The Origin of Elements Across Cosmic Time: Astro2020 Science White Paper

TL;DR

This white paper discusses the fundamental open questions about the origin of elements in the universe, highlighting recent advances and future tools that will address these issues across cosmic time.

Contribution

It outlines the key scientific questions and the upcoming observational and theoretical tools that will advance understanding of element formation in the next decade.

Findings

Identification of open questions in element origins.

Upcoming tools like chemical cartography and gravitational wave detection.

Anticipated improvements in models and measurements.

Abstract

The problem of the origin of the elements is a fundamental one in astronomy and one that has many open questions. Prominent examples include (1) the nature of Type Ia supernovae and the timescale of their contributions; (2) the observational identification of elements such as titanium and potassium with the $\alpha$-elements in conflict with core-collapse supernova predictions; (3) the number and relative importance of r-process sites; (4) the origin of carbon and nitrogen and the influence of mixing and mass loss in winds; and (5) the origin of the intermediate elements, such as Cu, Ge, As, and Se, that bridge the region between charged-particle and neutron-capture reactions. The next decade will bring to maturity many of the new tools that have recently made their mark, such as large-scale chemical cartography of the Milky Way and its satellites, the addition of astrometric and asteroseismic information, the detection and characterization of gravitational wave events, 3-D simulations of convection and model atmospheres, and improved laboratory measurements for transition probabilities and nuclear masses. All of these areas are key for continued improvement, and such improvement will benefit many areas of astrophysics.