The dependence of UV extinction properties on dust environment
- Massa, Derck
- Dec 1, 1989.
- Physical Description:
- 1 electronic document
- Restrictions on Access:
- Unclassified, Unlimited, Publicly available.
- UV extinction data, derived from the Savage et al. (1985) ANS extinction catalog, are analyzed. The data include the normalized extinction at 1550 A, the strength of the 2175 A bump, and a crude estimate of the bump width. The results confirm the systematic increase of far-UV extinction with galactic altitude first uncovered by Kiszkurno-Koziej and Lequeux (1987) and verify that this effect is in fact a result of the dust being away from the plane, and not a generalized density dependence. It is also shown that the width of the 2175 A bump is systematically broader in denser regions (defined by large values of E(B-V) per Kpc), implying that a similar galactic altitude effect seen in this parameter may only be a reflection of the lower densities encountered away from the plane. The dependence of bump width upon bump strength is also examined. It is shown that a relationship between these two parameters is expected for certain models of the bump, but none is found. However, two factors which could be complicating a straightforward interpretation of the observations are identified and discussed.
- NASA Technical Reports Server (NTRS) Collection.
- Document ID: 19910005589.
Accession ID: 91N14902.
NASA, Ames Research Center, Interstellar Dust: Contributed Papers; p 21.
- No Copyright.
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