Chronos: A NIR spectroscopic galaxy survey. From the formation of galaxies to the peak of activity

TL;DR

Chronos aims to conduct the deepest NIR spectroscopic galaxy survey from space, capturing galaxy formation and evolution from the universe's first galaxies to peak activity, enabling detailed insights into cosmic history.

Contribution

This paper proposes a space-based NIR spectroscopic survey with unprecedented depth and coverage, focusing on galaxy formation and evolution from z=10 to z=1-3.

Findings

Deep NIR spectroscopic data from z=1 to 12 will be obtained.

The survey will reveal galaxy formation processes and quenching mechanisms.

It will provide insights into star formation, chemical enrichment, and dark matter connections.

Abstract

Chronos is our response to ESA's call for white papers to define the science for the future L2, L3 missions. Chronos targets the formation and evolution of galaxies, by collecting the deepest NIR spectroscopic data, from the formation of the first galaxies at z~10 to the peak of formation activity at z~1-3. The strong emission from the atmospheric background makes this type of survey impossible from a ground-based observatory. The spectra of galaxies represent the equivalent of a DNA fingerprint, containing information about the past history of star formation and chemical enrichment. The proposed survey will allow us to dissect the formation process of galaxies including the timescales of quenching triggered by star formation or AGN activity, the effect of environment, the role of infall/outflow processes, or the connection between the galaxies and their underlying dark matter haloes. To provide these data, the mission requires a 2.5m space telescope optimised for a campaign of very deep NIR spectroscopy. A combination of a high multiplex and very long integration times will result in the deepest, largest, high-quality spectroscopic dataset of galaxies from z=1 to 12, spanning the history of the Universe, from 400 million to 6 billion years after the big bang, i.e. covering the most active half of cosmic history.