Dust in Interstellar Clouds, Evolved Stars and Supernovae

Journal Article · Sun Sep 07 00:00:00 EDT 2008 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2996715· OSTI ID:21251196

Hartquist, T W; Van Loo, S; Caselli, P; Ashmore, I ^[1]

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1. School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)

Outflows of pre-main-sequence stars drive shocks into molecular material within 0.01-1 pc of the young stars. The shock-heated gas emits infrared lines of H{sub 2} and H{sub 2}O and millimeter and submillimeter lines of many species including CO, SiO, H{sub 2}S and HCO{sup +}. Dust grains are important charge carriers and play a large role in coupling the magnetic field and flow of neutral gas. Some understanding of the effects of the dust on the dynamics of oblique shocks began to emerge in the 1990s. However, detailed models of these shocks are required for the calculation of the grain sputtering contribution to gas phase abundances of species producing observed emissions. We are developing such models.Some of the molecular species introduced into the gas phase by sputtering in shocks or by thermally driven desorption in radiatively heated hot cores form on grain surfaces. Recently laboratory studies have begun to contribute to the understanding of surface reactions and thermally driven desorption important for the chemistry of star forming clouds.Dusty plasmas are prevalent in many evolved stars just as well as in star forming regions. Radiation pressure on dust plays a significant role in mass loss from some post-main-sequence stars. The mechanisms leading to the formation of carbonaceous dust in the stellar outflows are similar to those important for soot formation in flames. However, nucleation in oxygen-rich outflows is less well understood and remains a challenging research area.Dust is observed in supernova ejecta that have not passed through the reverse shocks that develop in the interaction of ejecta with ambient media. Dust is detected in high redshift galaxies that are sufficiently young that the only stars that could have produced the dust were so massive that they became supernovae. Consequently, the issue of the survival of dust in strong supernova shocks is of considerable interest.

• OSTI ID: 21251196
• Journal Information: AIP Conference Proceedings, Vol. 1041, Issue 1; Conference: 5. international conference on the physics of dusty plasmas, Ponta Degada, Azores (Portugal), 18-23 May 2008; Other Information: DOI: 10.1063/1.2996715; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
CARBON MONOXIDE
CHARGE CARRIERS
COSMIC DUST
DESORPTION
HYDROGEN
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MAIN SEQUENCE STARS
MOLECULAR IONS
OXYGEN
PHOTON EMISSION
PLASMA
RADIATION PRESSURE
RED SHIFT
SILICON OXIDES
SUPERNOVA REMNANTS
SUPERNOVAE
WATER