Evolution of intermediate mass galaxies up to z~0.7 and studies of SNe Ia hosts

TL;DR

This paper investigates galaxy evolution up to z~0.7, introduces new methods for stellar mass estimation and sky extraction in spectra, and studies supernova host properties to understand their impact on cosmology.

Contribution

It presents novel techniques for stellar mass estimation in starburst galaxies, a new sky extraction method for fiber-fed spectra, and initial results on SNe Ia host galaxy properties.

Findings

Chemical enrichment insights inform galaxy formation scenarios.

New method improves stellar mass estimates in starburst galaxies.

Initial 2D maps of SNe Ia hosts reveal local galaxy properties.

Abstract

In the first part of this manuscript, I present the results on the properties of the interstellar medium and the stellar content of galaxies at z=0.6, from a representative sample of distant galaxies observed with the long slit spectrograph VLT/FORS2. This study has been realized in the framework of the ESO large program IMAGES "Intermediate MAss Galaxy Evolution Sequences", which aims to investigate the evolution of the main global properties of galaxies up to z~0.9. I discuss the implications of the observed chemical enrichment of the gas on the scenarios of galaxy formation. I also propose a new method to estimate reliable stellar masses in starburst galaxies using broadband photometry and their total star-formation rate. In a second part, I present a new method to extract, with high accuracy, the sky in spectra acquired with a fiber-fed instrument. I have developed this code in the Framework of the phase A of an instrument proposed for the E-ELT: OPTIMOS-EVE. This is a multi-fiber spectrograph able to observe at optical and infrared wavelengths simultaneously. In the third part, I show preliminary results from the CENTRA GEPI- survey at Calar Alto Observatory to study nearby galaxies, hosts of type Ia supernovae, using integral field spectroscopy. I present the first 2D maps of the gas and stellar populations of SNe Ia hosts. The results allow us to directly access the host properties in the immediate vicinity of the SNe Ia. This is a crucial step to investigate eventual correlations between galaxy properties and SNe Ia events and evolution, leading to systematic effects on the derivation of the cosmological parameters.