FUSE Observations of the HD Molecule toward HD 73882

TL;DR

This study utilizes FUSE observations to detect HD molecules in the interstellar medium, aiming to measure the HD/H2 ratio as a new method for estimating deuterium abundance in translucent clouds.

Contribution

First detection of HD toward HD 73882 using FUSE, demonstrating the potential of UV spectroscopy for deuterium abundance studies.

Findings

HD detected toward HD 73882

Potential to measure D/H ratio in interstellar clouds

Preliminary analysis indicates feasibility of the method

Abstract

The Lyman and Werner band systems of deuterated molecular hydrogen (HD) occur in the far UV range below 1200 A. The high sensitivity of the FUSE mission can give access, at moderate resolution, to hot stars shining through translucent clouds, in the hope of observing molecular cores in which deuterium is essentially in the form of HD. Thus, the measurement of the HD/H2 ratio may become a new powerful tool to evaluate the deuterium abundance, D/H, in the interstellar medium. We report here on the detection of HD toward the high extinction star HD 73882 [E(B-V)=0.72]. A preliminary analysis is presented.