle forze trainanti del settore vitivinicolo a livello mondiale per produzione, consumo ed in termini commerciali accanto ad attori storici come Francia o Spagna e ad attori più recenti, appartenenti al cosiddetto Nuovo Mondo, come gli USA. Parallelamente, il fenomeno dell'enoturismo si è notevolmente espanso portando ad una grande differenziazione della domanda e dell'offerta, nonché ad una crescente pressione competitiva per gli attori che intendono operare nel business. Poiché il crescente corpo della letteratura sull'enoturismo risale per lo più ai primi anni 2000 e si concentra sulle cosiddette regioni vinicole del Nuovo Mondo, c'è necessità di informazioni aggiornate sulle ultime evoluzioni del settore. Inoltre, la crisi generata dal Covid-19 ha rivoluzionato la nostra quotidianità, alterando fortemente le dinamiche dei mercati e delle società mondiali. Questa tesi di dottorato mira ad esplorare se e come l'attuale pandemia ha modificato il comportamento dei consumatori di vino e degli enoturisti. In particolare, il capitolo 1 analizza l'effetto del primo lockdown sui consumi di vino degli italiani combinando tecniche descrittive e regressione logistica binaria. I capitoli 2 e 3, invece, applicano un modello ad equazioni strutturali (SEM) per esplorare l’impatto della pandemia sulle intenzioni a viaggiare degli enoturisti. Nello specifico, il capitolo 2 si concentra sugli enoturisti italiani e francesi includendo gli effetti sia del coinvolgimento personale con il vino, che del coinvolgimento situazionale legato ai periodi di confinamento, della solidarietà verso i produttori nazionali, della paura del contagio e dei vincoli finanziari causati dalla pandemia. Il capitolo 3 propone uno studio simile su un panel di enoturisti statunitensi, ma include nuove variabili: l'attitudine al rischio ed i vincoli di tempo al viaggio legati al Covid. La modellazione simultanea di fattori positivi e limitanti rispetto al comportamento dei consumatori mira a ridurre le potenziali distorsioni che possono sorgere quando, come in studi esistenti, viene considerato soltanto uno dei due aspetti. Inoltre, questo progetto investiga i recenti sviluppi del turismo del vino analizzando il fenomeno emergente delle esperienze enoturistiche online. In particolare, il capitolo 4 esplora i driver dell'interesse a partecipare all'enoturismo online, considerando fattori legati a Covid (sia positivi che negativi) ed altri elementi chiave riportati dalla letteratura. Infine, il capitolo 5 presenta i risultati preliminari di un innovativo esperimento di scelta svolto su un panel di enoturisti italiani ed incentrato sulle degustazioni di vino online, la forma prevalente di enoturismo a distanza adottata dagli operatori del settore.Wine has become one of the pillars of the international agri-food market, to the point that it currently attracts billions of consumers worldwide every year. In the wine scenario, Italy is a leading force in wine production, consumption, and trade next to historical players like France or Spain and more recent New World actors like the USA. In parallel, the wine tourism phenomenon has grown dramatically leading to a great offer and supply differentiation, and to increasing competitive pressure for actors willing to operate in the business. Since the growing body of wine tourism literature mostly dates back to the early 2000s and focuses on so-called New World wine regions, there is a need for updated information on the latest sector evolutions. However, the Covid-19 outbreak brought unmatched, profound changes to our known normality, jeopardising international trade, tourism, and all countries’ economies and societies. With this in mind, this doctoral thesis aims at exploring the effects of the current pandemic on wine consumers and wine tourists behaviour. Notably, chapter 1 analyses the effect of the lockdown on Italians’ wine consumption combining descriptive techniques with binary logistic regression. Chapters 2 and 3, instead, apply structural equation modelling (SEM) to explore if and how the pandemic has affected wine tourism intentions. Precisely, chapter 2 focuses on Italian and French wine tourists travel intentions and considers the effects of personal involvement with wine, situational involvement with wine connected to the times of home confinement, solidarity, Covid phobia and financial constraints caused by the pandemic. Chapter 3 proposes a similar study on USA wine regions visitors but embodying also risk attitude and Covid-related time constraints to travelling. The simultaneous modelling of positive factors and constraints aims to reduce potential distortions that can arise when, as past studies have done, only positive or negative drivers of consumers behaviour are considered. Pursuant to the need of exploring recent wine tourism developments, the present work further analyses the emerging phenomenon of online wine tourism experiences. Specifically, chapter 4 explores the antecedents of interest in partaking in online wine tourism, embodying Covid-related factors (both positive and negative) jointly with other key drivers reported by the literature. Finally, Chapter 5 presents the preliminary findings of a pioneering choice experiment on a panel of Italian wine tourists involving online wine tastings, which are the prevalent form of remote wine tourism adopted by the sector’s practitioners

Family firms’ growth and sustainability. A case study from the Italian food industry.

openThe purpose of this work is to analyze the conditions that allow family firms, which are often portrayed as conservative and reluctant to invest in innovation (Duran et al., 2016), to take a leadership role in sustainable developments. We choose this topic because around the world, the concerns about resource over-consumption, environmental degradation and social inequity, have resulted in calls for a transition toward a more sustainable society and economy, that involve all the economic agents (Adams et al., 2016). This is because they are recognized as part of the problem as well as of the solution, being positioned to effect positive changes in the direction of sustainability (Adams et al., 2016). In this context, since roughly more than two thirds of all the firms across the globe, can be considered family-owned businesses (Duran et al., 2016), an understanding of their particular behavior toward the three pillars of sustainability (economic, social and environmental) is pressing. The peculiarity of their conduct, derives from the fact that while they are perceived to be good employers and committed to social and environmental responsibility, thanks to the family’s influence (Zellweger, 2017), they tend to take distances from radical changes (Duran et al., 2016), losing in this way the opportunity to lead the path toward sustainable developments as, among the necessary means for achieving a sustainable economic growth, innovation and flexibility are crucial (Adams et al., 2016). For these reasons, to give an answer to the research question “How can a family firm grow, following a sustainability path?” we choose to use a qualitative analysis on two family firms, operating in one of the most challenging industries in term of sustainability-related issues: the food industry. Indeed, the selected family businesses are Rigoni di Asiago S.r.l, and Beehoney&co (a pseudonym for the company name) , two companies operating in the Italian food industry. The first case study, based on the analysis of Rigoni di Asiago, has been carried out through the use of secondary sources of data, focused on the topics highlighted by the theoretical framework of the thesis. The conclusions obtained from the analysis of the Rigoni di Asiago case study, meaning the initial answer to the research question, have been integrated with a second case study, based on Beehoney&co, a small family firm located in Padua and similar to Rigoni in terms of origins, business and family’s values. The second case has been conducted through a semi-structured interview with the founders of the company, Margherita and Andrea Beehoney , that are still working for their business having a dominant influence in company’s decisions, even if the firm has been passed on to their second daughter, part of the second generation of the family. As stated above, the analysis of Beehoney&co, has been carried out to test the conclusions obtained from the first case study and the selection of such a type of firm, has been driven by the desire of finding a company in which the link between the family and the company’s actions was not influenced by nonfamily members or other external pressures, typical of larger firms. So, the findings obtained from the Rigoni di Asiago case, combined with the insights revealed by the Beehoney&co analysis, have been useful to integrate the theoretical framework of the thesis, drawing a more complete answer to the research question.The purpose of this work is to analyze the conditions that allow family firms, which are often portrayed as conservative and reluctant to invest in innovation (Duran et al., 2016), to take a leadership role in sustainable developments. We choose this topic because around the world, the concerns about resource over-consumption, environmental degradation and social inequity, have resulted in calls for a transition toward a more sustainable society and economy, that involve all the economic agents (Adams et al., 2016). This is because they are recognized as part of the problem as well as of the solution, being positioned to effect positive changes in the direction of sustainability (Adams et al., 2016). In this context, since roughly more than two thirds of all the firms across the globe, can be considered family-owned businesses (Duran et al., 2016), an understanding of their particular behavior toward the three pillars of sustainability (economic, social and environmental) is pressing. The peculiarity of their conduct, derives from the fact that while they are perceived to be good employers and committed to social and environmental responsibility, thanks to the family’s influence (Zellweger, 2017), they tend to take distances from radical changes (Duran et al., 2016), losing in this way the opportunity to lead the path toward sustainable developments as, among the necessary means for achieving a sustainable economic growth, innovation and flexibility are crucial (Adams et al., 2016). For these reasons, to give an answer to the research question “How can a family firm grow, following a sustainability path?” we choose to use a qualitative analysis on two family firms, operating in one of the most challenging industries in term of sustainability-related issues: the food industry. Indeed, the selected family businesses are Rigoni di Asiago S.r.l, and Beehoney&co (a pseudonym for the company name) , two companies operating in the Italian food industry. The first case study, based on the analysis of Rigoni di Asiago, has been carried out through the use of secondary sources of data, focused on the topics highlighted by the theoretical framework of the thesis. The conclusions obtained from the analysis of the Rigoni di Asiago case study, meaning the initial answer to the research question, have been integrated with a second case study, based on Beehoney&co, a small family firm located in Padua and similar to Rigoni in terms of origins, business and family’s values. The second case has been conducted through a semi-structured interview with the founders of the company, Margherita and Andrea Beehoney , that are still working for their business having a dominant influence in company’s decisions, even if the firm has been passed on to their second daughter, part of the second generation of the family. As stated above, the analysis of Beehoney&co, has been carried out to test the conclusions obtained from the first case study and the selection of such a type of firm, has been driven by the desire of finding a company in which the link between the family and the company’s actions was not influenced by nonfamily members or other external pressures, typical of larger firms. So, the findings obtained from the Rigoni di Asiago case, combined with the insights revealed by the Beehoney&co analysis, have been useful to integrate the theoretical framework of the thesis, drawing a more complete answer to the research question

Financial Literacy and Portfolio Diversification: An Analysis Using Spanish Portfolio Micro Data

openIn recent decades we have witnessed a substantial increase in research around the topic of financial literacy and its implications in the financial decisions and habits of individuals. In an ever-changing industry where the spectrum of choice is increasingly wide and sophisticated, it is crucial to find factors that can guide economic actors towards informed and economically healthier decisions. Starting from the Spanish Survey of Financial Competences (2016 edition), the following analysis investigates the financial literacy of individuals and how this impacts on the diversification of the portfolio in terms of categories of assets held