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Full-Text Articles in Physical Sciences and Mathematics
Interstellar Gas And Dust In The Young Cluster Ic 348, Theodore P. Snow, Margaret Murray Hanson, C Gregory Seab, Jon M. Saken
Interstellar Gas And Dust In The Young Cluster Ic 348, Theodore P. Snow, Margaret Murray Hanson, C Gregory Seab, Jon M. Saken
Physics Faculty Publications
We have completed a multiband absorption- and emission-line study of a star embedded in the young cluster IC 348, to determine the environmental effect of star formation on the interstellar medium (ISM) local to the region. The hottest and youngest star in IC 348 is BD+31°643, a B5 V star which samples the inner bright nebular region. The nearby star o Per, which lies only 8 to the north and is thought to lie beyond IC 348, samples the gas and dust which has not been processed by very recent star formation. We speculate that the ISM throughout the region …
On The System Of Diffuse Interstellar Bands At 5844 And 5850 Å, J Krelowski, Theodore P. Snow, J Papaj, C G. Seab, B Wszolek
On The System Of Diffuse Interstellar Bands At 5844 And 5850 Å, J Krelowski, Theodore P. Snow, J Papaj, C G. Seab, B Wszolek
Physics Faculty Publications
Two neighboring diffuse interstellar bands (DIBs) at 5844 and 5850 Å are shown to be of different origin. The presence or absence of the 5844 DIB is related to the ratio of the two prominent DIBs at 5780 and 5797 Å as well as to the nature of the ultraviolet extinction curve. The 5844 Å DIB is very sensitive to the extinction, being completely absent in cases where the far-UV extinction is low. This suggests that the carrier is destroyed by photons having energies above 11 or 12 eV. The 5850 Å DIB correlates very well with the well-studied DIB …
On The Size Distribution Of Newly Formed Grains In Red Supergiant Atmospheres, C Gregory Seab, Theodore P. Snow
On The Size Distribution Of Newly Formed Grains In Red Supergiant Atmospheres, C Gregory Seab, Theodore P. Snow
Physics Faculty Publications
Theoretical ultraviolet extinction curves have been calculated for comparison with observed curves for circumstellar dust in M supergiants. The theoretical curves assumed a silicate grain composition, because silicate grains are expected in the oxygen-rich environments that are observed. Calculations were performed with and without the inclusion of scattering into the beam, with largely similar results. A comparison of the computed curves with the observed ultraviolet extinction curve for circumstellar dust in Scorpii indicates that the size distribution of the circumstellar grains must cut off near 800 Å that is, there are few or no grains smaller than this. Our conclusion …
Predicting Peculiar Interstellar Extinction From Gaseous Abundances, Charles L. Joseph, Theodore P. Snow, C Gregory Seab
Predicting Peculiar Interstellar Extinction From Gaseous Abundances, Charles L. Joseph, Theodore P. Snow, C Gregory Seab
Physics Faculty Publications
Molecular and atomic abundances are examined for 19 lines of sight through dense clouds, each with a peculiar selective extinction curve. The interstellar clouds in the present study appear to fall into two distinct categories: CN-rich, with relatively small amounts of neutral iron, or CN-poor, with large amounts of neutral iron. Lines of sight, having a CN/(Fe i) abundance ratio about two (~ 0.3 dex) or greater, are found to have a shallow (2.57 ± 0.55 mag) 2175 Å feature relative to the underlying extinction, while the strength of the bump is 3.60 ± 0.36 for the other dense clouds …