The Effect of Methane, Ammonia, and Silicates on the 3.07-MICRON Ice Absorption in Interstellar Grains

Hunter, Charles E.; Donn, B.

doi:10.1086/151004

Cited by 6 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The composition of interstellar grains, on which the photoemission properties depend somewhat, is essentially unknown. There is weak evidence against the ice (Knacke, Cudaback, and Gaustad 1969;Hunter and Donn 1971), and certain absorption features of grains near stars (where grains probably are formed) can be identified with silicates (Woolf and Ney 1969;Gillett, Merrill, and Stein 1971). Based on the amount of material needed to explain interstellar optical extinction together with cosmic abundances, and on the substances that might be expected to condense in the atmospheres of cool stars, 1972ApJ...176..103W No.…”

Section: H) Composition Of Interstellar Grainsmentioning

confidence: 99%

Heating of Interstellar H i Clouds by Ultraviolet Photoelectron Emission from Grains

Watson¹

1972

ApJ

153

View full text Add to dashboard Cite

The physical processes and consequences of photoemission from interstellar grains in H i regions are investigated. For likely grain materials except ice, the photoemission is expected from laboratory data to be relatively efficient for photon energies of ^ 10-13.6 eV. It causes these interstellar grains to be positively charged in H i regions if the galactic ultraviolet flux is that indicated by recent observations. The ejected photoelectrons represent an energy input into interstellar H i clouds that is comparable to that from proposed fluxes of low energy cosmic rays or X-rays. Photoemission alone can maintain gas temperatures near 50° K in "standard" H i clouds. The exact value of the temperature depends on the grain density in the gas and the possible underabundance of carbon.

show abstract

Section: H) Composition Of Interstellar Grainsmentioning

confidence: 99%