J/ApJ/733/91ivo://CDS.VizieR/J/ApJ/733/91doi:10.26093/cds/vizier.17330091CDSXiang F.Y.Li A.Zhong J.X.2017-12-05T05:10:32Z2012-12-10T08:47:04ZCDS support team

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

cds-question@unistra.frinterstellar-mediumline-intensitiesThe diffuse interstellar bands (DIBs) are ubiquitous absorption spectral features arising from the tenuous material in the space between stars -the interstellar medium (ISM). Since their first detection nearly nine decades ago, over 400 DIBs have been observed in the visible and near-infrared wavelength range in both the Milky Way and external galaxies, both nearby and distant. However, the identity of the species responsible for these bands remains as one of the most enigmatic mysteries in astrophysics. An equally mysterious interstellar spectral signature is the 2175{AA} extinction bump, the strongest absorption feature observed in the ISM. Its carrier also remains unclear since its first detection 46 years ago. Polycyclic aromatic hydrocarbon (PAH) molecules have long been proposed as a candidate for DIBs as their electronic transitions occur in the wavelength range where DIBs are often found. In recent years, the 2175{AA} extinction bump is also often attributed to the {pi}-{pi}* transition in PAHs. If PAHs are indeed responsible for both the 2175{AA} extinction feature and DIBs, their strengths may correlate. We perform an extensive literature search for lines of sight for which both the 2175{AA} extinction feature and DIBs have been measured. Unfortunately, we found no correlation between the strength of the 2175{AA} feature and the equivalent widths of the strongest DIBs. A possible explanation might be that DIBs are produced by small free gas-phase PAH molecules and ions, while the 2175{AA} bump is mainly from large PAHs or PAH clusters in condensed phase so that there is no tight correlation between DIBs and the 2175{AA} bump.2011ApJ...733...91Xhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/733/91CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/148 : Interstellar lines catalogue (Garcia 1991)II/135 : Suppl. to Diffuse Interstellar Band Measurements (Guarinos 1988)II/149 : Diffuse Interstellar Band Measurements (Snow+ 1977)J/ApJ/708/1628 : Diffuse interstellar bands. IV. (McCall+, 2010)J/ApJ/705/32 : Diffuse interstellar bands from HD 183143 (Hobbs+, 2009)J/MNRAS/358/563 : Diffuse Interstellar Bands in 49 stars (Megier+, 2005)J/A+A/429/559 : Diffuse Interstellar Bands in NGC 1448 (Sollerman+, 2005)J/A+A/414/949 : Interstellar bands and H2, CH, CO column densities (Weselak+J/AN/324/219 : Extinction of OB stars (Wegner, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/733/91https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/733/91http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/733/91https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/733/91https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/733/91http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/733/91GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/733/91/table1 (The 2175{AA} extinction bump strengths (W_2175_) and DIB equivalent widths (WDIB) for 84 interstellar sightlines)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/733/91/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/733/91/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/733/91/table1?GETtext/xml+votable180.050000true8.24996362.9317820.0055555555555555566/859 1055 1060 1287 1293 1539 1550 3060 3231 3284 3307 3312 3430 14015 14431 14644 14653 14654 14690 15369 15392 15396 15399 15478 15486 15519 15663 15682 15683 15687 15745 15747 19009 21439 22223 22249 22253 22258 22854 22855 23979 24179 24338 24463 24513 24552 28890 28891 28900 28913 29089 29463 29513 30709 30718 30818 31121 38016 41592 41692 42394 42977 42981 42994 44305 44360 44366 44378 44386 44389https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/733/91?format=asciiOpticaldefaultJ/ApJ/733/91/table1The 2175{AA} extinction bump strengths (W_2175_) and DIB equivalent widths (WDIB) for 84 interstellar sightlinesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarHD or BD namemeta.idcharprimaryE(B-V)Interstellar reddening E(B-V) (1)magphot.color.excessfloatRv? Total-to-selective extinction ratio (R_V_=A_V_/E(B-V); A_V_= V-band extinction)phys.absorption.gal;arith.ratiofloatnullablee_Rv? Rv uncertaintystat.errorfloatnullabler_Rv? Rv reference (2)meta.ref;pos.frameintnullablec3Parameter c_3_ that relates to the strength of the bumpum**-2stat.param;phys.atmol.collStrengthfloatr_c3c3 reference (2)meta.ref;pos.frameintgammaBand width {gamma} (extinction parameter)um**-1stat.fit.paramfloatr_gammaGamma reference (2)meta.ref;pos.frameintW2175W_2175_/E(B-V) (3)um**-1phys.absorptionfloatW5707? 5707 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW57805780 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatW5797? 5797 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW6195? 6195/6196 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW6203? 6203 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW6269? 6269/6270 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW6284? 6284 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW6376? 6376/6379 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableW6614? 6614 equivalent width in milli{AA} (1)0.1pmspect.line.eqWidthfloatnullableSimbadSimbad column added by the CDSmeta.refchar_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/ApJ/733/91/table3Sources for the equivalent widths of the 5707, 5780, 5797, 6203, 6284, and 6614 DIBsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDIB[5707/6614] DIB wavelength identification; in Angstroms0.1nmem.wlintStar[2905/+631964] Stellar HD or BD IDmeta.idcharE(B-V)[0.05/1.28] E(B-V)magphot.color.excessfloatW2175The 2175 equivalent width divided by E(B-V)um**-1phys.absorptionfloatW? Equivalent width of DIB (in milli{AA})0.1pmspect.line.eqWidthfloatnullablee_W? Uncertainty in W (in milli{AA})0.1pmstat.error;pos.cartesian.zfloatnullableq_W[AX] Adopt/Reject code (G1)meta.code.qual;pos.cartesian.zcharAutAuthor's name for Refmeta.bib.authorcharRefBibcode of source referencemeta.bib.bibcodecharWado[5/1888]? Adopted equivalent width of DIB (in milli-Angstroms)0.1pmspect.line.eqWidthfloatnullableJ/ApJ/733/91/table4Sources for the equivalent widths of the 6195/6996, 6269/6270, and 6376/6379 DIBsAutAuthor's name for Refmeta.bib.authorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDIB1DIBs pair wavelength identification; in {AA}0.1nmem.wlintDIB2DIBs pair wavelength identification; in {AA}0.1nmem.wlintStar[2905/+631964] Stellar HD or BD IDmeta.idcharE(B-V)[0.05/1.28] E(B-V)magphot.color.excessfloatW2175The 2175 equivalent width divided by E(B-V)um**-1phys.absorptionfloatl_W1Limit flag on W1meta.code.errorcharW1? Equivalent width of 1st DIB in pair (in m{AA})0.1pmspect.line.eqWidthfloatnullablee_W1? Uncertainty in W1 (in milli{AA})0.1pmstat.errorfloatnullableq_W1[AX] Adopt/Reject code for 1st DIB in pair (G1)meta.code.qualcharW2? Equivalent width of 2nd DIB in pair (in m{AA})0.1pmspect.line.eqWidthfloatnullablee_W2? Uncertainty in W2 (in milli{AA})0.1pmstat.errorfloatnullableq_W2[AX] Adopt/Reject code for 2nd DIB in pair (G1)meta.code.qualcharRefBibcode of source referencemeta.bib.bibcodecharWado[2.5/246.9]? Adopted DIB equivalent widths (in milli-Angstroms)0.1pmspect.line.eqWidthfloatnullable