Interstellar Dust: Physical ProcessesDust is formed in stellar environments, and destroyed by sputtering, shattering and vaporization in shock waves due to cloud-cloud collisions and supernova blast waves. Dust is also destroyed during star formation. We review the dust formation and destruction balance. The calculated destruction time-scale is less than or equal to one billion years and the star dust injection time-scale is approx. 2.5 billion years. Hence, the fractions of elemental carbon and silicon locked up in stardust are less than 0.3 and less than 0.15, respectively. An efficient ISM dust formation route is therefore implied. In particular, in dense clouds dust grows; through the processes of coagulation and the accretion of gas phase molecules e.g. H20, CO, CH4. These icy materials may then be photoprocessed to refractory materials in more diffuse regions. The resulting carbonaceous grain mantle may actually be the glue that holds the coagulated grains together.
Document ID
19970003297
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Jones, A. P. (NASA Ames Research Center Moffett Field,CA United States)
Tielens, A. G. G. M. (NASA Ames Research Center Moffett Field,CA United States)
Date Acquired
August 17, 2013
Publication Date
January 1, 1993
Publication Information
Publication: Proceedings of the 28th Rencontre de Moriond