Molecular Gas in Early-type Galaxies
- Author(s): Alatalo, Katherine Anne;
- Advisor(s): Heiles, Carl;
- et al.
This thesis explores the relationship between molecular gas and early-type galaxies (ETGs). Specifically, I explore how molecular gas behaves and is configured in a complete sample of morphologically selected elliptical and lenticular galaxies. I also highlight a case study where molecular gas is being expelled and its host is rapidly transitioning from starforming to quiescent.
I first present the Combined Array for Research for Millimeter Astronomy (CARMA) ATLAS3D CO imaging survey of 30 nearby CO-rich ETGs which, when combined with archival data, creates a catalog of 40 ETGs with available CO imaging within the context of the ATLAS3D survey. I examine the distribution of the morphologies of the molecular gas within these systems, and correlate them with other properties of the host galaxy, such as color and environment membership.
Following the molecular gas observations from both CARMA and the Submillimeter Array, I present molecular gas data for nearby field galaxy NGC 1266, which hosts a massive molecular outflow that is being driven by a central AGN. I present the properties and energetics associated with the system, and hypothesize about the driving mechanism. I compare the outflow in NGC 1266 to other known outflowing molecular systems and argue why NGC 1266 is unique.
From photometric observations from the Hubble Space Telescope as well as radio continuum observations from the Very Long Baseline Array, I present evidence that NGC 1266 is in a special phase of evolution, likely in a key part of the transition from being a blue starforming galaxy to a quiescent, red sequence galaxy. I argue that NGC 1266 should be considered a poststarburst galaxy, and explain why it is essential that searches for such transition objects find NGC 1266 analogs.