Star formation across cosmic time with the PHIBSS programs

by Jonathan Freundlich

at Astrophysics and Cosmology Seminar

Wed, 28 Jun 2017, 11:15
Physics building (#54) room 207

Abstract

Star formation in the Universe experienced a peak ten billion years ago and a subsequent drop by an order of magnitude As stars are formed within giant molecular clouds it is crucial to probe molecular gas reservoirs to understand the cosmic evolution of the star formation rate The PHIBSS and PHIBSS2 programs at the IRAM Plateau de Bure NOEMA interferometer survey the molecular gas properties of galaxies on and around the main sequence where most of star formation occurs While the first PHIBSS program uncovered large molecular gas fractions at high redshift hence showing that the winding down of star formation was mostly driven by the diminishing cold gas reservoirs it also hinted at a slight increase of the star formation efficiency near the peak epoch of star formation The ongoing PHIBSS2 legacy program significantly extends the sample of molecular gas measurements within main sequence galaxies at different redshifts and systematically explores the dependence of the gas fraction and the depletion time with redshift stellar mass offset from the main sequence and morphology It notably establishes robust scaling relations encompassing these dependencies which should guide theoretical models of galaxy formation and evolution

Created on 22-06-2017 by Bar Lev, Yevgeny (ybarlev)
Updaded on 22-06-2017 by Bar Lev, Yevgeny (ybarlev)