J/A+A/709/A277ivo://CDS.VizieR/J/A+A/709/A277CDSSiebenmorgen R.Bagnulo S.Fanciullo L.Vannieuwenhuyse T.Guillet V.2026-05-25T11:37:00Z2026-05-25T12:34:18ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frpolarimetryinterstellar-mediumvisible-astronomyspectroscopyinfrared-astronomyOur understanding of dust in the diffuse interstellar medium remains incomplete with regard to the structure, composition, size distribution, and alignment properties of its grains. Joint observations of reddening, starlight polarisation spectra, and polarised dust emission for individual sightlines provide essential constraints on such properties. We study a far-UV selected sample of 96 reddening curves, for which optical linear polarisation spectra were obtained with FORS at the VLT as part of the Large Interstellar Polarisation Survey (LIPS). Starlight polarisation spectra for 60 stars are presented in this work. These data are combined with Gaia distance estimates and Planck thermal dust emission. A three-component dust model is made publicly available. It consists of nanoparticles, amorphous grains, and micrometre-sized dust agglomerates, varying axial ratios, porosities, sizes, element abundances, and alignment efficiencies to match the observations. The diversity of reddening and polarisation spectra is well reproduced by prolate grains with typical axial ratios of two, a porosity of 10%, and high alignment efficiencies. Such efficiencies can be achieved with radiative torque alignment theory (RAT), but not with imperfect Davis-Greenstein (IDG) alignment, except when adjusting the magnetic-field orientation to maximise the polarisation. Micrometre-sized dust contributes wavelength-independent grey extinction in the optical, accounts for about one-third of the visual extinction, and carries one-third of the dust mass. A follow-up submillimetre survey with high-resolution polarimetry will further constrain grain shapes and alignment physics.2026A&A...709A.277Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/709/A277CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/608/A146 : Southern Hemisphere ISM FORS2 spectropolarimetryhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/709/A277https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/709/A277http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/709/A277https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/709/A277https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/709/A277http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/709/A277GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/709/A277/list (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/709/A277/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/709/A277/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/709/A277/list?GETtext/xml+votable180.050000true237.7783333-55.05552780.0055555555555555566/1060 1558 12972 14368 21428 21439 21638 21644 22246 22249 22805 22854 23284 23410 23647 24230 28759 28796 28890-28891 28900 28915 29040 29089 29095 29138 29792 30359 30709 31133 31169 37128 37145 37897 37932 38016 38018 38024 38074 39243 39252 39272 39334 39804 39807 41129 41134 41650-41651 41660 41812 41862 42236 42394 42417 42947 42959 42977 42985 44366 45105https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/709/A277?format=asciiOpticalInfrareddefaultJ/A+A/709/A277/listList of studied starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRAJ2000Simbad right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Simbad declination (J2000)pos.eq.dec;meta.mainObs.dateObservation datetime.epoch;obsnullableGrimGrims (300I or 300V)meta.id;instrcharFileNameName of the tar file with spectra in subdirectory spmeta.id;meta.filecharSimbadNameSimbad column added by the CDSmeta.idcharnullable