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arXiv · astro-ph/9710279

UV Absorption Lines from High-Velocity Gas in the Vela Supernova Remnant: New insights from STIS Echelle Observations of HD72089

Abstract

The star HD72089 is located behind the Vela supernova remnant and shows a complex array of high and low velocity interstellar absorption features arising from shocked clouds. A spectrum of this star was recorded over the wavelength range 1196.4 to 1397.2 Angstroms at a resolving power lambda/Delta lambda = 110,000 and signal-to-noise ratio of 32 by STIS on the Hubble Space Telescope. We have identified 7 narrow components of C I and have measured their relative populations in excited fine-structure levels. Broader features at heliocentric velocities ranging from -70 to +130 km/s are seen in C II, N I, O I, Si II, S II and Ni II. In the high-velocity components, the unusually low abundances of N I and O I, relative to S II and Si II, suggest that these elements may be preferentially ionized to higher stages by radiation from hot gas immediately behind the shock fronts.

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E. B. Jenkins, T. M. Tripp, E. L. Fitzpatrick, D. Lindler, A. C. Danks, T. L. Beck, C. W. Bowers, C. L. Joseph, M. E. Kaiser, R. A. Kimble, S. B. Kraemer, R. D. Robinson, J. G. Timothy, J. A. Valenti, B. E. Woodgate. 1997-10-24. UV Absorption Lines from High-Velocity Gas in the Vela Supernova Remnant: New insights from STIS Echelle Observations of HD72089. https://doi.org/10.1086/311114

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