Special Session SS6 3 – 6 April 2018 (TBD)

Dust formation by evolved stars and supernovae

Aims and scope

Since the existence of interstellar dust was first demonstrated nearly a century ago, the field has made enormous progress in modelling the dust properties and dust content of galaxies. However, the main sources responsible for producing interstellar dust still remain unknown. Along with the red supergiant phase of massive star evolution, AGB stars, the advanced evolutionary stage of low-intermediate mass stars (LIMS) have long been thought to be important sources of dust formation. Recently, Spitzer observations of the Magellanic clouds revealed that a few extreme AGB stars might be responsible for the majority of dust production by LIMS, but often are unable to account for the total dust content observed in these galaxies. With similar studies pending for a number of other Local Group galaxies, new GAIA distances will make it possible to perform similar studies on volume-limited Milky Way samples.

The first submm surveys of high-redshift galaxies about 20 years ago revealed large quantities of dust, and appear to require a different source of dust production. To solve this dust mass budget crisis at high redshifts, the production of dust in the early Universe has been proposed to be dominated by core-collapse supernovae (CCSNe). With the advent of submm/mm observatories (e.g., Herschel, ALMA, SOFIA), the first detections of the order of 0.2-1 Msun of dust in a handful of CCSNe have been reported in recent years. Other than acting as major dust factories, CCSNe appear to also be efficient dust destroyers through shock processing and so the net dust mass produced by CCSNe remains uncertain.

Currently, the regrowth of dust grains through accretion onto pre-existing grains in the interstellar medium has been advocated by some to be responsible for the formation of most of the interstellar dust in galaxies. The lack of viable chemical formation routes for grains to grow through metal accretion in the cold medium increases the need for a re-evaluation of the importance of stellar dust production sources (LIMS, CCSNe). We will also look ahead to the upcoming era of JWST, providing constraints on the dust production by LIMS and CCSNe beyond the Local Group.

During this special session, we aim to discuss the following open issues with experts in the field of dust formation in evolved stars and supernovae:

A. Dust condensation in low- and intermediate mass stars (LIMS):

  • 1: what type of LIMS dominate dust production?
  • 2: how do LIMS dust yields vary with metallicity, stellar rotation, etc. ?
B. Dust formation and destruction in core-collapse supernovae (CCSNe):
  • 3: how efficient do CCSNe form dust and how does SN dust formation evolve with time (instanteneous or gradual formation of SN dust)?
  • 4: how efficient are grains destroyed by the reverse shock?
C. Dust budgets in galaxies:
  • 5: what can be inferred from a comparison of interstellar dust properties with grains produced in LIMS/CCSNe?
  • 6: are LIMS+CCSNe capable of explaining the observed dust content in galaxies, or do we require grains to be regrown in the ISM?

Programme

Invited speakers

Scientific organisers

  • Ilse De Looze (University College London / Ghent University)
  • Olivia C. Jones (STScI)
  • Ambra Nanni (Universita di Padova)

Contact
Ilse De Looze (idelooze @ star.ucl.ac.uk)

Updated on Tue Sep 12 18:59:04 CEST 2017