Ram pressure stripping is a well-known galactic quenching mechanism capable of removing star-forming gas from a galaxy as it falls into a group or cluster. However, prior to stripping, ram pressure can induce brief periods of enhanced star formation by compressing the gas on the leading side of an infalling galaxy. Studies of this phenomenon have focused primarily on a unique population of galaxies for which a stripped tail of gas opposing the direction of motion is visible, known as jellyfish galaxies. The role of this effect in galaxy evolution overall is currently unknown. This thesis investigates the importance of ram pressure-induced star formation across all infalling galaxies to generalize our understanding of the effect. We use several metrics to measure the star formation asymmetries of a large sample of group and cluster galaxies in the Sloan Digital Sky Survey using $u$-band imaging from the Canada-France Imaging Survey as a tracer for star formation rate. We find that the distributions of star formation asymmetries of satellite galaxies are indistinguishable from those of a control sample of isolated field galaxies. Subdividing the sample by host halo mass and time since infall, we still find no environmental dependence of ram pressure as an enhancer of star formation. We conclude that any statistical star formation enhancement is small for infalling galaxies, suggesting that this effect is either uncommon or short-lived. / Thesis / Master of Science (MSc)

Cette thèse présente la mesure des redshifts photométriques et des paramètres physiques dans le cadre des sondages de galaxies à grande échelle, ainsi que la contrainte qui peut en être extraite sur l'évolution des galaxies. Je montre notamment dans cette thèse dans quelle mesure la calibration photométrique affecte la précision des redshifts photométriques, afin de contraindre la stratégie photométrique à développer pour la mission Euclid.Afin de prendre en compte les problèmes inhérents à l'observation, les analyses ont été effectuée sur la base de données observées dont la configuration est proche de celle qui est attendue pour Euclid. Ces données combinent de nouvelles observations en proche-infrarouges conduites pour couvrir le sondage spectroscopique VIPERS et la photométrie du CFHTLS. Sur la base des conclusions tirées de cette analyse, j'ai produit le nouveau catalogue photométrique de VIPERS, ainsi que le catalogue de redshifts photométriques associé. J'ai finalement utilisée la même photométrie pour dériver les paramètres physiques d'environ 760 000 galaxies, réparties sur plus de 22 degrés carrés à une magnitude limite Ks(AB) < 22. J'ai ainsi pu étudier l'évolution de la fonction de masse stellaire entre les redshifts z = 0.2 et z = 1.5. Ceci a permis de montrer que les galaxies dont la masse stellaire est d'environ log(M/Msol) = 10.66 voient généralement leur formation stellaire stoppée en 2 à 4 milliards d'années, alors que les galaxies de faible masse (log(M/Msol) < 9.5) ne formant plus d'étoiles ont vu leur formation stellaire être arrêtée 5 à 10 fois plus rapidement (en environ 0.4 milliard d'années). / This thesis presents the measurement of the photometric redshifts and physical parameters in the framework of large scale surveys, and their constraint on galaxy evolution. The photometric redshift measurement allows us to study the entire photometric sample. For this reason, the weak lensing signal measurement used in the Euclid mission as a primary cosmological probe will rely on photometric redshift measurements. However, the method is strongly affected by the quality of the photometry. In particular, I show in this thesis how the photometric calibration impacts the photometric redshift precison, in order to constrain the photometric strategy to use in the Euclid mission.Aiming to take into account for observationnal problems, the analysis is done with observationnal data whose photometric configuration is close to the expected Euclid one. These data combine new near-infrared observations conduected to cover the VIPERS spectroscopic survey and the CFHTLS photometry.Using the conclusions of this analysis, I have producted the new photometric catalogue for VIPERS and the associated photometric redshift calalogue.Finally, I used the same photometry to compute the stellar masses of 760,000 galaxies covering 22 square degrees at the limiting magnitude Ks(AB) < 22. This enabled me to study the evolution of the stellar mass function between redshifts z= 0.2 and z = 1.5. We have then shown that the star formation of galaxies with stellar masses around log(M/Msol) = 10.66 is stopped in 2-4 Gyr, while in quiescent low-mass (log(M/Msol) < 9.5) galaxies, the star formation has been stopped 5-10 times faster (approximatelly in 0.4 Gyr).