LABOCA and MAMBO-2 imaging of the dust ring of the Sombrero galaxy (NGC 4594)

TL;DR

This study used submillimetre and millimetre observations to detect and analyze the dust ring of the Sombrero galaxy, providing new insights into its dust properties and mass.

Contribution

First detection of the Sombrero galaxy's dust ring at submillimetre and millimetre wavelengths with detailed modeling of its dust characteristics.

Findings

Dust ring radius matches optical and gas studies

Dust temperature is approximately 18.4 K

Dust mass is estimated at 1.6×10^7 solar masses

Abstract

The Sombrero galaxy (NGC 4594) is an Sa galaxy with a symmetric dust ring. We have used the Large APEX BOlometer CAmera (LABOCA) at 870 micron and the MAx-Planck Millimeter BOlometer (MAMBO-2) at 1.2 mm to detect the dust ring for the first time at submillimetre and millimetre wavelengths. We have constructed a model of the galaxy to separate the active galactic nucleus (AGN) and dust ring components. The ring radius at both 870 micron and 1.2 mm agrees well with the radius determined from optical absorption and atomic gas studies. The spectral energy distribution of the ring is well fitted by a single grey-body with dust emissivity index beta=2 and a dust temperature T_d=18.4 K. The dust mass of the ring is found to be 1.6\pm0.2x10^7Msun which, for a Galactic gas-to-dust ratio, implies a gas mass that is consistent with measurements from the literature.