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Local intersteller medium
Radio, IR, optical, UV, and X-ray observations of the local interstellarmedium (LISM) are reviewed, confirming the previous suggestion that thesun is located near an edge of a giant cavern with a radius of about 180pc whose center coincides with the Sco-Cen associated center. It issuggested that the bright spots of soft X-rays observed near thegalactic poles are produced by an interaction of stellar winds with theouter edge of the local cloud near the ends of Tinbergen's (1982) 'patchof polarization'. Results indicate that the main source of ionization ofextended H II regions of low density in the LISM is the Lyman continuumradiation from Sco-Cen stars.
| On the distribution of interstellar matter around the sun
Available data on interstellar line or EUV continuum absorptionattributable to the local (r equal to or less than 100 pc) interstellarmedium are presented and analyzed as a whole for clues leading to adeeper understanding of the spatial distribution and physical propertiesof this material. By using these data in conjunction with upper limitsprovided by polarization and color excess surveys and relatingeverything to the neutral-hydrogen column density, it is shown that thedata are consistent with a simple model that assumes the relativelypervasive presence of a tenuous (nH = 0.07 per cu cm), possibly warm (T= 1,000-10,000 K) gas extending uniformly out to considerable distancesfrom the sun in most directions. The only region manifestly clear ofthis material lies in the 200 deg to 270 deg galactic longitude range inboth high and low latitudes. Strong density discontinuities are clearlyobservable at r approximately 100-150 pc in the general directions ofthe Sco-Cen and Per associations and a weaker discontinuity much closerto the sun running along a ridge oriented parallel to the lineconnecting their centers. Beyond these fronts, the space density ofinterstellar matter must fall to very low values that extend out toseveral hundred parsecs or so from the sun. These results are notincompatible with H I, 21-cm, and soft X-ray all-sky surveys. Theimplication of these findings for the theory of the interstellar mediumand EUV visibility is briefly discussed.
| A Finding List of Early-Type Stars in Regions of Intermediate Galactic Latitude
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969ApJ...157..327U&db_key=AST
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