摘要:

AbstractThe scattering of linearly polarized light in reflection nebulae is investigated. The distortion of the centrosymmetric pattern of the polarization vectors is calculated; it is found the linear polarization of the illuminating source in an optically thin nebula leads to an “elliptical” pattern. If foreward scattering angles are strongly favoured, for instance if the nebula is optically moderately thick and light from higher scattering angles is suppressed by extinction, arrays of nearly parallel polarizations may arise. In addition, circular polarisation will always occure. – Both pattern types have been observed in bipolar nebulae. We consider it probable that the investigated mechanism is, at least in part, responsible for these patterns. Detailed modelling of concrete cases is required to finally test whether the proposed mechanism is at

ISSN:0004-6337    

DOI:10.1002/asna.2113060502

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractThe origin of the noncircular pattern of the polarization vectors in the halo of scattered light around M82 is discussed anew. This pattern had been interpreted by SOLINGERand MARKERT(1975) to indicate a high contribution of the disk to the illumination of the halo, whereas the blue colour of the halo demands a significant contribution from a very blue illuminating source, the nucleus. The discussion of SOLINGERand MARKERThas been modified in two respects: 1. an extinction in the disk M82, distributed similar to the stars, is assumed; this strengthens the disk's ability to turn the polarization vectors parallel to itself, and 2. an original polarization of the nuclear light parallel to the galaxy's plane is assumed; this also causes a corresponding turning of the polarization vectors.The new estimate of the nuclear luminosity relative to the disk luminosity isLN/LD= 0.7 ± 0.3 compared to 0.05 by SOLINGERand MARKERT. This luminosity ratio enables the nucleus to determine the colour of the scattered light near the minor axis at low and medium distances from the centre

ISSN:0004-6337    

DOI:10.1002/asna.2113060503

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0004-6337    

DOI:10.1002/asna.2113060504

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0004-6337    

DOI:10.1002/asna.2113060506

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractA new version of the magnetic‐tape catalog of ABELLclusters of galaxies is used to obtain redshift estimators and to generate two samples of clusters. A procedure for searching for superclusters of galaxies is applied and the results are given in tabular and graphic form. For a lmited homogeneous sample (distance 60–275 Mpc, galactic latitudeB>35°), 12 multiplets, having member clusters with known redshifts, are found. It is shown that the spatial covariance function for rich clusters has the form ξ = (r0/r)γ withr0= 22.4 ± 1.8 Mpc and γ = 1.90 ± 0.25 for 3 Mpc

ISSN:0004-6337    

DOI:10.1002/asna.2113060507

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

摘要:

AbstractA survey of dwarf galaxies was carried out in the inner part of the IC 342 complex of galaxies, which is a subgroup of the M81 group, in an area of about 42 sq. degrees by means of Tautenburg 52‐in. Schmidt plates. Fifteen new dwarf candidates and four extended “cloudy” objects of very low surface brightness not yet classified were discovered. Coordinates, linear dimensions as well as remarks on the nature of the cloudy objects are given. A deeper analysis with 6‐meter plates is planned to study a part of the new objects more

ISSN:0004-6337    

DOI:10.1002/asna.2113060508

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY

ISSN:0004-6337    

DOI:10.1002/asna.2113060501

出版商:WILEY‐VCH Verlag    

年代:1985

数据来源: WILEY