Cold gas and dust
Clouds of dense, molecular gas fuel star formation within galaxies. Dust, which is also found in the interstellar medium, absorbs energy from starlight and re-radiates it at infrared wavelengths. We use the spectroscopic capabilities of ALMA to study carbon monoxide and neutral carbon spectral lines, which trace cold dense gas. ALMA continuum observations probe the Rayleigh-Jeans tail of the dust spectrum.
Image: The integrated flux map of a CO spectral line in a high-redshift cluster galaxy. This figure was shown in my 2016 AAS talk and is presented in my recent paper.