NAM2019
  • NAM2021
    • Contacts
  • Science
    • Science Programme
    • Plenary Talks
    • Parallel Sessions
    • Special Lunches/Discussion Sessions
    • Poster Session
    • NAM Community Session
  • Social
    • Presidential Address
    • Herschel Concert
    • RAS Awards Ceremony
    • Virtual Stonehenge Tour
  • Media
  • Public Engagement
    • Public engagement opportunities
    • Public talk
    • Writing Skyscapes
  • Venue
    • Code of Conduct
    • Accessing the conference
    • Gather.town
    • NAM2021 Slack
    • About Bath
  • Monday
  • Tuesday
  • Wednesday
  • Thursday
  • Friday
  • Posters
  • NAM2021
    • Contacts
  • Science
    • Science Programme
    • Plenary Talks
    • Parallel Sessions
    • Special Lunches/Discussion Sessions
    • Poster Session
    • NAM Community Session
  • Social
    • Presidential Address
    • Herschel Concert
    • RAS Awards Ceremony
    • Virtual Stonehenge Tour
  • Media
  • Public Engagement
    • Public engagement opportunities
    • Public talk
    • Writing Skyscapes
  • Venue
    • Code of Conduct
    • Accessing the conference
    • Gather.town
    • NAM2021 Slack
    • About Bath
  • Monday
  • Tuesday
  • Wednesday
  • Thursday
  • Friday
  • Posters

Tuesday

Schedule

id
date time
AM
09:53
Abstract
The refractory organic feedback of AGB stars to the ISM
Tuesday

Abstract details

id
The refractory organic feedback of AGB stars to the ISM
Date Submitted
2021-04-27 08:21:00
Marie
Van de Sande
KU Leuven
Beauty of Astronomical Dust
Contributed
M. Van de Sande (Institute of Astronomy, KU Leuven, Belgium), C. Walsh (School of Physics and Astronomy, University of Leeds, UK) and T. J. Millar (Astrophysics Research Centre, Queen’s University Belfast, UK)
AGB stars are the main contributors of pristine stellar dust to the interstellar medium (ISM), together with supernovae. Despite the importance of AGB dust to the chemical and physical evolution of interstellar dust, we do not know many of its crucial parameters, such as its grain-size distribution or even its exact composition. Our novel dust-gas chemical kinetics model of AGB outflows aims to help bridge this gap.

Interstellar dust is thought to be covered by a refractory organic mantle, produced by photoprocessing of interstellar ices during its evolution in the ISM. To investigate whether we can place the origin of the refractory mantle earlier in the dust’s evolution, in its “neonatal” AGB outflow phase, we included a new type of chemical reaction in our model: the photoprocessing of volatile complex ices into inert refractory organic material.

We estimated the refractory organic coverage of AGB outflows to the ISM for grids of carbon-rich and oxygen-rich outflows using observationally motivated parent species. While oxygen-rich dust is only negligibly covered, we find that carbon-rich dust has an average refractory coverage of 3-9%. In higher-density carbon-rich outflows, the coverage can be as high as 8-22%.

Photoprocessing of ices is hence a viable reaction in AGB outflows. Although the average refractory coverage AGB dust is too low to influence the ISM, it opens up questions on the refractory contribution of other dust-producing environments, in particular of supernovae. As for AGB outflows, we highlight the need for an improved understanding of the dynamics within AGB outflows, and of dust formation and evolution. A better understanding will be beneficial not only to AGB research, but also to the ISM.

NAM 2020 Logo AWRAS Logo

 

Bath University LogoUKRI STFC new

All attendees are expected to show respect and courtesy to other attendees and staff, and to adhere to the NAM Code of Conduct.

© 2022 Royal Astronomical Society

Login