Where is Population II?

Abstract

The use of roman numerals for stellar populations represents a classification approach to galaxy formation which is now well behind us. Nevertheless, the concept of a pristine generation of stars, followed by a protogalactic era, and finally the mainstream stellar population is a plausible starting point for testing our physical understanding of early star formation. This will be observationally driven as never before in the coming decade. In this paper, we search out observational tests of an idealized coeval and homogeneous distribution of population II stars. We examine the spatial distribution of quasars, globular clusters, and the integrated free electron density of the intergalactic medium, in order to test the assumption of homogeneity. Any $real$ inhomogeneity implies a population II that is not coeval.

for publication in PASA

References in corpus (5)

• The E-MOSAICS Project: simulating the formation and co-evolution of galaxies and their star cluster populations
• Paving the way for the JWST: witnessing globular cluster formation at z>3
• The Half Million Quasars (HMQ) Catalogue
• Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud: II. Relative ages and distances for six ancient globular clusters
• Observing patchy reionization with future CMB polarization experiments

Cited by in corpus (1)

• The intermediate age population of the Galactic halo