J/A+A/672/A181ivo://CDS.VizieR/J/A+A/672/A181doi:10.26093/cds/vizier.36720181CDSSmoker J.V.Mueller A.Monreal Ibero A.Elyajouri M.Evans C.J.,Najarro F.Farhang A.Cox N.L.J.Minniti J.Smith K.T.Pritchard J.,Lallement R.Smette A.Boffin H.M.J.Cordiner M.Cami J.2023-08-31T07:39:45Z2023-04-19T08:52:58ZCDS support team

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

cds-question@unistra.frearly-type-starsemission-line-starschemical-abundancesinfrared-astronomyvisible-astronomyinterstellar-mediumThe diffuse interstellar bands (DIBs) are a set of hundreds of unidentified absorption features that appear almost ubiquitously throughout the interstellar medium. Most DIBs appear at optical wavelengths, but some are in the near-infrared. We aim to characterise near-infrared DIBs at high spectral resolving power towards multiple targets. We observed 76 early-type stars at a resolving power of 50000 (velocity resolution ~6km/s) and signal-to-noise ratios of several hundreds using the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES). These data allow us to investigate the DIBs around 1318.1, 1527.4, 1561.1, 1565.1, 1567.0, 1574.4, and 1624.2nm. We detected a total of six DIB features and 17 likely stellar features through comparisons with a model spectrum computed with cmfgen. Additionally, we measured equivalent widths of the DIBs at 1318.1 and 1527.4nm using observations with X-shooter towards ten very highly reddened (3.2<E(B-V)<6.5) Cepheid variable stars and towards four stars observed at low values of precipitable water vapour as well as by using other archive data. Results: We measured correlations (correlation coefficient r~0.73-0.96, depending on the subsample used) between DIB equivalent width and reddening for the DIBs at 1318.1, 1561.1, 1565.1, and 1567.0nm. Comparing the near-infrared DIBs with 50 of the strongest optical DIBs, we find correlations r>~0.8 between the 1318, 1527, 1561, 1565, and 1567nm and the optical DIBs 5705, 5780, 6203, 6283, and 6269{AA}. The 5797{AA}, DIB is less well correlated with the near-infrared DIBs. The DIB at 9632.1{AA}, which is likely C_60_^+^, is not well correlated with the 1318.1nm DIB. Partial correlation coefficients using E(B-V) as the covariate were also determined. For stars earlier than B2, the 1318.1nm DIB is affected by an emission line on its blue wing that is likely stellar in nature, although we cannot rule out an interstellar or circumstellar origin for this line caused by, for example, a DIB in emission. The 1318.1nm DIB also has an extended red wing. The line is reasonably well fitted by two Gaussian components, although neither the component equivalent width (EW) ratios nor the separation between components are obviously correlated with such indicators as {lambda}{lambda}5780/5797 and reddening. The EW at 1318nm correlates with HI with EW(1318nm)/E(B-V) decreasing with f(H_2_). Five pairs of stars within one arcmin of each other show very similar 1318.1~nm DIB profiles. Possible variation in the 1318.1nm feature is seen between HD 145501 and HD 145502 (separated by 41-arcsec, equivalent to 7200au) and HD 168607 and HD 168625 (separated by 67-arcsec, equivalent to 0.52pc on the plane of the sky). Seventeen sightlines have repeat CRIRES observations separated by six to 14 months, and two sightlines have repeat X-shooter observations separated by 9.9 years. No time variability was detected in the 1318.1nm DIB in the CRIRES data nor in the 5780.5, 5797.1, 1318.1, and 1527.4nm DIBs. Tentative time variation is observed in the C_60_^+^ DIBs at 9577 and 9632{AA}, towards HD 183143, although it is very close to the noise level and requires confirmation. The Near Infrared (NIR) DIBs observed occur more in more UV-irradiated regions than the 5797{AA}, DIB allowing the study of heavily reddened sightlines. Future searches for time variability in DIBs will require either higher quality data, larger intervals between epochs, or both.2023A&A...672A.181Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/672/A181CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/672/A181https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/672/A181http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/672/A181https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/672/A181https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/672/A181http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/672/A181GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/672/A181/tablea1 (Stellar sorted alphabetically and split into CRIRES and X-shooter subsections)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/672/A181/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/672/A181/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/672/A181/tablea1?GETtext/xml+votable180.050000true83.052517.05920.005555555555555556Cone search capability for table J/A+A/672/A181/tablee1 (Table of equivalent width measurements)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/672/A181/tablee1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/672/A181/tablee1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/672/A181/tablee1?GETtext/xml+votable180.050000true77.2865964-8.75408080.0055555555555555566/9502 21438 22615 23717 24139 28730 28803 28853 28891 29089 29098 29116 29154 29162 29190 29467 29504 29511 29513 29537 29809 30718 30722 37364 37900 37926 37930 38016 38018 38026 38073 38174 41100 41427 41610 41630-41631 41651 41685 41698 41813 41841 41843 42214 42221 42283 42377 42394 42405 42410 42439 42456 42458 42516 42932 42978 42994 43008 43019 43086 43368 43716 44378 44389 45615https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/672/A181?format=asciiOpticalInfrareddefaultJ/A+A/672/A181/tablea1Stellar sorted alphabetically and split into CRIRES and X-shooter subsections_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget name (1)meta.id;meta.maincharInstInstrument (2)meta.id;instrcharSpTypeSpectral type from Simbad (3)src.spTypecharSpType2Second spectral type from Simbadsrc.spTypecharGLON? Galactic longitude from Simbaddegpos.galactic.lonnullableGLAT? Galactic latitude from Simbaddegpos.galactic.latnullableBmag? B magnitude from Simbadmagphot.mag;em.opt.BfloatnullableVmag? V magnitude from Simbadmagphot.mag;em.opt.VfloatnullableHmag? H magnitude from Simbadmagphot.mag;em.IR.HfloatnullableB-V0F? B-V colour index from Fitzgerald (1970A&A.....4..234F) (4)magphot.color;em.opt.B;em.opt.VfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableB-V0W? B-V colour index from Wegner (1994MNRAS.270..229W) (4)magphot.color;em.opt.B;em.opt.VfloatnullableE(B-V)? Reddening E(B-V) (5)magphot.color.excessfloatnullabler_E(B-V)[1/11]? Reference for E(B-V) (6)meta.ref;pos.frameintnullableNobsa? CRIRES number of observations in central wavelength 1318.1 nmmeta.idintnullableNobsb? CRIRES number of observations in central wavelength 1527.9nmmeta.idintnullableNobsc? CRIRES number of observations in central wavelength 1568.8nmmeta.idintnullableNobsd? CRIRES number of observations in central wavelength 1574.4nmmeta.idintnullableNobse? CRIRES number of observations in central wavelength 1624.2nmmeta.idintnullableJ/A+A/672/A181/tablee1Table of equivalent width measurementsHDHD numbermeta.id;meta.mainintEW-FeI-3859p9? Equivalent width of FeI(3859{AA})0.1nmspect.line.eqWidthfloatnullableEW-DIB-6993p1? Equivalent width of 6993{AA} DIB0.1nmspect.line.eqWidthfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharEW-CNI-3874p6? Equivalent width of CN(3874{AA})0.1nmspect.line.eqWidthfloatnullableEW-CNI-3875p7? Equivalent width of CN(3875{AA})0.1nmspect.line.eqWidthfloatnullableEW-CaII-3933p6? Equivalent width of CaII(3933{AA})0.1nmspect.line.eqWidthfloatnullableEW-KI-4044p1? Equivalent width of KI(40444{AA})0.1nmspect.line.eqWidthfloatnullableEW-C3-4051p6? Equivalent width of C3(4051{AA})0.1nmspect.line.eqWidthfloatnullableEW-CaI-4226p7? Equivalent width of CaI(4226{AA})0.1nmspect.line.eqWidthfloatnullableEW-DIB-4762p6? Equivalent width of 4762{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-4780p0? Equivalent width of 4780{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-4984p8? Equivalent width of 4984{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-4987p4? Equivalent width of 4987{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5074p5? Equivalent width of 5074{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5236p2? Equivalent width of 5236{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5418p9? Equivalent width of 5418{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5450p6? Equivalent width of 5450{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5494p1? Equivalent width of 5494{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6439p5? Equivalent width of 6439{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6445p3? Equivalent width of 6445{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6449p2? Equivalent width of 6449{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6597p4? Equivalent width of 6597{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6614p0? Equivalent width of 6614{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-7224p0? Equivalent width of 7224{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-7562p2? Equivalent width of 7562{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-KI-7698P9? Equivalent width of KI(7698{AA})0.1nmspect.line.eqWidthfloatnullableEW-C2-8757p6? Equivalent width of C2(8757{AA})0.1nmspect.line.eqWidthfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintE(B-V)? Reddening E(B-V)magphot.color.excessfloatnullablelogNH2? log10 of H_2_ column densitylog(cm**-2)phys.columnDensityfloatnullablelogNHI? log10 of HI column densitylog(cm**-2)phys.columnDensityfloatnullablefH2? Fractional H_2_/HI contentphys.mass;arith.ratiofloatnullableEW-1318Equivalent width of 1318nm DIB0.1nmspect.line.eqWidth;em.IR.JfloatEW-1527Equivalent width of 1527nm DIB0.1nmspect.line.eqWidth;em.IR.HfloatEW-1561Equivalent width of 1561nm DIB0.1nmspect.line.eqWidth;em.IR.HfloatEW-1565Equivalent width of 1565nm DIB0.1nmspect.line.eqWidth;em.IR.HfloatEW-1567Equivalent width of 1567nm DIB0.1nmspect.line.eqWidth;em.IR.HfloatEW-NaI-3302p4? Equivalent width of NaI(3302{AA})0.1nmspect.line.eqWidthfloatnullableEW-NaI-3303p0? Equivalent width of NaI(3303{AA})0.1nmspect.line.eqWidthfloatnullableEW-TiII-3383p8? Equivalent width of TiII(3383{AA})0.1nmspect.line.eqWidthfloatnullableEW-FeI-3719p9? Equivalent width of FeI(3719{AA})0.1nmspect.line.eqWidthfloatnullableEW-CNI-3873p9? Equivalent width of CN(3873{AA})0.1nmspect.line.eqWidthfloatnullableEW-CHp-4232p5? Equivalent width of CH+(4232{AA})0.1nmspect.line.eqWidthfloatnullableEW-CH-4300p3? Equivalent width of CH(4300{AA})0.1nmspect.line.eqWidthfloatnullableEW-DIB-4501p8? Equivalent width of 4501{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-4726p8? Equivalent width of 4726{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5705p1? Equivalent width of 5705{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5711p6? Equivalent width of 5711{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-5780? Equivalent width of 5780{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-5797? Equivalent width of 5797{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5766p1? Equivalent width of 5766{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-5849p8? Equivalent width of 5449{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-NaI-5889p9? Equivalent width of NaI(5889{AA})0.1nmspect.line.eqWidthfloatnullableEW-NaI-5895p9? Equivalent width of NaI(5895{AA})0.1nmspect.line.eqWidthfloatnullableEW-DIB-6089p9? Equivalent width of 6089{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6196p0? Equivalent width of 6196{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6203p1? Equivalent width of 6203{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6234p0? Equivalent width of 6234{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6269p9? Equivalent width of 6269{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6283p8? Equivalent width of 6283{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6376p1? Equivalent width of 6376{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6379p3? Equivalent width of 6379{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-DIB-6397p0? Equivalent width of 6397{AA} DIB0.1nmspect.line.eqWidthfloatnullableEW-C2-8761p2? Equivalent width of C2(8761{AA})0.1nmspect.line.eqWidthfloatnullableEW-C2-8763p7? Equivalent width of C2(8753{AA})0.1nmspect.line.eqWidthfloatnullableEW-9632? Equivalent width of 9362{AA} DIB0.1nmspect.line.eqWidthfloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main