Scientific requirements of ALMA, and its capabilities for key-projects: Extragalactic

TL;DR

This paper discusses ALMA's technical specifications driven by key scientific goals, emphasizing its capabilities for extragalactic research such as detecting spectral lines at high redshift and imaging with high resolution, exemplified by a large project on submm galaxies.

Contribution

It details ALMA's technical requirements aligned with primary science goals and proposes a large extragalactic project focusing on molecular line studies of submm galaxies.

Findings

ALMA can detect spectral lines from galaxies at z=3.

ALMA provides imaging at 0.1" resolution.

A large project on submm galaxies is feasible.

Abstract

The Atacama Large Millimeter Array (ALMA) consists of 64 antennas of 12m diameter that will initially observe in 4 frequency bands between 84 and 720 GHz with spatial resolutions down to 0.01" and velocity resolutions as fine as 0.05 km/s. These technical requirements are based on three primary science goals. We illustrate two of these requirements: (i) the ability to detect spectral line emission from a Milky-Way type galaxy at z=3, and (ii) the ability to provide precise images at an angular resolution of 0.1". Finally, we present a possible large extragalactic project with ALMA: molecular line studies of submm galaxies.