Carbon Monoxide Emissions in Middle Aged Debris Disks
Abstract
Circumstellar disks greater than 10 Myr old, referred to as debris disks, are expected to be gas poor. The original gas and dust in these disks is thought to be accreted onto the host stars, used up in the formation of planets and other bodies, or blown out of the disks via stellar radiation. However, recent ALMA observations at millimeter wavelengths have led to the detection of carbon monoxide (J=2-1) emission in a few debris disks, prompting further investigation.Using ALMA data, two separate models of gas genesis were tested against observations of the CO emissions in the disks around HIP 73145, HIP 76310, and HIP 84881 in the Upper Sco association. One of these models was built on the hypothesis that the gas in these debris disks is left over from stellar formation and has persisted over uncommonly long periods of time. The other model is built on the hypothesis that this gas is of secondary nature, produced by collisions between planetary bodies in the debris disks. Model emissions were calculated using the Line Modeling Engine (LIME) radiative transfer code and were compared with observational data to infer gas masses under both production scenarios. The implications of the masses of carbon monoxide in the disks suggested by each of the two models are discussed.
- Publication:
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American Astronomical Society Meeting Abstracts #229
- Pub Date:
- January 2017
- Bibcode:
- 2017AAS...22934506H