Early-type galaxies (ETGs) are typically thought of as 'red and dead' with little to no star formation and old stellar populations. Their detailed kinematics measured locally suggest an interesting array of formation mechanisms and high-redshift observations are starting to reveal a two-phase evolutionary path for the most massive galaxies. In this thesis, I take a combined approach to studying the formation of ETGs. I look to distant quiescent galaxies in one of the densest regions of the early Universe and at the fossil record of a local galaxy to shed light on some of the unsolved mysteries of how ETGs evolved. Using the unique multiplexed instrument, the K-band Multi-Object Spectrograph (KMOS), the evolution of galaxies at both low and high redshift were studied as part of this thesis. I maximised the capabilities of this multi-integral field unit (IFU) near-infrared (NIR) instrument to study different aspects of ETG evolution. With 24 separate IFUs, many quiescent galaxies were efficiently observed in a massive high-redshift cluster as part of the KMOS Cluster Survey. Coupling KMOS spectroscopy with Hubble Space Telescope photometry, I studied the ages, kinematics, and structural properties of the galaxies. I then analysed the detailed properties of a massive local ETG with interesting kinematics, IC 1459. Coupling the NIR IFU data from KMOS with a large mosaic of optical data from the Multi-Unit Spectroscopic Explorer, I was able to study the spatially resolved kinematics, stellar populations, and initial mass function of the galaxy. The work presented in this thesis provides some interesting clues as to the formation of ETGs and possible diversity of their evolutionary paths.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, we present a two-dimensional mapping of the central region of the active galaxies NGC 1068 and NGC 2110, using near infrared integral field spectroscopy with the instrument NIFS (Near-infrared Integral Field Spectrograph) on the Gemini North Telescope. For NGC1068, we present measurements for the stellar kinematics by fitting the CO absorptions in the H and K bands, at a spatial resolution of � 8 pc. For NGC2110 we used K band observations at a spatial resolution of � 24pc. Besides the stellar kinematics, we present flux distributions and kinematics for the molecular and ionized gas emission lines. The stellar velocity fields for both galaxies present a typical rotation pattern, being well represented by a kinematic model, in wich the stars have circular orbits in the plane of disk and are subject to a Plummer potential. The mass of the supermassive black hole in the center of NGC1068 was estimated to be M = 4.3+6 −3 × 107M� from M −s? relation. For NGC 2110, M was estimated to be M = 1.3+2.5 −0.7 × 108M�. The maps for the kinematics and flux distributions of the emitting gas for NGC 2110 were obtained by fitting the H2 l2.1218μm and H I l2.1661μm emission-line profiles by Gauss-Hermite series. The H2 presents extended emission in the whole field of observation, while the Brg is extended only in the southeast northwest direction. The H2 emission is consistent with emission of gas excited by thermal processes, such as gas heated by X-rays from the AGN or shocks. We estimated an excitation temperature of � 2100−2700K for H2 emitting gas. The masses of molecular and ionized gas were estimated from fluxes of the H2 l2.1218 and Brg emission lines as MH2 � 1.4 × 103M� and MHII � 1.7 × 106M�, respectively. The gas velocity fields present a rotation pattern similar to those observed for the stars. In addition, the H2 velocity field presents other kinematic components. Two spiral structures are observed in blueshifts to the north of the nucleus and redshifts to the south of it. If these kinematic structures are originated from emission of gas located in the plane of the galaxy, they can be interpreted as gas flow towards the nucleus (inflow) of the galaxy along the spiral arms. In this case, the mass inflow rate is estimated to be � 4 × 10−4M� yr−1. Another kinematic component observed for H2 emitting gas was interpreted as ejection of gas from the nucleus (outflow) within a bi-cone with a mass outflow rate of � 4.66 × 10−4M� yr−1. / Neste trabalho, mapeamos bidimensionalmente a região central das galáxias ativas NGC 1068 e NGC 2110, a partir de observações no infravermelho próximo (IV) com o instrumento NIFS (Nearinfrared Integral Field Spectrograph) do telescópio Gemini Norte. Para NGC1068 apresentamos medidas da cinemática estelar a partir de ajustes das bandas de absorção do CO nas bandas H e K, com resolução espacial de ≈ 8 pc. Já para NGC 2110, a resolução espacial é ≈ 24pc e utilizamos as absorções do CO na banda K para obter a cinemática estelar. Realizamos também medidas da cinemática e distribuições de fluxos para o gás molecular e para o g´as ionizado, emissor de linhas na banda K. Os campos de velocidades estelar para as duas galáxias apresentam um padrão de rotação típico, sendo bem representados por um modelo cinemático no qual as estrelas descrevem órbitas circulares no plano do disco e estão sujeitas a um potencial de Plummer. A massa do buraco negro supermassivo (BNS) no centro de NGC 1068 foi estimada como sendo M = 4.3+6 −3 × 107M⊙ a partir da relação M −s?. Para NGC 2110, a massa do BNS foi estimada em M = 1.3+2.5 -0.7 × 108M⊙. Os mapas para as distribuições de fluxos e cinemática do gás para NGC 2110 foram obtidos por ajustes de séries de Gauss-Hermite aos perfis das linhas de emissão do H2 l2.1218μm e H I l2.1661μm (Brg). Observa-se emissão estentida para o H2 em todo o campo de observação, enquanto que a emissão de Brγ é estendida somente na direçãoo sudeste noroeste. A emissão H2 é consistente com emissão de gás excitado por processos térmicos, tais como choques ou aquecimento do gás por raios-X emitidos pelos AGNs (Active Galactic Nuclei). Estimamos uma temperatura de excitação entre 2100−2700K para o gás emissor de H2. Massas de gás ionizado e molecular foram estimadas a partir dos fluxos das linhas de emissão Brγ e H2 l2.1218 e valem MHII ≈ 1.7 × 106M⊙ e MH2 ≈ 1.4 × 103M⊙, respectivamente. Os campos de velocidades do gás apresentam um padrão de rotação típico, semelhante ao observado para as estrelas. Adicionalmente a este padrão de rotação observam-se diferentes componentes cinemáticas para o H2. São observadas duas estruturas em forma de espiral em blueshifts ao norte do núcleo e redshifts ao sul do mesmo. Assumindo que estas estruturas tem origem em emissão do gás no plano da galáxia elas podem ser interpretadas como escoamentos de gás em direção ao núcleo (inflows). Estimamos uma taxa de inflow de ≈ 4 × 10−4M⊙ ano−1. Outra componente cinemática observada para o H2 foi interpretada como ejeção de gás do núcleo (outflows) com uma taxa de ≈ 4.66 × 10−4M⊙ ano−1.

In this thesis, I present the properties of IRAS 19306+1407 central source and its sur- rounding circumstellar envelope (CSE), from the analysis of near-infrared (near-IR) polarimetry and integral field spectroscopy (IFS), with supporting archived HST im- ages and sub-millimetre (sub-mm) photometry. This is supported by axi-symmetric light scattering (ALS), axi-symmetric radiative transfer (DART) and molecular hy-drogen (H2) shock models. The polarimetric images show that IRAS 19306+1407 has a dusty torus, which deviates from axisymmetry and exhibits a ‘twist’ feature. The DART and ALS modelling shows that the CSE consists of Oxygen-rich sub-micrometre dust grains, with a range in temperature from 130±30 to 40±20 K at the inner and outer radius, respectively, with inner and outer radii of 1.9±0.1×1014 and 2.7±0.1×1015 m. The CSE detached 400±10 years ago and the mass loss lasted 5700±160 years, assuming a constant asymptotic giant branch (AGB) outflow speed of 15 km s−1. The dust mass and total mass of the CSE is 8.9±5×10−4 and 1.8±1.0×10 −1 M⊙, assuming a gas-to-dust ratio of 200. The mass loss rate was 3.4±2.1×10−5 M⊙ year−1. The central source is consistent with a B1I-type star with a radius of 3.8 ± 0.6 R⊙, luminosity of 4500 ± 340 L⊙ at a distance of 2.7 ± 0.1 kpc. A purpose built idl package (fus) was developed and used in the SINFONI IFS data critical final reduction steps. It also produced emission line, kinematic and line ratio images. The IFS observations show that H2 is detected throughout the CSE, located in bright arcs and in the bipolar lobes. The velocity of the H2 is greatest at the end of the lobes. Brγ emission originates from, or close, to the central source – produced by a fast jump (J) shock or photo-ionised atomic gas. The 1-0 S(1)/2- 1 S(1) and 1-0 S(1)/3-2 S(3) ratios were used as a diagnostic and determined that H2 was excited by bow shaped shocks; however, these shock models could not wholly explain the observed rotational and vibrational temperatures. The CDR values were fitted by combining continuous (C) or J-bow shock and fluorescence models, with a contribution from the latter, observed throughout the CSE (5–77 per cent). The majority of shock can be described by a C-bow shock model with B = 0.02 to 1.28 mG. Shocks are predominately seen in the equatorial regions. Polarimetry and IFS highlight a ‘twist’ feature, which could be due to an episodic jet undergoing a recent change in the outflow direction. The sub-arcsecond IFS observations reveal a flocculent structure in the south- east bright arc, consisting of several clumps interpreted as a fast-wind eroding an equatorial torus, possibly forming H2 knots seen in (some) evolved planetary nebulae (PNe). My analysis has effectively constrained the following: spectral type, stellar radius, luminosity and distance, chemistry, dust grain properties, geometry, age, mass loss, excitation mechanism and evolutionary state of the post-AGB star and its surrounding CSE. I conclude that IRAS 19306+1407 is a post-AGB object on the verge becoming a PN.

Globular clusters are dense and massive star clusters that are an integral part of any major galaxy. Careful studies of their stars, a single cluster may contain several millions of them, have revealed that the ages of many globular clusters are comparable to the age of the Universe. These remarkable ages make them valuable probes for the exploration of structure formation in the early universe or the assembly of our own galaxy, the Milky Way. A topic of current research relates to the question whether globular clusters harbour massive black holes in their centres. These black holes would bridge the gap from stellar mass black holes, that represent the final stage in the evolution of massive stars, to supermassive ones that reside in the centres of galaxies. For this reason, they are referred to as intermediate-mass black holes. The most reliable method to detect and to weigh a black hole is to study the motion of stars inside its sphere of influence. The measurement of Doppler shifts via spectroscopy allows one to carry out such dynamical studies. However, spectroscopic observations in dense stellar fields such as Galactic globular clusters are challenging. As a consequence of diffraction processes in the atmosphere and the finite resolution of a telescope, observed stars have a finite width characterized by the point spread function (PSF), hence they appear blended in crowded stellar fields. Classical spectroscopy does not preserve any spatial information, therefore it is impossible to separate the spectra of blended stars and to measure their velocities. Yet methods have been developed to perform imaging spectroscopy. One of those methods is integral field spectroscopy. In the course of this work, the first systematic study on the potential of integral field spectroscopy in the analysis of dense stellar fields is carried out. To this aim, a method is developed to reconstruct the PSF from the observed data and to use this information to extract the stellar spectra. Based on dedicated simulations, predictions are made on the number of stellar spectra that can be extracted from a given data set and the quality of those spectra. Furthermore, the influence of uncertainties in the recovered PSF on the extracted spectra are quantified. The results clearly show that compared to traditional approaches, this method makes a significantly larger number of stars accessible to a spectroscopic analysis. This systematic study goes hand in hand with the development of a software package to automatize the individual steps of the data analysis. It is applied to data of three Galactic globular clusters, M3, M13, and M92. The data have been observed with the PMAS integral field spectrograph at the Calar Alto observatory with the aim to constrain the presence of intermediate-mass black holes in the centres of the clusters. The application of the new analysis method yields samples of about 80 stars per cluster. These are by far the largest spectroscopic samples that have so far been obtained in the centre of any of the three clusters. In the course of the further analysis, Jeans models are calculated for each cluster that predict the velocity dispersion based on an assumed mass distribution inside the cluster. The comparison to the observed velocities of the stars shows that in none of the three clusters, a massive black hole is required to explain the observed kinematics. Instead, the observations rule out any black hole in M13 with a mass higher than 13000 solar masses at the 99.7% level. For the other two clusters, this limit is at significantly lower masses, namely 2500 solar masses in M3 and 2000 solar masses in M92. In M92, it is possible to lower this limit even further by a combined analysis of the extracted stars and the unresolved stellar component. This component consists of the numerous stars in the cluster that appear unresolved in the integral field data. The final limit of 1300 solar masses is the lowest limit obtained so far for a massive globular cluster. / Kugelsternhaufen sind dichte, gravitativ gebundene Ansammlungen von teilweise mehreren Millionen Sternen, die ein fester Bestandteil jeder massiven Galaxie sind. Aus der Untersuchung der Kugelsternhaufen in der Milchstraße weiß man, dass das Alter von vielen dieser Objekte vergleichbar ist mit jenem des Universums. Dies macht sie zu wertvollen Forschungsobjekten, beispielsweise um die Entstehung der Milchstraße und die Strukturbildung im frühen Universum zu verstehen. Eine aktuelle wissenschaftliche Fragestellung befasst sich damit, ob Kugelsternhaufen massive schwarze Löcher beherbergen. Diese würden eine Brücke schlagen von den stellaren schwarzen Löchern, die durch den Kollaps massereicher Sterne entstehen, zu den supermassiven schwarzen Löchern, welche man in den Zentren massiver Galaxien beobachtet. Man bezeichnet sie daher auch als mittelschwere schwarze Löcher. Die sicherste Diagnostik, um schwarze Löcher zu detektieren und ihre Masse zu bestimmen ist, die Bewegung der Sterne innerhalb ihrer gravitativen Einflusssphäre zu vermessen. Spektroskopische Untersuchungen vermögen dies über die Dopplerverschiebung von Spektrallinien, sind jedoch in dichten stellaren Feldern wie Kugelsternhaufen schwierig. Aufgrund der Turbulenz in der Atmosphäre und dem endlichen Auflösungsvermögen des Teleskops erscheinen die Sterne in den Beobachtungen nicht punktförmig, sondern mit einer durch die Punktspreizfunktion (PSF) gegebenen Breite. In dichten stellaren Feldern führt dies dazu, dass die Sterne überlappen. Da klassische spektroskopische Verfahren nicht bildgebend sind, lassen sich die Beiträge der Einzelsterne zu einem beobachteten Spektrum nicht trennen und die Geschwindigkeiten der Sterne können nicht vermessen werden. Bildgebende spektroskopische Verfahren, wie etwa die Integralfeld-Spektroskopie, bieten jedoch die Möglichkeit, die PSF zu rekonstruieren und basierend darauf die Spektren überlappender Sterne zu trennen. Im Rahmen der vorgelegten Arbeit wird das Potential der Integralfeld-Spektroskopie in der Beobachtung dichter stellarer Felder zum ersten Mal systematisch analysiert. Hierzu wird eine Methodik entwickelt, die das Extrahieren von Einzelsternspektren über eine Rekonstruktion der PSF aus den vorhandenen Daten erlaubt. Anhand von Simulationen werden Voraussagen darüber gemacht, wie viele Sternspektren aus einem gegebenen Datensatz extrahiert werden können, welche Qualität diese Spektren haben und wie sich Ungenauigkeiten in der rekonstruierten PSF auf die Analyse auswirken. Es zeigt sich hierbei, dass die entwickelte Methodik die spektroskopische Analyse von deutlich mehr Sternen erlaubt als klassische Verfahren. Parallel zu dieser systematischen Studie erfolgt die Entwicklung einer dezidierten Analysesoftware, welche im zweiten Teil der Arbeit auf Daten von drei Kugelsternhaufen angewendet wird, die mit dem PMAS Integralfeld-Spektrographen am Calar Alto Observatorium aufgenommen wurden: M3, M13 und M92. Die Auswertung dieser Daten liefert Spektren für eine Stichprobe von ungefähr 80 Sternen pro Kugelsternhaufen, weit mehr als bisher im Zentrum eines der drei Haufen verfügbar waren. In der weiteren Analyse werden Jeans Modelle für jedes der drei Objekte gerechnet. Diese erlauben basierend auf einer angenommenen Massenverteilung innerhalb des Kugelsternhaufens eine Vorhersage der Geschwindigkeitsdispersion der Sterne. Der Vergleich mit den gemessenen Geschwindigkeiten zeigt, dass in keinem der drei Haufen ein schwarzes Loch benötigt wird, um die Dynamik der zentrumsnahen Sterne zu erklären. Im Gegenteil, die Beobachtungen können zu 99,7-prozentiger Sicherheit ausschließen, dass sich in M13 ein schwarzes Loch mit einer Masse größer 13000 Sonnenmassen befindet. In den anderen beiden Haufen liegt diese Grenze noch bei deutlich geringeren Massen, nämlich bei 2500 Sonnenmassen in M3 und 2000 Sonnenmassen in M92. In M92 ist es außerdem möglich, das Limit noch weiter herabzusetzen durch eine zusätzliche Analyse der unaufgelösten stellaren Komponente. Diese Komponente besteht aus dem integrierten Licht all jener Sterne, die zu schwach und zahlreich sind als dass sie aus den verfügbaren Daten einzeln extrahiert werden könnten. Das endgültige Limit von 1300 Sonnenmassen ist das geringste, welches bisher in einem massiven Kugelsternhaufen gemessen wurde.

Durant les deux dernières décennies, de nombreux efforts ont été apportés pour comprendre le processus de formation des structures de l'Univers jeune. Les avancées dans les technologies observationnelles atteintes aujourd'hui permettent d'observer des galaxies de plus en plus loin, y compris celles responsables de la réionisation cosmique qui a eu lors du premier milliard d'années de l'Univers. L'objectif principal de cette thèse a été de poser des contraintes sur la nature et l'abondance des sources responsables de la réionisation cosmique. Plus précisément, l'étude s'est portée sur les galaxies qui forment des étoiles et qui ont une émission Lyman-alpha (LAE) entre z ~ 3 et 6.7. Il est à noter que cette thèse a été réalisée au sein du consortium MUSE, tout nouvel instrument installé au VLT en janvier 2014 dont nous avons exploité les données du GTO. Ce travail de thèse a permis de confirmer la puissance inégalée de MUSE au niveau de la détection et de l'étude de sources extragalactiques faibles sans aucune présélection. Nous avons observé quatre amas-lentilles dont l'amplification de la lumière permet la détection de sources à faible luminosité, au prix d'une diminution du volume d'Univers observé. Nous nous sommes d'abord focalisés sur l'étude de l'amas de galaxies Abell 1689 afin de structurer une méthodologie applicable aux autres amas. En comparant la densité volumique des LAEs détectés aux différentes fonctions de luminosité (FdL) de la littérature, nous sommes arrivés à la conclusion suivante : la pente de la loi de puissance que décrit la fonction de Schechter pour la partie la plus faible est plus petite que alpha <= -1.5, ce qui signifie que le nombre de LAEs croît extrêment vite vers les faibles luminosités. Nous avons ensuite appliqué cette méthode aux autres amas de notre échantillon observés par MUSE. Les LAEs identifiés et mesurés dans ces amas sont typiquement dix fois plus faibles que ceux observés dans les champs vides (39 < log(Lya) < 42.5). Environ un tiers de ces LAEs n'a pas de contrepartie dans le continuum jusqu'à AB ~ 28 sur les images HST et n'aurait donc jamais été vu sur des relevés pointés. Le catalogue final contient plus de 150 LAEs, ce qui nous a permis d'étudier la contribution des objets les plus faibles, ainsi que l'évolution de la pente en fonction du redshift. Les résultats obtenus semblent confirmer que la pente alpha est proche de -2 pour l'ensemble des LAEs compris entre 2.9 < z < 6.7. On observe aussi une évolution de alpha, qui passe de -1.8 à -1.95 entre z ~ 3-4 et z ~ 5-7, un résultat original et non dépendant des données utilisées pour la partie brillante de la FdL. L'intégration de cette FdL permet ensuite de calculer la densité de photons ionisants émis par ces LAEs et de déterminer leur impact relatif sur la réionisation cosmique. A l'avenir, la profondeur de champ atteinte par les données du James Webb Space Telescope (JWST) va repousser la limite de détection de ces galaxies jusqu'à z ~ 8. L'utilisation de spectrographes dans le proche infrarouge comme MOSFIRE/Keck, KMOS/VLT ou le tout récent EMIR/GTC permettent déjà de confirmer des candidats à z >= 7. Cette thèse a apporté des nouvelles contraintes sur la partie faible de la FdL des LAEs pour un redshift allant jusqu'à z ~ 6, un début donc de ce que l'on va pouvoir faire dans les années à venir pour des redshifts de l'ordre de z ~ 7-8. / Significant efforts have been put for the past two decades to understand the formation process of structure in the early Universe. The recent technological advances in the observational field allow for observing galaxies further and further, even the ones responsible for the cosmic reionization which occurred during the first billion years of the Universe. The main goal of this thesis was to impose constraints on the nature and the abundance of the sources responsible of the cosmic reionization. More specifically, the study was focused on the star-forming galaxies that have a Lyman-alpha emission (LAE) between z ~ 3 and 6.7. This thesis has been conducted within the framework of the MUSE consortium, a brand new instrument installed on the VLT in January 2014, as part of the exploitation of the Guaranteed Time (GTO). This thesis work has enabled us to confirm the unrivalled power of MUSE concerning the detection and the study of weak extragalactic sources without any preselection. We have observed four lensing clusters which magnify the incident light and make it possible to detect faint sources, at the expense of a decrease of the volume of the observed Universe. At first we started with the study of the galaxy cluster Abell 1689 in order to build up a methodology we intend to apply on other galaxy clusters. By comparing the volume density of the detected LAEs to the luminosity functions (LF) coming from the literature, we have reached the following conclusion : the slope of the power law from the Schechter function is smaller than alpha <= -1.5, which means that the number of LAEs increases drastically towards the faint luminoities. Then we have applied the new-build method to the other galaxy clusters of our sample observed with MUSE. The LAEs we have detected and measured in this sample are roughly ten times fainter than the ones observed in blank fields thanks to the lensing effect (39 < log(Lya) < 42.5). About one third of them lacks a counterpart in the continuum up to AB ~ 28 on the HST images and couldn't have been seen on targeted surveys. The final catalog includes more than 150 LAEs, this amount has enabled us to study the contribution of the faintest ones and also the evolution of the slope according to the redshift. The results of this work seem to confirm that the slope alpha is close to -2 for all the 2.9 < z < 6.7 LAEs. Furthermore, one can notice the evolution of alpha from -1.8 to -1.95 between z ~ 3-4 and z ~ 5-7, an original result and irrespective of the data set used to complement the present sample towards the bright region of the LF. The integral of the LF allows for working out the ionizing photons density emitted by these LAEs and for determining their relative impact on the cosmic reionization. In the future, the depth of the James Webb Space Telescope (JWST) observations will improve the limits of galaxy detection, certainly up to z ~ 8. The use of near-IR spectrographs such as MOSFIRE/Keck, KMOS/VLT or the very recent EMIR/GTC already provides the confirmation of z >= 7 candidates. This thesis brought new constraints on the faint-end part of the LF of LAEs for a redshift up to z ~ 6, which represents a beginning with respect to all we can do in the coming years for redshifts up to z ~ 7-8.

Il y a près d’une décennie, l'utilisation des supernovae de type Ia comme indicateurs de distances a permis de découvrir l'expansion accélérée de l'univers. Les expériences de seconde génération ont augmenté de manière significative la taille et la qualité des échantillons à grand décalage vers le rouge. Cependant, l'échantillon de référence des supernovae à faible décalage vers le rouge, nécessaire à la cosmologie restait très restreint. The Nearby Supernova Factory a mesuré, à l'aide d'un instrument spectro-photométrique dédié (the Supernova Integral Field Sepctrograph), près de 200 nouvelles supernovae de type Ia. Ma thèse de doctorat a été effectuée à l'Institut de Physique Nucléaire de Lyon et au Lawrence Berkeley National Laboratory dans le cadre du projet international the Nearby Supernova Factory et a pour but l'étalonnage spectro-photométrique du spectrographe à champ intégral. Afin d'atteindre la précision souhaitée, une attention particulière a été apportée à plusieurs aspects majeurs de la procédure d'étalonnage, incluant: la détermination de la réponse impulsionnelle de l'instrument en vue de l'extraction 3D de sources ponctuelles, l'estimation de la qualité photométrique d'une nuit, l'obtention de l'extinction atmosphérique par nuit sur un domaine de longueur d'onde étendu, sa modélisation en terme de composantes physiques et sa variabilité au cours d'une nuit donnée. Une chaîne d'étalonnage multi-standard a été mis en \oe{}uvre utilisant approximativement 4000 observations spectro-photométriques d'étoiles standards. J'exposerai également à la fin de ce manuscrit les résultats scientifiques préliminaires de la collaboration SNfactory. / Ten years ago, type Ia supernovae used as distances indicators led to the discovery of the accelerating expansion of the universe. Today, a second generation of surveys has significantly increased the high-redshift type Ia supernovae sample. The low-redshift sample was however still limiting the cosmological analysis using SNe. In this framework, the Nearby Supernova Factory has followed 200 nearby type Ia supernovae using the dedicated Supernovae Integral Field Spectrograph with spectro-photometric capacities. My PhD thesis has been carried out at the Institut de Physique Nucléaire de Lyon and at the Lawrence Berkeley National Laboratoryin the framework of the international cosmological project SNfactory. In order to reach the design spectrophotometric accuracy, attention has been focused on several key aspects of the calibration procedure, including: determination of a dedicated point spread function for 3D point source extraction, estimating the nightly photometric quality, derivation of the nightly sky extinction over the extended optical domain, its modeling in terms of physical components and its variability within a given night. A full multi-standards calibration pipeline has been implemented using approximately 4000 observations of spectrophotometric standard stars taken throughout the night over nearly 500 individual nights. Preliminary scientific results of the whole SNfactory collaboration will be presented at the end of this thesis.

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