| Nearby galaxies provide ideal objects for studying the formation and evolution of galaxies.Galaxies are classified into different types according to their morphological or spectral characteristics.The optical emission lines of galaxies,star formation rates,scaling relations and their feedback processes play an important role in the study of galaxy formation and evolution.In recent years,with the rapid development of the integral field units technique,researchers have obtained a large sample containing spatially resolved information,which facilitates the study of the statistical properties of galaxy kinematics.In this thesis,we focus on the following questions based on the Ma NGA survey and Wi Fe S observations of the integral field units of nearby galaxies galaxies:(1)The impact of star formation feedback on galaxy kinematics.(2)The major mechanisms to drive turbulence in star-forming galaxies.(3)The host galaxy properties of Changing-look active galactic nuclei.This thesis begins with a briefly introduction to the classification of galaxies,optical emission lines,star formation rates,scaling relationships,and the feedback process of galaxies.At the same time,it gives a short introduction to the instrument for the two integral field units spectra used in this work.Then we analyze the intrinsic velocity dispersion properties of 648 star-forming galaxies observed by Ma NGA survey,to explore the relation of intrinsic gas velocity dispersions with star formation rates(SFRs),SFR surface densities(?SFR),stellar masses and stellar mass surface densities(?*).By combining with high z galaxies,we found that there is a good correlation between the velocity dispersion and the SFR as well as?SFR.But the correlation between the velocity dispersion and the stellar mass as well as?*is moderate.By comparing our results with predictions of theoretical models,we found that the energy feedback from star formation processes alone and the gravitational instability alone can not fully explain simultaneously the observed velocity-dispersion/SFR and velocity-dispersion/?SFRrelationships.The theoretical results show that two theoretical models,gravitational instability and star formation feedback,are proposed to explain the high gas velocity dispersion in high redshift galaxies.Using a representative sample selected from the x COLD GASS survey based on their star formation rates as well as gas fractions,we measured the intrinsic gas velocity dispersions,circular velocities and orbital periods trhough Wi Fe S integral field spectroscopic observations.Comparing the relation between the SFR,velocity dispersion,and gas fraction with predictions of these two theoretical models,we find that our results are most consistent with a model that includes both transport and feedback as drivers of turbulence in the interstellar medium.By contrast,a model where stellar feedback alone drives turbulence under-predicts the observed velocity dispersion in our galaxies.These observations therefore support the idea that gravitational instability is the dominant mechanism to drive turbulence in high redshift and high SFR galaxies.Finally,we find five new CL-AGNs through the Ma NGA survey.Taking advantage of spatial resolved information,we study the host galaxy properties of CL-AGNs.we find that all CL-AGNs reside in the star-forming main sequence,similar to NCL-AGNs;he 80%±16%of our CL-AGNs do possess pseudo-bulge features,and follow the overall NCL-AGNs-*relationship.The kinematic measurements indicate that they have similar distributions in the plane of angular momentum versus galaxy ellipticity.In addition,CL-AGNs favor more face-on than that of Type I NCL-AGNs.These results suggest that host galaxies could play a role in the CL-AGNs phenomenon. |
PDF Full Text Request