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Session 120 - The Local Interstellar Medium.
Oral session, Thursday, January 18
Corte Real, Hilton

[120.05] Ultra-high-resolution observations of Interstellar NaI and CaII towards the high galactic latitude star HD 28497

M. S. Sahu (STScI), J. C. Blades (STScI), L. He (RPI), I. Crawford (UCL), M. J. Barlow (UCL), F. Diego (UCL)

We present high resolution (0.3 km s^-1) spectra, obtained with the Anglo-Australian Telescope (AAT) Ultra-High-Resolution Facility (UHRF), of interstellar NaI D_1, D_2 and CaII K absorption towards HD 28497. Numerous absorption components are evident in these spectra with four components showing s-resolved NaI hyperfine structure. If we assume the clouds represented by these components have no internal turbulent velocities, their temperatures range between 120 to 300K. These four clouds appear to be well correlated in velocity to known H_\alpha and HI filaments associated with the Orion-Eridanus bubble and the high galactic latitude molecular cloud MBM 20. Combining this new data with published Copernicus data in this sightline and data from previous HI, CO and H_\alpha surveys, a schematic representation of the possible components in the line of sight to HD 28497 is presented.

Program listing for Thursday