A new view on the ISM of galaxies: far-infrared and submillimetre spectroscopy with Herschel

TL;DR

This paper reviews the importance of FIR/submm spectroscopy in studying galaxy interstellar media, highlighting Herschel's unique capabilities and key scientific results from its mission and prior ISO observations.

Contribution

It presents a new perspective on FIR/submm spectroscopy of galaxies, emphasizing Herschel's role and potential in advancing ISM studies.

Findings

Herschel covers the entire FIR/submm range for the first time.

FIR spectroscopy reveals key diagnostics of neutral, ionized, and molecular ISM.

Herschel's data significantly enhance understanding of galaxy ISM properties.

Abstract

The FIR/submm window is amongst the least explored spectral regions of the electromagnetic spectrum. It is, however, a key to study the general properties of the interstellar medium of galaxies, as it contains important spectral line diagnostics from the neutral, ionized and molecular ISM. The Herschel Space Observatory, successfully launched on 14 May 2009, is the first observatory to cover the entire FIR/submm range between 57 and 672 mum. We discuss the main results from the ISO era on FIR spectroscopy of galaxies and the enormous science potential of the Herschel mission through a presentation of its spectroscopic extragalactic key programs.