Description
Understanding the interplay of dust in the galactic environment is crucial to gaining insight for the many chemical and physical processes a galaxy may undergo over its evolution. Dust grains are ever present in the ISM, shaping star formation via cooling gas clouds or absorbing and then re-emitting energy from its host in the sub-mm wavelengths. For most Early-Type galaxies (ETGs) ’red-and-dead’ was the typical assumption made. However, using the pristine resolution of the Herschel Space Observatory, studies have found that close to 50% of ETGs in our local universe contain some amount of dust and therefore molecular gas.
I will present our findings from the Herschel Almanac of Early-Type Galaxies (dubbed HEART). Born from the last days of Herschel – HEART is the largest targeted survey of Early-Types; Ellipticals and Lenticulars. By pulling from the original ATLAS$^{3D}$ sample of ETGs, this has allowed for a thorough exploration of the dust properties at our local epoch. With more than twice the number of targeted objects, across different environments and improved flux extraction techniques we can reduce biases seen in previous Herschel works quantifying each finding.
Our initial results suggest:
- A lack of environmental impact on the amount of dust a galaxy may contain when looking at Virgo vs. Non-Virgo objects and local galaxy density.
- Ellipticals seem to have slightly warmer dust temperatures when compared to lenticulars.
- Across the Hubble Sequence, dust-to-stellar-mass ratios seem to increase by a factor when moving across from ellipticals to spirals.
