2 resultados para Polarisation
em AMS Tesi di Laurea - Alm@DL - Università di Bologna
Resumo:
Large-scale structures can be considered an interesting and useful "laboratory" to better investigate the Universe; in particular the filaments connecting clusters and superclusters of galaxies can be a powerful tool for this intent, since they are not virialised systems yet. The large structures in the Universe have been studied in different bands, in particular the present work takes into consideration the emission in the radio band. In the last years both compact and diffuse radio emission have been detected, revealing to be associated to single objects and clusters of galaxies respectively. The detection of these sources is important, because the radiation process is the synchrotron emission, which in turn is linked to the presence of a magnetic field: therefore studying these radio sources can help in investigating the magnetic field which permeates different portions of space. Furthermore, radio emission in optical filaments have been detected recently, opening new chances to further improve the understanding of structure formation. Filaments can be seen as the net which links clusters and superclusters. This work was made with the aim of investigating non-thermal properties in low-density regions, looking for possible filaments associated to the diffuse emission. The analysed sources are 0917+75, which is located at a redshift z = 0.125, and the double cluster system A399-A401, positioned at z = 0.071806 and z = 0.073664 respectively. Data were taken from VLA/JVLA observations, and reduced and calibrated with the package AIPS, following the standard procedure. Isocountour and polarisation maps were yielded, allowing to derive the main physical properties. Unfortunately, because of a low quality data for A399-A401, it was not possible to see any radio halo or bridge.
Resumo:
In political debates, the media[tisation] can determine the use of language with the aim to increase their spectacularisation and polarisation, possibly by means of criticism and humour, respectively. These linguistic strategies are often used in order to shape what was defined by Goffman as one’s face. Politicians, in particular, can recur to facework in a double sense: shaping their own face positively and/or that of their opponents negatively. Starting from the sociologic theory of face by Goffman and Levinson, with the help of corpus analysis tools, this research investigated the ways in which various forms of criticism and forms of humour were conducted in 3 electoral debates on a national scale (Germany, Ireland, and New Zealand) and 1 debate for the municipal election in Rome. The transcripts were revised after automatic transcriptions were extracted or found online, of which the audio-visual content is available on the Internet. The CADS research aimed to investigate the role that criticism and humour played within each participant’s discourse, and to identify differences and similarities among the strategies used by political leaders and moderators in different countries, and in different cultural, political, and media contexts.