Astronomy and Astrophysics – Astronomy
Scientific paper
May 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998mnras.296..414c&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Volume 296, Issue 2, pp. 414-418.
Astronomy and Astrophysics
Astronomy
12
Ism: Clouds, Dust, Extinction, Ultraviolet: Ism
Scientific paper
Interstellar dust containing carbon will necessarily have optical constants that respond to the local environment of the dust. This response may be sufficiently slow that the extinction produced by such dust may change on time-scales that are comparable to the likely cloud age. Therefore, interstellar extinction caused by carbon-containing dust should evolve in time. We explore this concept through a model of dust in which H-rich amorphous carbon is deposited on silicate substrates in the interstellar medium, and is annealed to form H-poor amorphous carbon. We find that, in this model, the interstellar extinction is sensitive to the gas density (which controls the rate of carbon depletion) and to the UV radiation field (which controls the annealing rate). In clouds typical of the diffuse interstellar medium, the initial extinction curve is fairly flat in the far UV, becomes similar to the `standard' interstellar curve after about 1-2 Myr, and remains similar to the standard curve for about a further 1 Myr. The curve then steepens in the far UV. The wide variations in the observed extinction may therefore simply reflect time-evolution of the dust properties.
Cecchi-Pestellini Cesare
Williams David. A.
No associations
LandOfFree
Evolving interstellar extinction does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evolving interstellar extinction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolving interstellar extinction will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1864491