Molecular Disk Properties in Early-Type Galaxies

TL;DR

This study uses simulations to show that molecular disks commonly form in early-type galaxies after gas-rich mergers, aligning with observations and aiding future detection efforts.

Contribution

It demonstrates that molecular disk formation is a frequent outcome of gas-rich galaxy mergers, supported by simulated and observational comparisons.

Findings

Molecular disks form in most simulated gas-rich mergers.

Simulated disk properties agree with recent observations.

Discusses how these disks can be detected in future studies.

Abstract

We study the simulated CO emission from elliptical galaxies formed in the mergers of gas-rich disk galaxies. The cold gas not consumed in the merger-driven starburst quickly resettles into a disk-like configuration. By analyzing a variety of arbitrary merger orbits that produce a range of fast to slow-rotating remnants, we find that molecular disk formation is a fairly common consequence of gas-rich galaxy mergers. Hence, if a molecular disk is observed in an early-type merger remnant, it is likely the result of a "wet merger" rather than a "dry merger". We compare the physical properties from our simulated disks (e.g. size and mass) and find reasonably good agreement with recent observations. Finally, we discuss the detectability of these disks as an aid to future observations.