J/A+A/678/A148ivo://CDS.VizieR/J/A+A/678/A148CDSFarhang A.Smoker J.Cox N.L.J.Cami J.Linnartz H.van Loon J.T.,Cordiner M.A.Sarre P.J.Khosroshahi H.G.Ehrenfreund P.Foing B.H.,Kaper L.Laverick M.2024-11-28T16:24:11Z2023-10-17T15:47:22ZCDS support team

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

cds-question@unistra.frdiffuse-molecular-cloudsinterstellar-mediumproper-motionsspectroscopyvisible-astronomyearly-type-starsInterstellar absorption observed toward stellar targets changes slowly over long timescales, mainly due to the proper motion of the background target relative to the intervening clouds, such that over time, different parts of the intervening cloud are probed. On longer timescales, the slowly changing physical and chemical conditions in the cloud can also cause variation. Detecting such time variations thus provides an opportunity to study cloud structure. We searched for systematic variations in the absorption profiles of the diffuse interstellar bands (DIBs) and interstellar atomic and molecular lines by comparing the high-quality data set from the recent ESO diffuse interstellar bands large exploration survey (EDIBLES) to older archival observations, bridging typical timescales of ~10 years with a maximum timescale of 22 years. For 64 EDIBLES targets, we found adequate archival observations. We selected 31 strong DIBs, 7 atomic and 5 molecular lines to focus our search on. We carefully considered various systematic effects and used a robust Bayesian quantitative test to establish which of these absorption features could display significant variations. While systematic effects greatly complicate our search, we find evidence for variations in the profiles of the {lambda}{lambda}4727 and 5780 DIBs in a few sightlines. Toward HD 167264, we find a new CaI cloud component that appears and becomes stronger after 2008. The same sightline furthermore displays marginal, but systematic changes in the column densities of the atomic lines originating from the main cloud component in the sightline. Similar variations are seen toward HD 147933. Our high-quality spectroscopic observations in combination with archival data show that it is possible to probe interstellar time variations on time scales of typically a decade. Despite the fact that systematic uncertainties as well as the generally somewhat lower quality of older data complicate matters, we can conclude that time variations can be made visible, both in atomic lines and DIB profiles for a few targets, but that generally, these features are stable along many lines of sight. We present this study as an archival baseline for future comparisons, bridging longer periods.2023A&A...678A.148Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A148CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/606/A76 : The ESO DIBs Large Exploration Survey (Cox+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/678/A148https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/678/A148http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/678/A148https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/678/A148https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/678/A148http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/678/A148GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/678/A148/tablea1 (Studied targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A148/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A148/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A148/tablea1?GETtext/xml+votable180.050000true55.5933.960.0055555555555555566/405 1060 1198 1539 1550 12972 14356 19009 21439 21635 21647 21656 22845 22854 22884 23281 23717 23979 24340 24370 24463 29089 29162 29460 29463 29513 29522 29621 29876 29893 30718 30818 31756 37231 37593 37754 37877 37893 37930 38016 38024 39281 39327 39907 41510 41598 41630 41653 41750 42214 42236 42368 42394 42408 42416 42483 42791 42981 42994 43024 43040 45105https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/678/A148?format=asciiOpticaldefaultJ/A+A/678/A148/tablea1Studied targetsSpTypeSpectral typesrc.spTypecharInstInstrumentmeta.id;instrcharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name HD numbermeta.id;meta.mainintn_Target[+] Note on Target (1)meta.notecharE(B-V)Reddeningmagphot.color.excessfloatvISMISM reference frame velocitykm/sphys.veloc;pos.framefloatvsini? Rotational velocitykm/sphys.veloc.rotatintnullabler_vsini? Reference for vsini (2)meta.refintnullableRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainDistDistance to targetpcpos.distanceintpmOveral proper motionmas/yrpos.pmfloatObsObservation datetime.epoch;obsTravDist? Transversed distanceauphys.velocfloatnullableJ/A+A/678/A148/tableb1The dib fit resultsDate2Last epochtime.epochEW1Equivalent width for the first epoch0.1pmspect.line.eqWidthinte_EW1Error on Equivalent width for the epoch 10.1pmstat.errorintEW2Equivalent width for the second epoch0.1pmspect.line.eqWidthinte_EW2Error on Equivalent width for the epoch 20.1pmstat.errorintChi2baseChi square for the base modelstat.fit.chi2floatChi2gaussChi square for the Gauss modelstat.fit.chi2floatBICbaseBayesian Information Criterion (BIC) for the basestat.fit.chi2intBICgaussBayesian Information Criterion (BIC) for the Gaussstat.fit.chi2intdeltaBIC? BIC differencestat.fit.paramintnullableCommentSource of variation (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetHD number of the targetmeta.id;meta.mainintDIBDIB name0.1nmmeta.id;spect.lineintDate1First epochtime.epochJ/A+A/678/A148/tablec1The atomic line fits resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name HD numbermeta.id;meta.mainintAtomIon namephys.atmol.elementcharDate1First epoch (yyyymmdd)time.epochvel1Component velocity for the first epochkm/sphys.velocfloate_vel1Component velocity uncertaintykm/sstat.errorfloatlogN1Column density for the first epochcm**-2phys.columnDensityfloate_logN1Column density uncertaintycm**-2stat.errorfloatbeff1Doppler broadening for the first epochkm/sspect.line.broadfloate_beff1Doppler broadening uncertaintykm/sstat.errorfloatDate2Second epoch (yyyymmdd)time.epochvel2Component velocity for the second epochkm/sphys.velocfloate_vel2Component velocity uncertaintykm/sstat.errorfloatlogN2Column density for the second epochcm**-2phys.columnDensityfloate_logN2Column density uncertaintycm**-2stat.errorfloatbeff2Doppler broadening for the second epochkm/sspect.line.broadfloate_beff2Doppler broadening uncertaintykm/sstat.errorfloat