arXiv subjects
Publications and source records attributed to Jayant Murthy.
Murthy et. al.(1994) discovered intense UV (1100 Å) emission from the directi on of the Coalsack Nebula. We have used their results in conjunction with a Mon te Carlo model for the scattering in the region to show that the scattering is from dust in the foreground of the Coalsack molecular cloud. We have constrained the albedo of the grains to 0.4 $\pm$ 0.1. This is the first determination of the albedo of dust in the diffuse ISM in the FUV.
We have observed intense diffuse radiation in the UV (1400 A - 2600 A) from three fields around M42 in Orion. Intensities of 20000 photons cm-2 s-1 sr-1 A-1 were observed to the east and west of M42 with 8000 photons cm-2 s-1 sr-1 A-1 south of the nebula. Enhanced emission, perhaps associated with a nearby complex of molecular clouds observed in CO, was detected in one of the fields. The IRAS 100 micron emission in that region is highly correlated with the UV intensity with a UV-IR ratio of 40 photons cm-2 s-1 sr-1 A-1 (MJy sr-1)-1. In the other two fields there was no structure in the diffuse emission nor was there any correlation with the IRAS emission.
We have examined 426 {\it Voyager} fields distributed across the sky for \ion{O}{6} ($λλ$ 1032/1038 Å) emission from the Galactic diffuse interstellar medium. No such emission was detected in any of our observed fields. Our most constraining limit was a 90% confidence upper limit of 2600 \phunit on the doublet emission in the direction (l, b) = (117\fdegree3, 50\fdegree6). Combining this with an absorption line measurement in nearly the same direction allows us to place an upper limit of 0.01 cm$^{-3}$ on the electron density of the hot gas in this direction. We have placed 90% confidence upper limits of less than or equal to 10,000 \phunit on the \ion{O}{6} emission in 16 of our 426 observations.