La cassure nucléaire en tant qu'outil pour sonder les corrélations entre les nucléons du noyau a été étudiée d'un point de vue théorique et expérimental.<br />Une théorie, appelée Time Dependant Density Matrix (TDDMP), basée sur une approche de champ moyen et prenant en compte les corrélations à deux corps a été développée. Elle permet de décrire l'évolution dynamique d'un noyau corrélé, notamment pour le mécanisme de cassure nucléaire. Cette étude montre que les distributions en angle relatif des nucléons émis sont très différentes pour des corrélations initiales différentes : deux nucléons dans une configuration spatiale proche donnent lieu à une émission de neutrons avec un petit angle relatif, alors qu'une configuration où les nucléons sont éloignés conduit à de grands angles relatifs.<br />L'6He, noyau borroméen, présente de fortes corrélations entre les deux neutrons de son halo. Deux configurations dominantes sont prédites pour l'état fondamental de ce noyau : la configuration di-neutron (où les deux neutrons sont proches) et la configuration cigare (où les deux neutrons sont de part et d'autre du coeur).<br />La cassure nucléaire de l'6He sur cible de 208Pb a été réalisée au GANIL avec un faisceau SPIRAL : les noyaux d'4He issus de la cassure étaient détectés à l'aide d'un Silicium à pistes couplé à un Silicium-Lithium, et les neutrons à l'aide des détecteurs EDEN et du mur à Neutrons (Neutron Wall) afin d'avoir une large couverture angulaire.<br />Les fonctions de corrélation extraites des données montrent la présence de fortes corrélations à petit angle relatif mais aussi à grand relatif, qui peuvent être attribuées respectivement à la configuration di-neutron et à la configuration cigare. L'état fondamental de l'6He serait donc constitué par une superposition de ces deux configurations.

Le problème de la masse manquante galactique prend sa source dans l'étude des courbes de rotation des galaxies spirales. Une des hypothèses privilégiées durant les vingt dernières années est la présence d'un halo entourant chaque galaxie composé d'objets compacts sombres (les machos) qui peuvent être détectés indirectement par le phénomène gravitationnel de microlentille. Le travail présenté dans cette thèse concerne l'analyse des courbes de lumière de plus de 55 millions d'étoiles des deux Nuages de Magellan, observées de juin 1996 à février 2003, avec les caméras de l'expérience EROS2. Deux études différentes ont été menées dans le but de détecter d'éventuels objets de 10^(-4) à 1000 masses solaires, complétant ainsi les contraintes déjà posées par EROS entre 10^(-7) et 10 masses solaires. Les candidats découverts sont en nombre insuffisant pour rendre compte de la masse manquante et ne permettent pas non plus de confirmer le signal présenté par le groupe MACHO.

本研究以Chen-Chie（Chen and Chie, 2007）所設計的代理人基模型，探討所得分配對彩券銷售額的影響。這篇論文考量了兩種彩券參與函數，一種是採用模糊推論的方法來呈現代理人購買彩券的決定，在此方式下，並未將可能中奬的期望效果納入。另一種則是以預期效用理論為主軸，並且加入主觀認知的中獎機率。除了彩券參與度外，根據Chen and Chie (2007)的設計，還考慮到兩個購買彩券經驗的觀點，分別是自我意識選號及個體間的獨立性。模型中代理人參數並未固定，取而代之的，是讓代理人具有自動產生參數的能力，所有行為的參數是以遺傳演算法取得其適應性。當代理人進行遺傳演算（社會學習）時，代理人對策略的學習會依照區間的設定，進一步作區域性社會學習及全域社會學習。本論文彙集了上述設計，提供了四種彩券市場行為模型，配合不同的所得分配進行模擬，並且利用統計檢定比較其統計量的變化，分析所得分配對彩券銷售額的影響。 / This study addresses the impact of income distribution on lottery sales using an agent-based modeling approach, specifically, the Chen-Chie model (Chen and Chie, 2007). Two kinds of lottery participation function are considered in this thesis. One is more heuristic and does not require agents’ expectations of the odds. In this case, we use the fuzzy inference system to represent agents’ heuristics. The other explicitly takes agents’ expectations of the odds into account, and a formal expected utility maximization approach is taken. In addition to lottery participation, following Chen and Chie (2007), we also consider two additional empirical aspects of lottery plays, namely, conscious selection and state-dependent utilities. The parameters of agents are not fixed; instead, they are autonomous and all behavioral parameters are adaptive via genetic algorithms. While the population genetic algorithms (social learning) are applied, an idea of nearest neighbors learning is used to further distinguish the global social learning from the local social learning. These setups together give us four behavioral models of lottery markets. We then simulate each of these four markets with different income distribution, and then compare their statistic behavior with statistical test to examine the overall effect of income distribution to lottery sales.

Knowledge base systems are brittle when the users of the knowledge base are unfamiliar with its content and structure. Querying a knowledge base requires users to state their questions in precise and complete formal representations that relate the facts in the question with relevant terms and relations in the underlying knowledge base. This requirement places a heavy burden on the users to become deeply familiar with the contents of the knowledge base and prevents novice users to effectively using the knowledge base for problem solving. As a result, the utility of knowledge base systems is often restricted to the developers themselves. The goal of this work is to help users, who may possess little domain expertise, to use unfamiliar knowledge bases for problem solving. Our thesis is that the difficulty in using unfamiliar knowledge bases can be addressed by an approach that funnels natural questions, expressed in English, into formal representations appropriate for automated reasoning. The approach uses a simplified English controlled language, a domain-neutral ontology, a set of mechanisms to handle a handful of well known question types, and a software component, called the Question Mediator, to identify relevant information in the knowledge base for problem solving. With our approach, a knowledge base user can use a variety of unfamiliar knowledge bases by posing their questions with simplified English to retrieve relevant information in the knowledge base for problem solving. We studied the thesis in the context of a system called ASKME. We evaluated ASKME on the task of answering exam questions for college level biology, chemistry, and physics. The evaluation consists of successive experiments to test if ASKME can help novice users employ unfamiliar knowledge bases for problem solving. The initial experiment measures ASKME's level of performance under ideal conditions, where the knowledge base is built and used by the same knowledge engineers. Subsequent experiments measure ASKME's level of performance under increasingly realistic conditions. In the final experiment, we measure ASKME's level of performance under conditions where the knowledge base is independently built by subject matter experts and the users of the knowledge base are a group of novices who are unfamiliar with the knowledge base. Results from the evaluation show that ASKME works well on different knowledge bases and answers a broad range of questions that were posed by novice users in a variety of domains. / text

O Ruído de Baixa Frequência (LFN), tais como o ruído flicker e o Random Telegraph Noise (RTN), são limitadores de performance em muitos circuitos analógicos e digitais. Para transistores diminutos, a densidade espectral de potência do ruído pode variar muitas ordens de grandeza, impondo uma séria limitação na performance do circuito e também em sua confiabilidade. Nesta tese, nós propomos um novo modelo de RTN estatístico para descrever o ruído de baixa frequência em MOSFETs. Utilizando o modelo proposto, pode-se explicar e calcular o valor esperado e a variabilidade do ruído em função das polarizações, geometrias e dos parâmetros físicos do transistor. O modelo é validado através de inúmeros resultados experimentais para dispositivos com canais tipo n e p, e para diferentes tecnologias CMOS. É demonstrado que a estatística do ruído LFN dos dispositivos de canal tipo n e p podem ser descritos através do mesmo mecanismo. Através dos nossos resultados e do nosso modelo, nós mostramos que a densidade de armadilhas dos transistores de canal tipo p é fortemente dependente do nível de Fermi, enquanto para o transistor de tipo n a densidade de armadilhas pode ser considerada constante na energia. Também é mostrado e explicado, através do nosso modelo, o impacto do implante de halo nas estatísticas do ruído. Utilizando o modelo demonstra-se porque a variabilidade, denotado por σ[log(SId)], do RTN/LFN não segue uma dependência 1/√área; e fica demonstrado que o ruído, e sua variabilidade, encontrado em nossas medidas pode ser modelado utilizando parâmetros físicos. Além disso, o modelo proposto pode ser utilizado para calcular o percentil do ruído, o qual pode ser utilizado para prever ou alcançar certo rendimento do circuito. / Low Frequency Noise (LFN) and Random Telegraph Noise (RTN) are performance limiters in many analog and digital circuits. For small area devices, the noise power spectral density can easily vary by many orders of magnitude, imposing serious threat on circuit performance and possibly reliability. In this thesis, we propose a new RTN model to describe the statistics of the low frequency noise in MOSFETs. Using the proposed model, we can explain and calculate the Expected value and Variability of the noise as function of devices’ biases, geometry and physical parameters. The model is validated through numerous experimental results for n-channel and p-channel devices from different CMOS technology nodes. We show that the LFN statistics of n-channel and p-channel MOSFETs can be described by the same mechanism. From our results and model, we show that the trap density of the p-channel device is a strongly varying function of the Fermi level, whereas for the n-channel the trap density can be considered constant. We also show and explain, using the proposed model, the impact of the halo-implanted regions on the statistics of the noise. Using this model, we clarify why the variability, denoted by σ[log(SId)], of RTN/LFN doesn't follow a 1/√area dependence; and we demonstrate that the noise, and its variability, found in our measurements can be modeled using reasonable physical quantities. Moreover, the proposed model can be used to calculate the percentile quantity of the noise, which can be used to predict or to achieve certain circuit yield.

O Ruído de Baixa Frequência (LFN), tais como o ruído flicker e o Random Telegraph Noise (RTN), são limitadores de performance em muitos circuitos analógicos e digitais. Para transistores diminutos, a densidade espectral de potência do ruído pode variar muitas ordens de grandeza, impondo uma séria limitação na performance do circuito e também em sua confiabilidade. Nesta tese, nós propomos um novo modelo de RTN estatístico para descrever o ruído de baixa frequência em MOSFETs. Utilizando o modelo proposto, pode-se explicar e calcular o valor esperado e a variabilidade do ruído em função das polarizações, geometrias e dos parâmetros físicos do transistor. O modelo é validado através de inúmeros resultados experimentais para dispositivos com canais tipo n e p, e para diferentes tecnologias CMOS. É demonstrado que a estatística do ruído LFN dos dispositivos de canal tipo n e p podem ser descritos através do mesmo mecanismo. Através dos nossos resultados e do nosso modelo, nós mostramos que a densidade de armadilhas dos transistores de canal tipo p é fortemente dependente do nível de Fermi, enquanto para o transistor de tipo n a densidade de armadilhas pode ser considerada constante na energia. Também é mostrado e explicado, através do nosso modelo, o impacto do implante de halo nas estatísticas do ruído. Utilizando o modelo demonstra-se porque a variabilidade, denotado por σ[log(SId)], do RTN/LFN não segue uma dependência 1/√área; e fica demonstrado que o ruído, e sua variabilidade, encontrado em nossas medidas pode ser modelado utilizando parâmetros físicos. Além disso, o modelo proposto pode ser utilizado para calcular o percentil do ruído, o qual pode ser utilizado para prever ou alcançar certo rendimento do circuito. / Low Frequency Noise (LFN) and Random Telegraph Noise (RTN) are performance limiters in many analog and digital circuits. For small area devices, the noise power spectral density can easily vary by many orders of magnitude, imposing serious threat on circuit performance and possibly reliability. In this thesis, we propose a new RTN model to describe the statistics of the low frequency noise in MOSFETs. Using the proposed model, we can explain and calculate the Expected value and Variability of the noise as function of devices’ biases, geometry and physical parameters. The model is validated through numerous experimental results for n-channel and p-channel devices from different CMOS technology nodes. We show that the LFN statistics of n-channel and p-channel MOSFETs can be described by the same mechanism. From our results and model, we show that the trap density of the p-channel device is a strongly varying function of the Fermi level, whereas for the n-channel the trap density can be considered constant. We also show and explain, using the proposed model, the impact of the halo-implanted regions on the statistics of the noise. Using this model, we clarify why the variability, denoted by σ[log(SId)], of RTN/LFN doesn't follow a 1/√area dependence; and we demonstrate that the noise, and its variability, found in our measurements can be modeled using reasonable physical quantities. Moreover, the proposed model can be used to calculate the percentile quantity of the noise, which can be used to predict or to achieve certain circuit yield.

Large spectroscopic surveys are trailblazing endeavours in the study of stellar archaeology and near eld cosmology. Access to homogeneous databases of thousands of stellar spectra allow for a detailed and statistically satisfying look into the chemical abundance distribution of our Galaxy and its surrounding satellites, ultimately working towards a better understanding of galactic chemical evolution. This thesis presents the work of three new studies at the current frontier of stellar archaeology. Through the rst look at carbon-enhanced metal-poor (CEMP) stars using H-band spectra, six new CEMP stars and another seven likely candidates were found within the APOGEE database following Data Release 12. These stars have chemical compositions typical of metal-poor halo stars, however the alpha-abundances of two stars indicate possible origins in an accreted dwarf galaxy. A lack of heavy element spectral lines impedes further sub-classi cation of these CEMP stars, however, based on radial velocity scatter, we predict most are not CEMP-s stars which are typically found in binary systems. This preliminary investigation warrants optical observations to con rm the stellar parameters and low metallicities of these stars, to determine the heavy-element abundance ratios and improve the precision in the derived abundances, and to examine their CEMP sub-classi cations. Additionally, the rst results for the spectroscopic follow up to the Pristine survey are presented. Using a sample of 149 stars, a success rate of 70% for finding stars with [Fe/H]<-2.5 and 22% for finding stars with [Fe/H]<-3.0 is reported, significantly higher than other surveys that typically report success rates of 3-4% for recovering stars with [Fe/H]<-3.0. Finally, the new spectral analysis tool StarNet is introduced. A deep neural network architecture is used to examine both synthetic stellar spectra and SDSS-III APOGEE spectral data and can produce the stellar parameters of temperature, gravity, and metallicity with similar or better precision as the APOGEE pipeline values when trained directly with the APOGEE spectra. StarNet is capable of being trained on synthetic data as well, and is able to reproduce the stellar parameters for both synthetic and APOGEE spectra, including low signal-to-noise spectra, with similar precision to training on the APOGEE spectra itself. The residuals between StarNet predictions and APOGEE DR13 parameters are similar to or better than the di erences between the APOGEE DR13 results and optical high resolution spectral analyses for a subset of benchmark stars. While developed using the APOGEE spectral database (real spectra and corresponding ASSET synthetic data with similar normalization functions), StarNet should be applicable to other large spectroscopic surveys like Pristine. / Graduate

The topic of this thesis is the study of the vertical structure of the disk galaxies and their dark matter halos through theoretical modeling and numerical calculations. The basic theoretical model of the galactic disk used involves gravitationally-coupled stars and gas under the force-field of a dark matter halo; the disk is rotationally-supported in the plane and pressure-supported perpendicular to the plane of the galaxy. The first part of the thesis involves evaluating the vertical structure of stars and gas in normal as well as dwarf spiral galaxies. The second part of the thesis deals with probing the dark matter halo density profiles of disk galaxies using both the observed rotation curve and the H i scale height data. Following is the layout of the thesis. Chapter 1 gives a general introduction to the topic of vertical structure of spiral galaxies and their dark matter halos, followed by a broad overview of the theoretical development of the topic and ends with highlighting the motivation and challenges met in this thesis. Chapters 2 & 3 deal with the vertical structure of stars and gas in galaxies, Chapters 4-6 focus on obtaining the dark matter halo density profiles of disk galaxies from the observed rotation curve and the H i scale height data whereas Chapter 7 is devoted to the summary of results and future research plans. Vertical structure of stars and gas in galaxies The vertical thickness of the stars and the gas, namely atomic hydrogen (H i) and molecular hydrogen (H2) in a spiral galaxy, is crucial in regulating the disk dynamics close to the mid-plane, especially in the inner galaxy. However, measuring it observationally is not in general practicable due to the limitations of astronomical observations, and often impossible as in the case of face-on galaxies. Therefore, it is imperative to develop a theoretical model of the galaxy which can predict the thickness of the disk components by using as input parameters the physical quantities, which are more observationally-amenable compared to the disk thickness. The vertical thickness of the disk components is determined by a trade-off between the upward kinetic pressure and the net downward gravitational pull of the galaxy. The fraction of the disk mass due to the stars is an order of magnitude higher than that of the gas in ordinary spiral galaxies, and therefore the gas contribution to the disk gravity is ignored in general. We have developed a multi-component model of gravitationally-coupled stars, HI and H2 subjected to the force-field of an external dark matter halo, and conclusively demonstrated the importance of the inclusion of gas gravity in explaining the steep vertical stellar distribution observed in galaxies. These apart, this model does not implicitly assume a flat rotation curve for the galaxy and therefore is applicable in general to obtain the thickness of stars and gas in dwarfs (with linearly rising rotation curves) as well as in ordinary spirals. In Chapter 2, we investigate the origin of the steep vertical stellar distribution in the Galactic disk. One of the direct fall outs of our above model of the galaxy, which incor¬porates the self-gravity of the gas unlike the earlier theoretical models, lies in explaining the long-standing puzzle of the steep vertical stellar density distribution of the disk galax¬ies near the mid-plane. Over the past two decades, observations revealed that the vertical density distribution of stars in galaxies near the mid-plane is substantially steeper than the sech2 function that is expected for a self-gravitating system of stars under isothermal ap¬proximation. However, the physical origin for this has not been explained so far. We have clearly demonstrated that the inclusion of the self-gravity of the gas in the dynamical model of the Galaxy solves the problem even under the purview of isothermal approximation for the disk components. Being a low dispersion component, the gas resides closer to the mid¬plane compared to the stars, and forms a thin, compact layer near the mid-plane, thereby strongly governing the local disk dynamics. This novel idea, highlighting the significance of gas gravity has produced substantial impact on the field and triggered research activities by other groups in related areas of disk dynamics. The strong effect of the gas gravity on the vertical density profile of the stellar disk indicates that it should also bear its imprint on the Milky way thick disk, as the epoch of its formation 109 years ago is marked by a value of gas fraction, almost an order of magnitude higher than its present day value. Interest-ingly, the findings of the upcoming Gaia mission can be harnessed to verify this theoretical prediction. It may also hold the clue as to the reason behind the absence of thick disk in superthin galaxies. In Chapter 3, we use the same model to theoretically determine the H i vertical scale heights in the dwarf galaxies: DDO 154, Ho II, IC 2574 & NGC 2366 for which most of the necessary input parameters are available from observations. We stress the fact that the observational determination of the gas thickness in these dwarf irregulars is not viable. Nevertheless, it is important to estimate it theoretically as it plays a crucial role in calculating the star-formation activities and other related phenomena. However, two vital aspects have to be taken care of while modeling these dwarf galaxies. Firstly, the mass fraction in gas in these galaxies is comparable to that of the stars, and hence the gas gravity cannot be ignored on any account unlike in the case of large spirals. Secondly, dwarf galaxies have a rising rotation curve over most of the disk unlike the flat rotation curves of ordinary spirals. Both these factors have been considered in developing our model of the dwarf galaxies. We find that three out of the four galaxies studied show a flaring of their H i disks with increasing radius, by a factor of a few within several disk scale lengths. The fourth galaxy (Ho II) has a thick H1 disk throughout. A comparison of the size distribution of H1 holes in the four sample galaxies reveals that of the 20 type 3 holes, all have radii that are in agreement with them being still fully contained within the gas layer. Probing the dark matter halo profiles of disk galaxies The next part of the thesis involves the dynamical study of the shapes and density profiles of galactic dark matter halos using observational constraints on our theoretical model of a spiral galaxy. The density distribution of the dark matter halo is generally modeled using the observed rotation curve of the spiral galaxies. The rotational velocity at any radius is determined by the radial component of the net gravitational force of the galaxy, which, however, is weakly dependent on the shape of the dark matter halo. Therefore, one cannot trace the dark matter halo shape by the observed rotation curve alone. The vertical thickness of the stars and gas, on the other hand, is strongly dependent on the flattening of the dark matter halo, and therefore the observed gas thickness can be used as a diagnostic to probe the halo shape. In this thesis, we have used the double constraints of the rotation curve and the H i thickness data to obtain the best-fit values of the core density, core radius and the vertical-to-planar axis ratio (or flattening) of the dark matter halos of our largest nearby galaxy Andromeda (or M31), a low-surface brightness (LSB) superthin galaxy UGC 7321 and to study the dark matter halo shape of our Galaxy. In Chapter 4, we study the dark matter halo of M31 or Andromeda, the largest nearby galaxy to the Milky Way. We find that M31 has a highly flattened isothermal dark matter halo with the vertical-to-horizontal axis ratio equal to 0.4, which interestingly lies at the most oblate end of the halo shapes found in cosmological simulations. This indicates that either M31 is a unusual galaxy, or the simulations need to include additional physics, such as the effect of the baryons, that can affect the shape of the halo. This is quite a remarkable result as it challenges the popular practice of assuming a spherical dark matter halo in the dynamical modeling of the galaxy In Chapter 5, we have applied this technique to the superthin galaxy UGC 7321. Su¬perthins are somewhat the “extreme” objects in the local Universe because of their high gas fraction and absence of a thick disk component. It is interesting to analyze their so-called extreme characteristics in the light of the physical mechanisms which determined them to understand better the properties of ordinary spirals. We find that UGC 7321 has a spher¬ical isothermal halo, with a core radius almost equal to the disk scale length. This reveals that the dark matter dominates the dynamics of this galaxy at all radii, including the inner parts of the galaxy. This is unlike the case for the large spiral galaxies, where the core radius is typically about 3-4 disk scale lengths. Interestingly, the best-fit halo core density and the core radius are consistent, with deviations of a few percent, with the dark matter fundamental plane correlations, which depict the systematic properties of the dark matter halo in late-type and dwarf spheroidal galaxies. This apart, a high value of the gas velocity dispersion is required to get a better fit to the H i scale height data, although the superthin nature of the stellar disk implies a dynamically cold dynamic galactic disk. However, it explains the low star-formation rates in these galaxies since the Toomre Q criterion (Q < 1) for instability is less likely to be satisfied, and hence the disk is liable to be more stable to star formation. In Chapter 6, we investigate the shape of the dark matter halo in the outer Galaxy. We find that the halo is prolate, with the vertical-to-planar axis ratio monotonically increasing to 2.0 at 24 kpc, or 8 radial disk scale lengths. The resulting prolate-shaped halo can explain several long-standing puzzles in galactic dynamics, for example, it permits long-lived warps thus explaining their ubiquitous nature. It also imposes novel constraints on the galaxy formation models. Finally, in Chapter 7, the thesis is concluded with a summary of the main results and a brief discussion of the scope for future work.

Coronal Mass Ejections (CMEs) are considered to be one of the most energetic events in the heliosphere. Capable of inducing geomagnetic storms on Earth that can cause damage to electronics, a pillar which the modern society we live in leans heavily upon. Being able to accurately predict the arrival of CMEs would present us with the ability to issue timely warnings to authorities and commercial actors, allowing for protective measures to be put in place minimizing the damage. In this study the predicted arrival times and speeds from the Drag Based Model (DBM) and Drag Based Ensemble Model (DBEM) were compared to observational data from a set of 12 events containing fast, Earth-directed Halo CMEs and their corresponding shocks. Although DBM was developed to model CME propagation, varying some parameters allow it to be used for estimating shock/sheath arrival. The results presented in this study indicate that on average DBM performs best when the drag-parameter γ is in the range 0.2 ≤ γ ≤ 0.3. However the variability in the results show that determining a universal value of γ for fast CMEs does not increase the consistency in the model's performance. For completeness, further investigation is needed to account for not only halo CMEs. This will allow to test broader range of variation in the DBEM input parameters.

The Milky Way galaxy, like all spiral galaxies, is surrounded by a roughly spherical distribution of stars called the halo. The halo was largely formed when the galaxy merged with smaller galaxies. The stellar population of the inner halo is dominated by debris from one major such merging event, called the Gaia-Enceladus-Sausage, and the outer halo population is completely built up by several mergers. To properly understand this accretion history, the halo needs to be investigated out to large distances so that as much substructure as possible can be traced. The substructure is expected to leave an imprint in the halo's metallicity structure. In this thesis, we use a catalogue of intrinsically bright stars, giants, to probe the metallicity structure of the halo to large distances. It contains 205,727 stars that all have photometric metallicities from the Pristine survey and distances derived from isochrone fitting, and reaches down to [Fe/H] = -4.0 dex and out to d = 96.16 kpc. Its purity is 90 % and completeness is 67 %. We calculate the distance errors by Monte Carlo simulations and introduce a new cut in colour that is dependent on metallicity to reduce contaminants in the sample. This introduces a metallicity bias in the sample that we can correct for because we coupled metallicity and colour. The correction is done by computing weights for different metallicity bins. The final catalogue allows us to create metallicity distribution functions of the halo as a function of distance. These show us that as heliocentric distance, the distance from the Galactic centre or the Galactic plane increases, the overall metallicity decreases. At the closest distances, the thick disk metallicity peak at -0.7 dex dominates, but as we move further out this smoothly shifts to -1.3 dex and then to -1.6 dex, representing the inner halo, while a peak at -2.2 dex, representing the outer halo, starts to become visible beyond 6 kpc and dominates the metallicity distribution past 26 kpc. These peaks are remnants of merger events in the halo, with the inner halo peak being due to the massive Gaia-Enceladus-Sausage merger and the outer halo peak being due to the many, low-mass and thus low-metallicity galaxies accreted there. We are able to see signals from the Sagittarius stream and Gaia-Enceladus-Sausage's apocentric pile-ups in the metallicity distribution functions, showing that the halo's metallicity changes with not only distance but also sightline. We also detect a diffuse, very metal-poor cloud in the southern footprint that may be an until now unknown structure. This catalogue and its resulting metallicity distribution functions are thus a suitable addition to literature at the metal-poor and distant end, as well as the faint end where e.g. Gaia mission data is unable to provide metallicities and distances. / Vintergatan är, som alla spiralgalaxer, omringad av en ungefärligen sfärisk distribution av stjärnor som kallas halon. Denna halo bildades när galaxen sammansmälte med mindre galaxer. Stjärnpopulationen i den inre halon domineras av stjärnor som kom in med en sådan, väldigt stor, sammanslagning med en annan galax som eter Gaia-Enceladus-Sausage, och den yttre halons stjärnpopulation har helt och hållet byggts upp av sammanslagningar med flera galaxer. För att kunna kartlägga Vintergatans alla sammanslagningar med andra galaxer behöver vi därför undersöka den yttre halon så långt ut som möjligt, för att spåra så mycket substruktur i halon som uppstod till följd av sammanslagningar som möjligt. Sådan substruktur förväntas göra ett avtryck i halons metallicitetsstruktur. I denna masteruppsats används en katalog av intrinsiskt ljusstarka stjärnor, jättar, för att kartlägga halons metallicitetsstruktur till stora avstånd. Katalogen innehåller 205,727 stjärnor som alla har fotometriska metalliciteter från Pristine-undersökningen samt avstånd från isokronanpassning. Den når [Fe/H] = -4.0 dex och d = 96.16 kpc. Mängden jättar i katalogen är 90 % och katalogen behåller 67 % av alla jättar i ursprungskatalogen. Avståndens osäkerhet beräknas med Monte Carlo-simulationer, och det införs ett nytt klipp med färg som är beroende av metallicitet för att undvika kontamination. Detta inför en metallicitetssnedvridning av katalogen som vi kan korrigera eftersom att vi kopplade ihop metallicitet och färg. Korrektionen sker genom att vi beräknar vikter för olika metallicitetsintervall i katalogen. Den slutgiltiga katalogen låter oss skapa metallicitetsdistributioner för halon som beror på avstånd. Dessa distributioner visar oss att när stjärnors avstånd till solen, från galaxens centrum samt från galaxdisken ökar, så minskar den genomsnittliga metalliciteten. Vid väldigt nära avstånd är distributionerna centrerade runt -0.7 dex som motsvarar den tjocka disken, men när avstånden ökar, flyttas denna topp till -1.3 dex och sedan till -1.6 dex, vilket motsvarar den inre halon, samtidigt som en topp vid -2.2 dex, som motsvarar den yttre halon, framträder bortom 6 kpc och dominerar metallicitetsdistributionen för halon bortom 26 kpc. Dessa toppar är kvarlevor efter sammanslagningar mellan Vintergatan och mindre galaxer, där toppen i den inre halon uppstod p.g.a. Gaia-Enceladus-Sausage och toppen i den yttre halon kommer från de många lågmassiva och därmed metallfattiga dvärggalaxer som assimilerats där. Metallicitetsdistributionerna visar signaler från Sagittariusströmmen och Gaia-Enceladus-Sausages apocentriska hopsamlingar, vilket visar att halons metallicitet inte bara beror på avstånd utan även på observationsvinkel. Katalogen visar spår av ett diffust metalfattigt moln i det södra observationsfönstret som potentiellt är en hittills oupptäckt struktur. Denna katalog och dess resulterande metallicitetsdisitributioner är en viktig addering till existerande litteratur i den metallfattiga och avlägsna regimen, samt i den ljussvaga regimen där t.ex. data från Gaiateleskopet inte kan bidra med metallicitets- eller avståndsvärden.