J/A+A/641/A35ivo://CDS.VizieR/J/A+A/641/A35doi:10.26093/cds/vizier.36410035CDSSiebenmorgen R.Krelowski J.Smoker J.Galazutdinov G.Bagnulo S.2021-02-19T07:41:25Z2020-11-20T10:06:49ZCDS support team

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

cds-question@unistra.frdiffuse-molecular-cloudsextinctioninterstellar-mediumspectroscopyinterstellar-reddeningob-starsearly-type-starsThe precise characteristics of clouds and the nature of dust in the diffuse interstellar medium can only be extracted by inspecting the rare cases of single-cloud sightlines. In our nomenclature such objects are identified by interstellar lines, such as KI, that show at a resolving power of {lambda}{Delta}{lambda}~75000 one dominating Doppler component that accounts for more than half of the observed column density. We searched for such sightlines using high-resolution spectroscopy towards reddened OB stars for which far-UV extinction curves are known. We compiled a sample of 186 spectra, 100 of which were obtained specifically for this project with UVES. In our sample we identified 65 single-cloud sightlines, about half of which were previously unknown. We used the CH/CH^+^ line ratio of our targets to establish whether the sightlines are dominated by warm or cold clouds. We found that CN is detected in all cold (CH/CH^+^>1) clouds, but {is frequently absent} in warm clouds. We inspected the WISE (3-22um) observed emission morphology around our sightlines and excluded a circumstellar nature for the observed dust extinction. We found that most sightlines are dominated by cold clouds that are located far away from the heating source. For 132 stars, we derived the spectral type and the associated spectral type-luminosity distance. We also applied the interstellar CaII distance scale, and compared these two distance estimates with GAIA parallaxes. These distance estimates scatter by ~40%. By comparing spectral type-luminosity distances with those of GAIA, we detected a hidden dust component that amounts to a few mag of extinction for eight sightlines. This dark dust is populated by >~ 1um large grains and predominately appears in the field of the cold interstellar medium.2020A&A...641A..35Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/641/A35CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/641/A35https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/641/A35http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/641/A35https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/641/A35https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/641/A35http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/641/A35GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/641/A35/tablea3Results summaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/136] Star identifier in the papermeta.idintStarStar namemeta.id;meta.maincharRes[HR LR] Resolution, HR=high resolution, LR=low resolutionmeta.codecharClass[SM] Classification (1)meta.code.classcharEWCaK? Equivalent width of the CaII K line0.1pmspect.line.eqWidthintnullablee_EWCaK? Error in the equivalent width of the CaII K line0.1pmstat.errorintnullableEWCaH? Equivalent width of the CaII H line0.1pmspect.line.eqWidthintnullablee_EWCaH? Error in the equivalent width of the CaII H line0.1pmstat.errorintnullableDistCaII? Distance from CaIIpcpos.distanceintnullableE_DistCaII? Positive error in distance from CaIIpcstat.error;stat.maxintnullablee_DistCaII? Negative error in distance from CaIIpcstat.errorintnullableDistGAIA? Distance from GAIApcpos.distanceintnullableE_DistGAIA? Positive error in distance from GAIApcstat.error;stat.maxintnullablee_DistGAIA? Negative error in distance from GAIApcstat.errorintnullableSp/L? Spectral type to luminosity ratiosrc.spTypeintnullableClassCaII[SM-] Classification for CaK only (1)meta.code.classcharClassNaI[SM-] Classification for NaI only (1)meta.code.classcharClassKI[SM-] Classification for KI only (1)meta.code.classcharVHelHeliocentric velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatlogNKILog of KI column density (10^9^/cm^2^)log(1e+09cm**-2)phys.columnDensityinte_logNKIError in log of KI column density (10^9^/cm^2^)log(1e+09cm**-2)stat.errorintEWKI? Equivalent width in milli Angstroms for KI (7698 Angstroms)0.1nmspect.line.eqWidthfloatnullablee_EWKI? Error in equivalent width in milli Angstroms for KI (7698 Angstroms)0.1nmstat.errorfloatnullableEnvironClassification of cloud environment as cold (c) or warm (w) with or without CNI detectionmeta.code.classcharClassWise[abcde_] Infrared morphology of WISE (W4) imagemeta.code.classcharJ/A+A/641/A35/listspList of normalised spectra of our UVES from ESO programme 0102.C-0040(B) in the Heliocentric rest frame for several atomic and molecular linesLineLinemeta.id;spect.linecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharRvRatio of total-to-selective extinctionphys.absorption.gal;arith.ratiofloatlambda0Rest wavelength0.1nmem.wldoubleHV0Rest heliocentric velocitykm/sphys.veloc;pos.heliocentricdoublespShow the spectrummeta.ref.urlcharFileNameName of the spectrum file in subdirectory spmeta.id;meta.filecharJ/A+A/641/A35/listarAdditional spectra in the KI line for UVES data taken from the ESO archive, telluric correctedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharn_StarNotemeta.notecharObs.dateObservation datestime.epoch;obsnullablespShow the spectrummeta.ref.urlcharFileNameName of the spectrum file in subdirectory armeta.id;meta.filecharJ/A+A/641/A35/tablea1Study samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/136] Star identifier in the papermeta.idintStarStar namemeta.id;meta.maincharAltNameStar common namemeta.idcharVmagV band magnitudemagphot.mag;em.opt.VfloatE(B-V)E(B-V) reddeningmagphot.color.excessfloate_E(B-V)Error in E(B-V) reddeningmagstat.errorfloatAVExtinction in Vmagphys.absorptionfloate_AVError in extinction in Vmagstat.errorfloatRvTotal to selective extinctionkm/sphys.absorptionfloate_RvError in total to selective extinctionkm/sstat.errorfloatSpTypeLSpectral type from the literaturesrc.spTypecharr_SpTypeLReference for spectral type from the literature (1)meta.ref;pos.framecharSpTypeSpectral type from this papersrc.spTypecharInstInstrument usedinstr.setupcharr_InstReference for instrument used (2)meta.ref;pos.framecharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/641/A35/tablea2UVES and FEROS archive spectra fitting covering the KI lineSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/186] Star identifier in the papermeta.idintStarStar namemeta.id;meta.maincharType[S M Sa] Type (1)meta.codecharProgIDProgramme IDmeta.id;instr.obstycharHVHeliocentric velocity, fit parameters of the KI line profilekm/sspect.dopplerVeloc;pos.heliocentric;meta.modelledfloate_HVError in heliocentric velocitykm/sstat.errorfloatbb-value, fit parameters of the KI line profilekm/sspect.line.widthfloate_bError in b-valuekm/sstat.errorfloatlogNLog10 of the column density, fit parameters of the KI line profilelog(cm**-2)phys.columnDensityfloate_logNError in the column densitylog(cm**-2)stat.errorfloatFWHMInstrumental Full Width Half Maximumkm/sspect.line.widthfloatn_Star[*] Mote on Star (2)meta.notechar