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O efeito Sunyaev-Zel\'dovich (ESZ) é uma das mais promissoras técnicas de investigação cosmológica envolvendo os aglomerados de galáxias e a radiação cósmica de fundo (RCF). Tal efeito é uma modificação no espectro planckiano da RCF devido à interação dos fótons com os elétrons energéticos que permeiam o meio intra-aglomerado. Nesta tese de doutorado, vinculamos alguns parâmetros cosmológicos e investigamos a estrutura dos aglomerados de galáxias. Para tal, consideramos amostras de aglomerados para os quais existem medidas conjuntas do ESZ e do brilho em Raios-X. Duas amostras são consideradas, a saber: os 25 dados compilados por de De Filippis et al. (2005), na qual os aglomerados são descritos por modelos isotérmicos (esférico e elíptico), e os 38 dados da amostra de Bonamente et al. (2006) que utilizam um modelo esférico, não isotérmico. Inicialmente, nós investigamos as implicações das diferentes descrições na obtenção do parâmetro de Hubble, $H_0$, no contexto do modelo $\\Lambda$CDM plano e em cosmologias mais gerais, como o $XCDM$ plano e $\\Lambda$CDM com curvatura. Os resultados dependem da amostra e das hipóteses subjacentes. Mostramos que a análise conjunta envolvendo o ESZ/Raios-X de aglomerados, as oscilações acústicas dos bárions e o parâmetro de desvio ({\\it shift parameter}) constituem uma técnica interessante para se determinar $H_0$ e que seu valor depende apenas fracamente da curvatura e do parâmetro da equação de estado da energia escura. Analisando as diversas amostras, nós obtemos também que a descrição elíptica de De Filippis et al. (2005) é a que melhor se ajusta com medidas independentes da física de aglomerados. Posteriormente, utilizando dados de aglomerados (ESZ/Raios-X) e adotando uma des\\-crição puramente cinemática do Universo, obtemos que a probabilidade do parâmetro de desaceleração ser negativo é de 92\\% para a amostra de Bonamente et al. (2006) e de 72\\% para o caso elíptico De Filippis et al. (2005). Ainda nesta linha, simulando os resultados dos vários mapeamentos de Sunyaev-Zeldovich que estão em andamento, discutimos a capacidade dessa técnica (em combinação com dados de Raios-X de aglomerados) para vincular parâmetros cosmológicos. Por outro lado, considerando que a obtenção das distâncias de diâmetro angular de aglomerados pela técnica do ESZ/raios-X depende da relação de dua\\-lidade, investigamos as conseqüências desta dependência de duas formas distintas: (i) testando a consistência entre a validade estrita da relação no modelo de concordância cósmica e as suposições utilizadas para descrever os aglomerados, e (ii) Considerando distâncias independentes (luminosidade e diâmetro angular) obtidas das supernovas Ia e dos aglomerados de galáxias, nós propomos um novo teste para a relação de dualidade que além de auto-consistente é independente de modelo cosmológico. Finalmente, para este teste, discutimos também influência dos diferentes tipos de ajuste das curvas de luz de supernovas. Nossos vínculos para $H_0$ e as conseqüências estatísticas baseadas na relação de dualidade, fornecem uma nova evidência de que a verdadeira geometria dos aglomerados tem uma forma elíptica. Tais resultados também reforçam o interesse pela pesquisa observacional de SZE e de raios-X de aglomerados em moderados e altos {\\it redshifts}. / The so-called Sunyaev-Zeldovich effect (SZE) is one of the most promising techniques for cosmological investigations involving galaxy clusters and the cosmic background radiation (CMB). Such an effect is a modification of the Planckian spectrum due to the interaction between the CMB photons and the hot electrons filling the intracluster medium. In this PhD thesis, we constrain some cosmological parameters and investigate the structure of galaxy clusters based on some samples for which the cluster are endowed with simultaneous measurements of SZE and X-ray surface brightness. Two different samples of galaxy clusters are considered, namely: the 25 data compiled by De Fillippis et al. (2005), and the 38 data sample of Bonamente et al. (2006), based on the non-isothermal spherically symmetric model. Initially, we constrain the value of the Hubble parameter, $ H_0 $, by taking into account the different assumptions underlying the galaxy cluster samples in the context of a flat $\\Lambda$CDM model, as well as, for more general cosmologies like the flat XCDM model and $\\Lambda $CDM with curvature. The results depend on the model assumptions and samples. It is also found that a joint analysis involving ESZ/Raios-X of clusters, the baryon acoustic oscillations (BAO) and shift parameter, constitutes an interesting technique for constraining the Hubble parameter and that its value is weekly dependent on the curvature, as well as on the equation of state parameter of the dark energy. By analysing the different samples, we conclude that the elliptical description of the De Filippis et al. (2005) provides the best quality description in comparison with measurements that are independent from galaxy clusters physics. Furthermore, by using galaxy cluster data (SZE/X-ray) and adopting a purely kinematical description for the universal expansion, we obtain that the decelerating parameter is negative with 92 \\% and 72 \\% of the probability by using the Bonamente et al. (2006) and De Filippis et al. (2005) samples, respectively. By simulating future data set, the ability of the ongoing SZE observations to obtain tighter constraints on the expansion history through SZE/X-ray technique is also discussed. On the other hand, since the SZE/X-ray technique for measuring angular diameter distance of clusters depends on the cosmic distance duality relation (DD relation) validity, we investigate the consequences of such a dependence in two distinct ways: (i) we test the consistence between the strict validity of DD relation in the framework of the $\\Lambda$CDM model (WMAP7) and the different assumptions underlying the galaxy cluster geometries, and (ii) we propose a self-consistent and model-independent test for the DD relation by using type Ia supernovae and galaxy clusters data. Finally, for such a test, we also analyse the influence of the different supernovae light curve fitter methods. Our constraints for $H_0$ and the statistical consequences of the distance duality relation provide a new evidence that the true geometry of galaxy clusters is provided by the elliptical form. Such results also reinforce the interest for the observational research involving the Sunyaev-Zeldovich and X-rays from galaxy clusters at moderate and high {\\it redshifts}.

Cette thèse se focalise sur l'étude des amas de galaxies, via l'effet Sunyaev-Zel'dovich (tSZ), qui consiste en l'interaction de ces même amas avec le fond diffus cosmologique. Pour ce faire j'ai utilisé les données expérimentale de l'instrument HFI du satellite PLANCK. Cette thèse ce découpe en trois parties majeures, (1) L'analyse et le traitement des données en temps, des données brut jusqu'au cartes du ciel, ce focalisant tout particulièrement sur les effets systématiques. (2) Le développement de méthode de séparation de sources, permettant la construction de cartes par émission astrophysique (tout particulièrement l'effet Sunyaev-Zel-dovich) à partir de données multi-fréquences. (3) L'analyse physique des cartes d'effet Sunyaev-Zel'dovich, produit par le gaz d'électron chaud présent dans les amas de galaxies. Ce travail permet la mise en place de contrainte, sur le profile de pression des amas de galaxies, sur la présence de filaments de matière entre des système binaire d'amas de galaxies, ainsi que la mise en évidence du spectre de puissance de l'effet tSZ. / This work is focusing on the study of the thermal Sunyaev-Zel'dovich (tSZ) effect produced by the gaz of hot electrons present in galaxy clusters. This effect consist on the interaction between the Cosmic Microwave Background (CMB) and galaxiy clusters. For this purpuse I used the data from the High Frequency Instrument (HFI) of the PLANCK satellite. This work can be divided in three main parts : (1) The study of systématics effects present in the Time Ordered Data and in the construction of the sky maps. (2) The devellopement of new components seperation methods for the tSZ effect in the context of multi-frequencies observations. (3) The physical analysis of the tSZ effect providing constraints on the galaxy clusters properties. This work allow to put some constraints on the galaxy clusters pressure profile, on the WHIM components present in the inter-clusters medium between binary system of galaxy clusters and on the detection of the tSZ power spectrum with PLANCK.

O efeito Sunyaev-Zel\'dovich (ESZ) é uma das mais promissoras técnicas de investigação cosmológica envolvendo os aglomerados de galáxias e a radiação cósmica de fundo (RCF). Tal efeito é uma modificação no espectro planckiano da RCF devido à interação dos fótons com os elétrons energéticos que permeiam o meio intra-aglomerado. Nesta tese de doutorado, vinculamos alguns parâmetros cosmológicos e investigamos a estrutura dos aglomerados de galáxias. Para tal, consideramos amostras de aglomerados para os quais existem medidas conjuntas do ESZ e do brilho em Raios-X. Duas amostras são consideradas, a saber: os 25 dados compilados por de De Filippis et al. (2005), na qual os aglomerados são descritos por modelos isotérmicos (esférico e elíptico), e os 38 dados da amostra de Bonamente et al. (2006) que utilizam um modelo esférico, não isotérmico. Inicialmente, nós investigamos as implicações das diferentes descrições na obtenção do parâmetro de Hubble, $H_0$, no contexto do modelo $\\Lambda$CDM plano e em cosmologias mais gerais, como o $XCDM$ plano e $\\Lambda$CDM com curvatura. Os resultados dependem da amostra e das hipóteses subjacentes. Mostramos que a análise conjunta envolvendo o ESZ/Raios-X de aglomerados, as oscilações acústicas dos bárions e o parâmetro de desvio ({\\it shift parameter}) constituem uma técnica interessante para se determinar $H_0$ e que seu valor depende apenas fracamente da curvatura e do parâmetro da equação de estado da energia escura. Analisando as diversas amostras, nós obtemos também que a descrição elíptica de De Filippis et al. (2005) é a que melhor se ajusta com medidas independentes da física de aglomerados. Posteriormente, utilizando dados de aglomerados (ESZ/Raios-X) e adotando uma des\\-crição puramente cinemática do Universo, obtemos que a probabilidade do parâmetro de desaceleração ser negativo é de 92\\% para a amostra de Bonamente et al. (2006) e de 72\\% para o caso elíptico De Filippis et al. (2005). Ainda nesta linha, simulando os resultados dos vários mapeamentos de Sunyaev-Zeldovich que estão em andamento, discutimos a capacidade dessa técnica (em combinação com dados de Raios-X de aglomerados) para vincular parâmetros cosmológicos. Por outro lado, considerando que a obtenção das distâncias de diâmetro angular de aglomerados pela técnica do ESZ/raios-X depende da relação de dua\\-lidade, investigamos as conseqüências desta dependência de duas formas distintas: (i) testando a consistência entre a validade estrita da relação no modelo de concordância cósmica e as suposições utilizadas para descrever os aglomerados, e (ii) Considerando distâncias independentes (luminosidade e diâmetro angular) obtidas das supernovas Ia e dos aglomerados de galáxias, nós propomos um novo teste para a relação de dualidade que além de auto-consistente é independente de modelo cosmológico. Finalmente, para este teste, discutimos também influência dos diferentes tipos de ajuste das curvas de luz de supernovas. Nossos vínculos para $H_0$ e as conseqüências estatísticas baseadas na relação de dualidade, fornecem uma nova evidência de que a verdadeira geometria dos aglomerados tem uma forma elíptica. Tais resultados também reforçam o interesse pela pesquisa observacional de SZE e de raios-X de aglomerados em moderados e altos {\\it redshifts}. / The so-called Sunyaev-Zeldovich effect (SZE) is one of the most promising techniques for cosmological investigations involving galaxy clusters and the cosmic background radiation (CMB). Such an effect is a modification of the Planckian spectrum due to the interaction between the CMB photons and the hot electrons filling the intracluster medium. In this PhD thesis, we constrain some cosmological parameters and investigate the structure of galaxy clusters based on some samples for which the cluster are endowed with simultaneous measurements of SZE and X-ray surface brightness. Two different samples of galaxy clusters are considered, namely: the 25 data compiled by De Fillippis et al. (2005), and the 38 data sample of Bonamente et al. (2006), based on the non-isothermal spherically symmetric model. Initially, we constrain the value of the Hubble parameter, $ H_0 $, by taking into account the different assumptions underlying the galaxy cluster samples in the context of a flat $\\Lambda$CDM model, as well as, for more general cosmologies like the flat XCDM model and $\\Lambda $CDM with curvature. The results depend on the model assumptions and samples. It is also found that a joint analysis involving ESZ/Raios-X of clusters, the baryon acoustic oscillations (BAO) and shift parameter, constitutes an interesting technique for constraining the Hubble parameter and that its value is weekly dependent on the curvature, as well as on the equation of state parameter of the dark energy. By analysing the different samples, we conclude that the elliptical description of the De Filippis et al. (2005) provides the best quality description in comparison with measurements that are independent from galaxy clusters physics. Furthermore, by using galaxy cluster data (SZE/X-ray) and adopting a purely kinematical description for the universal expansion, we obtain that the decelerating parameter is negative with 92 \\% and 72 \\% of the probability by using the Bonamente et al. (2006) and De Filippis et al. (2005) samples, respectively. By simulating future data set, the ability of the ongoing SZE observations to obtain tighter constraints on the expansion history through SZE/X-ray technique is also discussed. On the other hand, since the SZE/X-ray technique for measuring angular diameter distance of clusters depends on the cosmic distance duality relation (DD relation) validity, we investigate the consequences of such a dependence in two distinct ways: (i) we test the consistence between the strict validity of DD relation in the framework of the $\\Lambda$CDM model (WMAP7) and the different assumptions underlying the galaxy cluster geometries, and (ii) we propose a self-consistent and model-independent test for the DD relation by using type Ia supernovae and galaxy clusters data. Finally, for such a test, we also analyse the influence of the different supernovae light curve fitter methods. Our constraints for $H_0$ and the statistical consequences of the distance duality relation provide a new evidence that the true geometry of galaxy clusters is provided by the elliptical form. Such results also reinforce the interest for the observational research involving the Sunyaev-Zeldovich and X-rays from galaxy clusters at moderate and high {\\it redshifts}.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-10-16T19:37:30Z No. of bitstreams: 1 GIVAL PORDEUS DA SILVA NETO – DISSERTAÇÃO (PPGFísica) 2015.pdf: 4886479 bytes, checksum: 8589cc7f91d5dab59210f3bf9b9a3d97 (MD5) / Made available in DSpace on 2018-10-16T19:37:30Z (GMT). No. of bitstreams: 1 GIVAL PORDEUS DA SILVA NETO – DISSERTAÇÃO (PPGFísica) 2015.pdf: 4886479 bytes, checksum: 8589cc7f91d5dab59210f3bf9b9a3d97 (MD5) Previous issue date: 2015-05-08 / Capes / A constante de Hubble (H0) é considerada fundamental na cosmologia. Ela é crucial para qualquer modelo cosmológico moderno, pois está relacionada com diversas grandezas cosmológicas, portanto, é de extrema importância a determinação mais restritiva e acurada possível do seu valor. A mais recente estimativa de H0 a partir de métodos locais (z 1), H0 = 73:8 2; 4 kms􀀀1Mpc􀀀1, e a partir de redshifts muito altos (z ' 1070), H0 = 67; 3 1; 2 kms􀀀1Mpc􀀀1, são discrepantes em um nível de con fiança de 2; 4 . Dentro deste contexto, Lima e Cunha (LC), a m de lançar alguma luz sobre este problema, derivou uma nova determinação de H0 utilizando quatro testes cosmológicos em redshifts intermediários (z 1), com base no chamado modelo CDM Plano. Eles obtiveram H0 = 74; 1 2; 2 kms􀀀1Mpc􀀀1, em pleno acordo com as medições locais. Neste trabalho, exploramos a robustez do resultado de LC, procurando por erros sistemáticos e a sua dependência com o modelo cosmológico usado. Nós constatamos que o valor H0 a partir desta análise conjunta é muito fracamente dependente de modelos cosmológico, mas a morfologia adotada para inferir o raio central dos aglomerados de galáxias, altera o resultado, sendo a principal fonte de erros sistemáticos. Concluímos que uma melhor compreensão da morfologia dos aglomerados é fundamental para transformar esse método em um poderoso estimador de H0. / The Hubble constant (H0) is considered a fundamental constant of cosmology. It is crucial for any modern cosmological model, it is related to various cosmological quantities, so it is extremely important a restrictive and accurate determination of its value. The most recent estimate of H0 from local observations (z 1), H0 = 73:8 2; 4 kms􀀀�1Mpc􀀀�1, and from high redshifts (z ' 1070), H0 = 67; 3 1; 2 kms􀀀�1Mpc􀀀�1, are discrepant in a con dence level of 2; 4 . Within this context, Cunha and Lima (LC), in order to shed some light on this problem, derived a new determination of H0 using four cosmological tests at intermediate redshifts (z 1), based on the model called Flat CDM. They obtained H0 = 74; 1 2; 2 kms􀀀�1Mpc􀀀�1, in full agreement with local measurements. In this work, we explore the robustness of the result LC looking for systematic errors and its dependence on the cosmological model used. We found that the H0 value from this combined analysis is very weakly dependent on the underlying cosmological model, but the morphology adopted to infer the core radius of galaxy clusters, changes the estimates being the main source of systematic errors. Hence, we conclude that a better understanding of the morphology of the clusters is essential to transform this method in a powerful cross-check to H0.

Dans cette thèse, nous explorons la phénoménologie de certaines extensions de la relativité générale et de la gravité quantique.Cette recherche est motivée par l’incomplétude des modèles théoriques qui décrivent le comportement de la matière aux échelles cosmologiques.Le model standard de la physique des particules et la relativité générale, combinés ensemble et avec les données expérimentales provenant des collisionneurs de particules et de l’astrophysique, conduisent a des modèles d’univers domines par de la matière invisible. De plus, selon le meilleur de ces modèles, l’univers serait présentement dans une phase d’expansion accélérée et aurait commencer son existence par une singularité spatio-temporelle : le big bang.Ainsi, la physique théorique se trouve mise au défi d’obtenir un model sans singularités et avec moins (ou aucune) matière sombre. Sur ce point, les deux dernières décennies ont étés particulièrement fructueuse : il y a maintenant un grand nombre de théories de gravité modifiée, d’énergie sombre et de gravité quantique qui sont à notre disposition.L’objectif du présent travail est de construire un cadre phénoménologique nous permettant de comparer clairement ces théories les unes aux autres et possiblement d’en réfuter certaines en se basant sur les récentes observations cosmologiques ainsi que celles qui sont encore a venir.La première partie de la thèse est dédiée aux théories de gravité modifiée et d’énergie sombre. La deuxième partie traite de la cosmologie quantique a boucles, et finalement la dernière partie présente une nouvelle façon de sonder l’expansion accélérée de l’univers via l’effet Sunyeav Zeldovich thermique. / In this thesis we explore the phenomenology of some extensions to General Relativity and quantum gravity theories.The motivation for this research lies in the incompleteness of the current theoretical models that describe the behaviour of matter on cosmological scales.The standard model of particle physics and general relativity, combined together along with experimental probes in particle colliders and astrophysics, lead to a model for our universe, which is today dominated by dark matter. Moreover, according to the best model, the universe is currently undergoing an accelerated expansion and had started its existence with a space-time singularity: the big bang.The challenge for theoretical physics is therefore to obtain a model without singularity and with less invisible matter (or none). To this respect, the last two decades have been particularly fruitful: there is a large number of competing modified gravity and dark energy theories as well as quantum gravity proposals at our disposal.The purpose of the work presented here is to set up a phenomenological framework that enables a clear comparison and possible exclusions of these new theories by confronting them to current and future observational data.The first part of the thesis is dedicated to modified gravity and dark energy models. The second part deals with loop quantum cosmology, and the last part is a presentation of a new probe for dark energy: the thermal Sunyaev Zeldovich power spectrum.

Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-10-18T17:24:51Z No. of bitstreams: 1 LEONARDO RIBEIRO COLAÇO – DISSERTAÇÃO (PPGFísica) 2016.pdf: 3372949 bytes, checksum: 8387f15d435a4dd929618ecca701927e (MD5) / Made available in DSpace on 2018-10-18T17:24:51Z (GMT). No. of bitstreams: 1 LEONARDO RIBEIRO COLAÇO – DISSERTAÇÃO (PPGFísica) 2016.pdf: 3372949 bytes, checksum: 8387f15d435a4dd929618ecca701927e (MD5) Previous issue date: 2018 / Capes / As teorias cosmológicas mais comumente aceitas são baseadas no pressuposto de que as constantes fundamentais da natureza, como a constante gravitacional G, a constante de estrutura fina α, entre outras, são de fato constantes. Sendo assim, a suposição de que essas constantes não variam no espaço-tempo é apenas uma hipótese, precisando então ser comprovada a partir de dados experimentais. Neste trabalho, propomos um novo método, independente de modelo cosmológico, capaz de investigar uma possível variação como redshift da constante de estrutura fina, α=е2 /hc, onde é a carga elementar, h é a constante de Planck dividida por 2 π e c é a velocidade da luz. Para tal fim, mostramos também que a técnica combinada do Efeito Sunyaev-Zel'dovich (ESZ) como Brilho Superficial em raios-X (SX) para se medir Distância de Diâmetro Angular (DDA) dos Aglomerados de Galáxias (AG) é dependente da constante de estrutura fina. Mais precisamente,se = 0 (z), argumentamos que os dados atuais dessa técnica fornecem DobsA (z) = 2(z)DA(z), onde DA(z) é a verdadeira DDA para o aglomerado de galáxias e (z) é o campo escalar Dilaton que governa uma possível variação em α. Considerando uma amostra de 25 medidas de DobsA (z), feitas por De Filippis et al. (2005),via ESZ/SX na faixa de redshift 0; 023 < zAG < 0; 784 e estimando medidas de DA(z) do assim chamado Union 2.1 Compilation de Super nova e tipoIa (SNeIa), onde o redshift das SNeIa foram cuidadosamente selecionados para coincidir como redshift do aglomerado de galáxias associado com a maior diferença de redshift obedece a jzAG 􀀀 zSNej < 0; 005. Portanto, foi possível atribuir algumas restrições sobre uma possível variação de α para uma classe de Modelos Dilaton Run away, (z) =1􀀀 ln (1+ z). Nossas análises mostraram que = 􀀀0; 037 0; 157 em 1 , ou seja, nossas análises são compatíveis com uma não variação da constante de estrutura fina. / The most common accepted cosmological theories are base don the assumption that the fundamental constants of nature, suchas the gravitational constant G, the new structure constant α, and others, are infact constant. Thus, the assumption that these constants do not vary with time or space is only a hypothesis, then it needs to be confirmed from experimental data. In this paper, we propose a new method, independent of cosmological models, which is cap able to investigate a possible variation with redshift of the new structure constant, α = e2=hc, where e is the elementary charge, h is Planck's constant over 2π and c is the speed of light. For that purpose, we also show that the combined technique between Sunyaev-Zel'doviche effect (SZE) and X-ray surface brightness (SX) to measure Angular Diameter Distance (ADD) of Galaxy Clusters (GC), dependents on the new structure constant. More precisely, if α = α0 (z) we argue that the current data of this technique gives DobsA (z) = 2(z)DA(z), where DA(z) is the true ADD for galaxy clustersand (z) is the dilatons calareld that governs a possible variation of α. We considere da sample of 25 measurements of Dobs A (z), made by De Filipp is e tal. (2005),via ESZ/SX in the range of redshift 0:023 < zGC < 0:784 and we also estimated DA(z) from the so-called Union 2.1 Super novaeIa(SNEIa) Compilation,where the SNeIa redshifts were carefully selected to match the one soft he as sociated galaxy cluster with the larger redshiftd iαe rencefollows jzGC 􀀀� zSNej < 0:005. There for e,it was possible to put some constraints on a possible variation of α for a class of Dilaton Run a way Model, (z) =1 􀀀� ln (1+ z). We obtained = 􀀀�0; 037 0; 157 in1 , i.e.,our analysis is compatible with an on variation of the new structure constant.

La distribution de masse dans l'Univers telle que tracée par les amas de galaxies constitue une sonde cosmologique puissante. La caractérisation des processus associés à l'origine et à la croissance des grandes structures permet de contraindre des paramètres cosmologiques via l'étude de la distribution des amas en fonction de leur masse et de leur redshift. Cependant, il existe un désaccord statistiquement significatif observé entre les contraintes cosmologiques établies par l'étude des anisotropies primaires du fond diffus cosmologique et celles issues de l'analyse de la distribution des amas de galaxies. Cela pourrait signifier que le modèle standard de la cosmologie est incomplet. L'une des méthodes d'observation des amas de galaxie exploite l'effet Sunyaev-Zel'dovich (SZ) qui permet de contraindre la pression du gaz contenu dans ces derniers. Cette observable peut être directement liée à la masse des amas via une relation d'échelle et un profil de pression. Il est donc essentiel de caractériser précisément ces derniers afin de limiter les potentiels biais et effets systématiques affectant les analyses cosmologiques. Cette thèse présente l'ensemble des travaux réalisés dans cet objectif. Elle porte sur des thématiques allant des observations SZ effectuées avec la caméra NIKA2 installée au télescope de 30 mètres de l’IRAM jusqu'à l'estimation des paramètres cosmologiques en passant par l'analyse des données brutes de NIKA2 et des cartes SZ réalisées.Une part du travail de thèse présenté dans ce document est consacrée à l'étude et l’amélioration des différentes étapes effectuées, depuis les observations d'amas de galaxies au télescope avec la caméra NIKA2 jusqu'à la production de cartes de l'effet SZ. Les procédures développées pour estimer les performances instrumentales de NIKA2 sont détaillées et la chaîne d'analyse utilisée pour réduire les données brutes est présentée.Les travaux réalisés dans cette thèse ont également consisté à caractériser les propriétés thermodynamiques d'amas de galaxies via des analyses jointes combinant les cartes SZ NIKA2 avec des données X mesurées par le satellite XMM-Newton. Nous détaillons les méthodes employées dans le logiciel de traitement des données SZ créé pour le grand programme SZ de NIKA2, la procédure de déprojection non-paramétrique développée pour caractériser le profil de pression des amas de galaxies et les résultats de la première observation SZ avec NIKA2.Les dernières activités présentées sont dédiées aux analyses réalisées afin de quantifier l'impact du grand programme SZ de NIKA2 sur la cosmologie. Nous analysons l'effet des perturbations dynamiques du milieu intra-amas sur la caractérisation du profil de pression avec NIKA2 via l'utilisation d'amas de la simulation numérique MUSIC. Finalement, nous détaillons l'étude permettant d'estimer l'impact d'une variation du profil de pression universel sur l'estimation des paramètres cosmologiques déduite du spectre de puissance de l'effet SZ mesuré par Planck. / The mass distribution in the Universe, as traced by galaxy clusters is a powerful cosmological probe. The characterization of the processes associated with the origin and the growth of the large scale structures enables constraining cosmological parameters by studying the distribution of clusters according to their mass and redshift. However, a tension is observed between the cosmological constraints established by the study of the primary anisotropies of the cosmological background and those resulting from the analysis of the distribution of galaxy clusters. This may imply that our cosmological model is incomplete. The observation of clusters from the Sunyaev-Zel'dovich (SZ) effect allows us to constrain their gas pressure. This observable can be directly linked to the mass of galaxy clusters via a scaling relation and a pressure profile. It is thus essential to characterize the latter precisely in order to limit the potential bias and systematic effects affecting cosmological analyses. This thesis presents the work carried out to this end. It covers topics ranging from SZ observations made with the NIKA2 camera installed at the IRAM 30-metre telescope to the estimation of cosmological parameters, and including the analysis of NIKA2 raw data and the SZ maps produced.Part of the thesis work presented in this document is dedicated to the study and the improvement of the different tasks carried out, from the observations of galaxy clusters with the NIKA2 camera to the production of maps of the SZ effect. The procedures developed to estimate the NIKA2 instrumental performance are detailed and the analysis pipeline used to analyze the raw data is presented.The work carried out in this thesis also consisted in characterizing the thermodynamic properties of galaxy clusters using joint analyzes that combine the NIKA2 SZ maps with X-ray data measured by the XMM-Newton satellite. We detail the methods used in the SZ data processing software created for the NIKA2 SZ large program, the non-parametric deprojection procedure developed to characterize the pressure profile of galaxy clusters and the results of the first SZ observation with NIKA2.The last activities presented are dedicated to the analyses carried out to quantify the impact of the NIKA2 SZ large program on cosmology. We analyze the effect of dynamic disturbances of the intracluster medium on the characterization of the pressure profile with NIKA2 via the use of clusters from the MUSIC N-body simulation. Finally, we detail the study realized in order to estimate the impact of a modification of the universal pressure profile on the estimation of cosmological parameters derived from the power spectrum of the SZ effect measured by Planck.

Cette étude porte sur les plus grandes structures auto-cohérentes connues dans l'univers, les amas de galaxies. Du fait de ses conditions thermodynamiques, leur halo de gaz est complètement ionisé. Ce plasma est observable aux longueurs d'onde X par son émission de freinage, ainsi qu'en submillimétrique et en millimétrique via l'effet Sunyaev-\-Zel'dovich (SZ). Cet effet résulte de la diffusion des photons du champ de rayonnement cosmologique par les électrons du milieu intergalactique. Dans un premier temps, nous avons calculé numériquement le spectre exact de l'effet SZ en prenant en compte le comportement relativiste des électrons du gaz. Ainsi, nous avons mis en évidence la forte dépendance de leur forme en fonction de la température du milieu. A l'aide de cet outil, nous avons analysé les données millimétriques du spectrophotomètre DiaBolo en direction de l'amas RXJ1347-1145. Ces observations à haute résolution spatiale ont permis la détection du plus fort signal SZ mesuré jusqu'à présent, ainsi qu'une émission étendue dont la structuration semble différer de celle observée aux longueurs d'onde X. Nous avons ensuite élargi le domaine spectral d'observation aux longueurs d'onde infrarouges et submillimétriques. Ainsi, nous avons obtenu le spectre de l'amas d'Abell 2163 entre 90~$\mu$m et 2.1~mm. Les contraintes imposées par les mesures infrarouges sur l'émission de poussière ont permis d'optimiser la détermination des paramètres SZ. En extrapolant cette étude au cas des missions spatiales, Planck Surveyor et Herschel, nous avons montré que les données SZ sont une source d'information auto-suffisante. Nous avons ainsi quantifié la précision avec laquelle la température du gaz intra-amas pourrait être déduite des observations SZ faites avec ces instruments.

A small fraction of cosmic microwave background (CMB) photons scatter off electrons in the ionised gas in collapsed structures. This process, known as the Sunyaev-Zel'dovich effect, is usually broken down into a thermal (tSZ) and a kinematic (kSZ) contribution. While the former is sensitive to the random velocities of the electrons in the hot gas, the latter is sourced by the bulk motion of the entire object. In this thesis I measure the signature of both of these effects by cross-correlating CMB data with different tracers of the large-scale structure. I further study how these effects can be used as probes of cosmology and astrophysics. I first report a statistically significant detection of the kSZ effect. This is achieved by combining a cluster catalogue derived from the first year data of the Dark Energy Survey with CMB temperature maps from the South Pole Telescope. I perform the measurement with a differential statistic that isolates the pairwise kSZ signal, providing the first detection of the large-scale motion of clusters using redshifts derived from photometric data. By fitting the pairwise kSZ signal to a theoretical template, I measure the average central optical depth of the cluster sample. I compare the extracted signal to simulations and find good agreement with respect to the signal-to-noise, the constraint on the optical depth, and the corresponding gas fraction. I next study the potential of the kSZ effect as a probe of cosmology, again focussing on the pairwise method. The main challenge is disentangling the cosmologically interesting mean pairwise velocity from the cluster optical depth and the associated uncertainties on the baryonic physics in clusters. Using the Magneticum cosmological hydrodynamical simulations I calibrate a scaling relation between the amplitude of the tSZ signal and the optical depth. I show that this relation can be used to recover an accurate estimate of the mean pairwise velocity from the kSZ signal, and that this effect can therefore be used as a probe of cosmology. I finally derive constraints on feedback from active galactic nuclei by setting limits on their tSZ signal. By combining all-sky microwave, sub-mm, and far-infrared data from the Planck and AKARI satellites, I break the degeneracy between the tSZ signature and extragalactic dust emission. I test the measurement pipeline with a catalogue of galaxy clusters, finding the expected high-significance tSZ detection together with correlated dust emission. I then measure the tSZ signal of spectroscopically confirmed quasi-stellar objects (QSOs), but obtain only a low-significance hint of a tSZ signature. This analysis leads to a lower mean thermal energy than reported in some previous studies which were contaminated by dust emission. A comparison of these results to hydrodynamical simulations can be used as a probe of QSO host masses.