Posted under Colloquium

  1. Star formation quenching in cluster galaxies from integrated and spatially resolved spectra

    Abstract

    The distribution of galaxy properties such as colors, morphologies, and star formation rates is broadly bimodal, with early type galaxies being statistically red and quiescent, and late type galaxies being blue and actively star forming. When, why and how galaxies become passive is a crucial question in modern astrophysics, and might be related to both the galaxy intrinsic properties, and to the environment in which galaxies live. In particular, the cluster/denser environments are particularly efficient in quenching the star formation and therefore represent an ideal place where investigating galaxy properties. I will present the results that we obtained by studying a large sample of low-redshift clusters for which we have been able to characterize the different populations of galaxies on their way to become passive. I will also report on the Eso GASP Large Program, that is devoted to the study of a sample of cluster and field galaxies that show signatures of gas stripping at various degrees. GASP makes use of the MUSE IFU spectrograph at VLT, and has already observed ~50% of its targets. I will show the results that we have obtained so far for jellyfish galaxies, and I will briefly report on the emerging connection between jellyfish galaxies and AGN activity in cluster galaxies.

    astro.physics.unimelb.edu.au/2017/08/04/dr-_alessia_moretti-html

  2. HI and metal absorption lines during the Epoch of Reionization

    Abstract

    The distribution of galaxy properties such as colors, morphologies, and star formation rates is broadly bimodal, with early type galaxies being statistically red and quiescent, and late type galaxies being blue and actively star forming. When, why and how galaxies become passive is a crucial question in modern astrophysics, and might be related to both the galaxy intrinsic properties, and to the environment in which galaxies live. In particular, the cluster/denser environments are particularly efficient in quenching the star formation and therefore represent an ideal place where investigating galaxy properties. I will present the results that we obtained by studying a large sample of low-redshift clusters for which we have been able to characterize the different populations of galaxies on their way to become passive. I will also report on the Eso GASP Large Program, that is devoted to the study of a sample of cluster and field galaxies that show signatures of gas stripping at various degrees. GASP makes use of the MUSE IFU spectrograph at VLT, and has already observed ~50% of its targets. I will show the results that we have obtained so far for jellyfish galaxies, and I will briefly report on the emerging connection between jellyfish galaxies and AGN activity in cluster galaxies.

    astro.physics.unimelb.edu.au/2017/08/04/luz_angela-html