SWAG: Survey of Water and Ammonia in the Galactic Center

TL;DR

SWAG is a comprehensive interferometric survey of water and ammonia in the Galactic Center, providing detailed maps of molecular gas properties, star formation sites, and physical conditions in the Central Molecular Zone.

Contribution

It offers the first extensive multi-line interferometric dataset of the Galactic Center, enabling detailed analysis of gas temperature, density, and star formation activity.

Findings

Mapped molecular gas temperature, opacity, and formation temperature.

Identified sites of active star formation via water masers.

Provided detailed spectral and polarization data of the region.

Abstract

SWAG ("Survey of Water and Ammonia in the Galactic Center") is a multi-line interferometric survey toward the Center of the Milky Way conducted with the Australia Telescope Compact Array. The survey region spans the entire ~400pc Central Molecular Zone and comprises ~42 spectral lines at pc spatial and sub-km/s spectral resolution. In addition, we deeply map continuum intensity, spectral index, and polarization at the frequencies where synchrotron, free-free, and thermal dust sources emit. The observed spectral lines include many transitions of ammonia, which we use to construct maps of molecular gas temperature, opacity and gas formation temperature (see poster by Nico Krieger et al., this volume). Water masers pinpoint the sites of active star formation and other lines are good tracers for density, radiation field, shocks, and ionization. This extremely rich survey forms a perfect basis to construct maps of the physical parameters of the gas in this extreme environment.