Abstract
We present results of a study of the Na i D interstellar absorption toward 17 binary and/or common proper-motion systems (including two triples). The stars range in spectral type from O6 to A5, lie at distances between 85 and 1200 pc, and have stellar separations between 480 and 29,000 AU. We compare the Na i absorption present in each of the two (or three) lines of sight and find that the line strength and/or profile varies for all 17 of the systems examined. We infer that small-scale structure in clouds containing Na i is ubiquitous and discuss the implications of that conclusion.
Original language | English (US) |
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Pages (from-to) | L127-L130 |
Journal | Astrophysical Journal |
Volume | 473 |
Issue number | 2 PART II |
DOIs | |
State | Published - 1996 |
Funding
1Visiting Astronomer, Kitt Peak National Observatory, National Optical Astronomy Observatories, operated by AURA, Inc., under contract with the National Science Foundation. It is a pleasure to thank Daryl Willmarth and the staff at KPNO for their expert assistance with the observations. We would also like to thank Dan Welty for discussions on the relationship between Na I and H I column densities. This work was supported in part by the National Science Foundation through grant AST93-15728 to Northwestern University.
Keywords
- ISM: clouds
- ISM: structure
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science