Thesis (doctoral)--Universität Leipzig. / Lebenslauf. "Erscheint Gleichzeitig als Hft. 6 der Leipziger Ägyptologischen Studien." Includes bibliographical references (p. 11-13).

L'époque de la réionisation, qui s'étend pendant le premier milliard d'années de l'Univers, correspond à la période où les premières étoiles et galaxies apparaissent. Dans ce contexte, l'enjeu majeur de cette thèse est d'étudier la formation de ces premières structures et leur rétroaction radiative sur leur environnement. Pour cela, j'utilise différentes méthodes de simulations numériques permettant de modéliser le transfert radiatif dans les galaxies, dans un cadre cosmologique.En particulier, les plus petites galaxies seraient celles qui apportent la majorité des photons nécessaires à ioniser l'Univers. J'explore cette hypothèse dans une première partie à l'aide de simulations radio-hydrodynamiques avec le code RAMSES-RT, ciblant trois petites galaxies avec une très haute résolution spatiale et temporelle. Je me suis d'abord intéressé aux mécanismes régulant la production et le transfert de photons ionisants dans les galaxies, et j'ai montré que les explosions de supernovae en sont un facteur essentiel. Ensuite, j'ai exploré les propriétés observables dérivées à partir de ces simulations.Dans un second temps, j'ai développé une extension au code Monte Carlo de transfert radiatif MCLya prenant en compte la polarisation du rayonnement et l'émission diffuse dans une simulation. J'ai utilisé ce code pour post-traiter une simulation d'un blob Lyman-alpha, une source étendue d'émission Lyman-alpha, et étudier ses propriétés de polarisation à l'aide de pseudo-observations. Contrairement à ce qui était proposé précédemment, j'ai pu montrer que la polarisation n'était pas un indicateur aussi utile qu'espéré pour tracer l'origine des photons Lyman-alpha / The Epoch of Reionisation, which spans during the first billion year of te Universe, corresponds to the period during which the first stars and galaxy form. In this context, the main topic of this thesis is to study the formation of those early structures and their radiative feedback to their environment. For this purpose, I use various numerical simulations tools designed to model the radiative transfer in galaxies in a cosmological framework.More specifically, I look at very small galaxies, which are believed to contribute the bulk of the photons required to reionise the Universe. I explore this idea using radiative hydrodynamics simulations performed with RAMSES-RT, focusing on three small galaxies with a very high spatial and temporal resolution. I first detail the mechanism that regulate te production and escape of ionising photons in galaxies, and I show that supernovae explosions are a crucial element for this regulation. I then started to investigate the observable properties of those galaxies.In a second part of my thesis, I developped an extension to the Monte Carlo radiative transfer code MCLya to take light polarisation into account and to model the diffuse emission. I applied this code to post-process the simulation of a Lyman-alpha blob (an extended Lyman-alpha source), and to study its polarisation properties with mock observations. Contrary to what was suggested before, I showed that polarisation is not a strong tracer of the origin of Lyman-alpha photons

L'époque de la Réionisation est la transition d'un Univers rempli d'hydrogène neutre et relativement froid à un Univers rempli de gaz chaud et ionisé. Cette transition intervient à peine un milliard d'années après le Big Bang. Le processus de réionisation est dû à l'émission de photons ionisants par les premières étoiles et premières galaxies à se former. Le travail de cette thèse consiste en l'étude de la formation des galaxies pendant et après la Réionisation, et en particulier de l'impact de cette dernière sur la formation stellaire. En utilisant des modèles et des simulations numériques, il est possible d'étudier le processus de Réionisation de l'Univers en détail, avec comme contraintes les observations du milieu inter-galactique et des galaxies à haut redshift. Dans cette thèse, je me suis concentré dans un premier temps sur les effets de coupure de la formation stellaire pendant et après la Réionisation de manière globale. J'ai eu accès à des simulations d'un nouveau type, qui modélisent la propagation du rayonnement ionisant couplé avec la dynamique et avec l'évolution des propriétés de la matière dans un volume cosmologique. J’ai aussi étudié en détail l'impact de la Réionisation sur les plus petites galaxies, en particulier, le cas de leur distribution spatiale dans l'Univers local, dans le but de reproduire et comprendre certaines observations. / The Epoch of Reionization is the transition from a Universe full of cold and neutral hydrogen to a hot and ionized Universe: it occurs one billion years after the Big Bang. The Reionization is driven by the ionizing photons emitted by the first stars and galaxies. This thesis analyses the galaxy formation during and after the Reionization. Focusing on the feedback of the Reionization on the stellar formation. Using models and numerical simulations, we can study in details the Reionization process. Observations of galaxies and intergalactic medium at high redshift constrain those models, as well as observations of the local Universe, which is the only place where low luminosity galaxies can be observed. In this thesis, I focus on the radiative suppression of stellar formation caused by the Reionization. For this purpose, I used a new generation of simulations, able to take into account the radiative transfer as well as the hydrodynamics in a cosmological volume. I also studied in details the Reionization of the smallest galaxies, focusing on their spatial distribution in the local Universe to understand and reproduce the observations. I looked in particular at the distribution of satellites around M31-like galaxies and find that the observed vast plane of satellites can be reproduced in our models.

No description available.

L'objectif de cette thèse est d'analyser l'information issue du nouveau capteur radar ASAR d'ENVISAT et des futurs capteurs polarimétriques en bande X pour l'estimation de la rugosité et de l'humidité du sol. Les résultats obtenus par le capteur aéroporté RAMSES montrent le faible potentiel des radars en bande X à 30° pour la discrimination des classes de rugosité. Néanmoins, cette étude a montré qu'il est possible d'identifier un état structural de surface dégradé en raison de la présence d'une croûte de battance et de distinguer les parcelles fraîchement labourées. L'utilisation du capteur ASAR a permis de définir les configurations radar optimales pour une meilleure estimation de l'humidité (polarisation HH, et faibles incidences) et de la rugosité du sol (polarisations HH et HV, et fortes incidences). Après avoir observé une faible corrélation entre les mesures expérimentales et celles simulées par le modèle de rétrodiffusion IEM, nous avons appliqué la calibration semi-empirique du modèle IEM proposée par Baghdadi et al. (2004) dans le but de mieux reproduire le coefficient de rétrodiffusion radar sur des sols nus en milieu agricole. Les résultats obtenus montrent que cette calibration permet de mieux restituer le signal radar. Des procédures d'inversion ont été utilisées pour estimer l'humidité à partir des signaux ASAR. Les résultats obtenus montrent une nette amélioration de l'estimation de l'humidité quand deux angles d'incidence sont utilisés (l'une faible et l'autre élevé). L'utilisation des données en mode multi-polarisation n'améliore pas l'estimation de l'humidité par rapport à l'utilisation d'une seule polarisation (amélioration inférieure à 1%).

The master thesis Art Criticism of Ramses Younan focuses on text analysis of theoretical work by Egyptian painter and critic Ramses Younan which deals with the topics of art criticism and theory. It examines and analyzes main topics of his work and offers their interpretation in the art-history and art-theory contexts. It also discusses its meaning in the wider perspective of Egyptian modernity and modern art and its possible value for reevaluation of the art theory field in the Middle East. The paper consists of three main chapters and appendix. The appendix contains a collection of selected essays of the author, translated from Arabic to Slovak. The first chapter deals with the art- historical background of author's theoretical production. The second one concentrates around the text analysis. The third chapter presents critical reactions on author's work by theorists of different geographical and cultural background. It suggests different ways of reading and understanding of the cultural and art-history impact on the local and global modern art history.

The Battle of Kadesh fought between the Hittites and Egyptians in Syria is one of the biggest chariot battles in ancient Near Eastern history. Previous research has shown that the significance of the Battle of Kadesh is derived predominately from a tactical and strategic level. This dissertation introduces the idea that although this is a tactical battle, its overall importance comes from applying a holistic approach, in particular, investigating the causes and consequences, alongside the battle. By extending prior work on tactics and strategy to include an identified cause, the Zannanza Affair, and the consequences, the Treaty of Kadesh and the Royal Marriages it makes allowances for a wider evaluation of the battle. Attention is paid to textual, iconographical and archaeological sources to gain a better understanding of the battle. The findings provide support for the argument that the murder of the Hittite prince in the Zannanza Affair led to crucial military innovations and operational changes adopted by the Hittites and Egyptians, which impacted how they fought on the battlefield. While a considerable amount of research has been done on the Hittite and Egyptian military organisations, the role of the elite units on the battlefield has largely not been explored. The Treaty of Kadesh and the Royal Marriages were a critical turning point in Hittite-Egyptian relations offering a strong alliance and unprecedented peace in the ancient Near East. Traditionally, the Battle of Kadesh has been viewed as a tactical battle. However, for further advances, the contribution of this study prompts a rethinking of the latter by placing the operational details of the battle in a broader context encouraging new research on the social, cultural and political aspects, which is crucial for the understanding of the importance of the Battle of Kadesh, on and off the battlefield. / Biblical and Ancient Studies / M. A. (Ancient Near Eastern Studies)

Representational artistic works were researched as visual evidence for the social, political, religious and economic lifestyles of the ancient Egyptian elite. The aims were to comprehend the status of elite women and to challenge the hypothesis that during the New Kingdom they enjoyed an increased social status in comparison to that of their predecessors. Many artistic works were analysed (tomb and palace wall scenes, statues, obelisks and personal artefacts), on the quest for evidence for the roles of elite women in events, practices and rituals at the time when the objects were created. Various international museums were visited and personal observations are correlated with expert publications. The study concludes that the status of elite women in the New Kingdom was both significantly different and exalted in comparison with the status of their counterparts during earlier dynasties. / OLD TESTAMENT & ANCIENT NE / MA (ANC NEAR EAST STUDIES)

Representational artistic works were researched as visual evidence for the social, political, religious and economic lifestyles of the ancient Egyptian elite. The aims were to comprehend the status of elite women and to challenge the hypothesis that during the New Kingdom they enjoyed an increased social status in comparison to that of their predecessors. Many artistic works were analysed (tomb and palace wall scenes, statues, obelisks and personal artefacts), on the quest for evidence for the roles of elite women in events, practices and rituals at the time when the objects were created. Various international museums were visited and personal observations are correlated with expert publications. The study concludes that the status of elite women in the New Kingdom was both significantly different and exalted in comparison with the status of their counterparts during earlier dynasties. / OLD TESTAMENT and ANCIENT NE / MA (ANC NEAR EAST STUDIES)