# A luminous molecular gas pair beyond redshift 7

## TL;DR

This paper reports the first detection of molecular gas beyond redshift 7, revealing a system of interacting star-forming galaxies possibly hosting quasars, with new detections of CO lines, Lyman-alpha emission, and a potential water maser line.

## Contribution

First detection of molecular gas beyond redshift 7, demonstrating the presence of complex galaxy systems in the early universe.

## Key findings

- Detected CO(6-5) and CO(7-6) lines in galaxies at z>7
- Extended Lyman-alpha emission suggests interacting galaxies
- Possible detection of a 793.62-GHz water maser line

## Abstract

We report the first detection of molecular gas beyond redshift 7. The molecular gas is associated with the host galaxy of the quasar candidate PSO J145.5964+19.3565 and its companion PSO J145.5964+19.3565N separated by 20.7 kpc. The molecular gas of both companions is detected in two rotational transition lines of carbon monoxide, CO(6-5) and CO(7-6). We also detected the Lyman-alpha line of PSO J145.5964+19.3565 at z=7.08. The Lyman-alpha line emission is extended and might represent the blended emission of two different sources at a separation of <5 kpc. The detected CO and Lyman-alpha emission likely originate from a system of interacting star-forming galaxies that might host a quasar(s). We also report the detection of a new emission line from the system which is a possible 793.62-GHz water maser line.