Oral Presentation

Galaxy quenching at high redshift revealed with multiwavelength observation

Author(s): Tomoko Suzuki (Kavli IPMU), Karl Glazebrook (Swinburne University of Technology), Corentin Schreiber (University of Oxford), Tadayuki Kodama (Tohoku University), and ZFOURGE team

Presenter: Tomoko Suzuki (Kavli IPMU)

The discovery in deep near-infrared (NIR) surveys of a population of massive quiescent galaxies at z > 3 has given rise to the question of how they came to be quenched so early in the history of the Universe. Star-formation history and molecular gas properties of quiescent galaxies at high redshift are keys to answering this question. In order to probe these physical quantities, multiwavelength observations are required. In this work, we conducted follow-up observations with ALMA of four quiescent galaxies at z = 3.5 - 4.0 found by the Fourstar Galaxy Evolution Survey (ZFOURGE). These galaxies were already spectroscopically confirmed. Furthermore, their star-formation histories were constrained by SED fitting with broadband photometry and NIR spectra. Our ALMA observations constrained the gas mass fraction of the quiescent galaxies at z > 3.5 to be < 20%. By combining with the star-formation histories inferred from SED fitting, we discuss how massive galaxies at z > 3.5 stopped their star formation.