The first results from the Herschel-HIFI mission

TL;DR

This paper summarizes initial scientific results from the Herschel-HIFI mission, revealing new insights into the structure of the interstellar medium, star formation, and solar system objects using far-infrared and submillimeter observations.

Contribution

It provides the first comprehensive overview of Herschel-HIFI findings, highlighting the complex, mixed structure of interstellar gas and matter exchange in the solar system.

Findings

Interstellar medium has a mixed, not layered, structure.

Significant matter exchange occurs between comets, asteroids, and planets.

HIFI data advances understanding of star and planet formation.

Abstract

This paper contains a summary of the results from the first years of observations with the HIFI instrument onboard ESA's Herschel space observatory. The paper starts by outlining the goals and possibilities of far-infrared and submillimeter astronomy, the limitations of the Earth's atmosphere, and the scientific scope of the Herschel-HIFI mission. The presentation of science results from the mission follows the life cycle of gas in galaxies as grouped into five themes: Structure of the interstellar medium, First steps in interstellar chemistry, Formation of stars and planets, Solar system results and Evolved stellar envelopes. The HIFI observations paint a picture where the interstellar medium in galaxies has a mixed, rather than a layered structure; the same conclusion may hold for protoplanetary disks. In addition, the HIFI data show that exchange of matter between comets and asteroids with planets and moons plays a large role. The paper concludes with an outlook to future instrumentation in the far-infrared and submillimeter wavelength ranges.