Chemical Evolution of Interstellar Dust — A Source of Prebiotic Material ?

The growth and chemical evolution of a typical interstellar dust grain are followed starting from average interstellar conditions to the dense cloud and contraction phase. Based on the theory of cometary accretion directly from cold interstellar dust it is shown that the bulk material of a primordial comet would consist mostly of an icy conglomerate of complex organic molecules and frozen radicals in which are imbedded approximately equal volumes (10% each) of small grains in two different sizes - one variety being the order of 0.05 μ and the other ~0.005 μ in size - consisting mostly of silicates

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The evolution of massive stars

Symposium - International Astronomical Union ◽

10.1017/s0074180900116833 ◽

1997 ◽

Vol 189 ◽

pp. 313-322 ◽

Cited By ~ 2

Author(s):

A. Maeder

Keyword(s):

Star Formation ◽

Uv Radiation ◽

Chemical Evolution ◽

Interstellar Dust ◽

Galactic Center ◽

Massive Stars ◽

Galactic Nuclei ◽

Proper Understanding ◽

Evolution Of Galaxies ◽

Distant Galaxies

Massive stars are the crossroads of many important astrophysical problems and thus a proper understanding of their evolution is very needed. They are the main sources of UV radiation, by heating the interstellar dust they produce the far-IR luminosities of galaxies. They are the precursors of Supernovae and also the main sources of nucleosynthesis. They are visible in distant galaxies and the recent observations of starbursts have shown their major role in the spectral and chemical evolution of galaxies. They begin to be observed in the galactic center and in regions of star formation around galactic nuclei.

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From Interstellar Dust to Comets to the Zodiacal Light

Symposium - International Astronomical Union ◽

10.1017/s0074180900067036 ◽

1980 ◽

Vol 90 ◽

pp. 343-350

Author(s):

J. M. Greenberg

Keyword(s):

Chemical Evolution ◽

Interstellar Dust ◽

Chemical Constituents ◽

Cometary Nucleus ◽

Zodiacal Light ◽

Metallic Inclusions ◽

Major Chemical

We consider the consequences of the assumption that the interplanetary particles which produce the zodiacal light have evolved from interstellar dust via comets. The chemical evolution of interstellar dust followed by the process of aggregation into the cometary nucleus and the subsequent ejection of cometary debris provide the basis for a model for the interplanetary particles. The scattering properties of these particles are reasonably consistent with current observations of the variation with elongation angle of the brightness and polarization of the zodiacal light. The major chemical constituents of the model are in the form of a matrix of volatile ices and complex nonvolatile molecules containing C, N and O in which are imbedded silicate and metallic inclusions.

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