J/ApJ/850/194ivo://CDS.VizieR/J/ApJ/850/194doi:10.26093/cds/vizier.18500194CDSFan H.Welty D.E.York D.G.Sonnentrucker P.Dahlstrom J.A.Baskes N.,Friedman S.D.Hobbs L.M.Jiang Z.Rachford B.Snow T.P.Sherman R.,Zhao G.2018-09-10T08:21:05Z2018-08-20T09:57:14ZCDS support team

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

cds-question@unistra.frb-starsstellar-spectral-typesline-intensitiesinterstellar-mediumvisible-astronomyspectroscopyWe study the behavior of eight diffuse interstellar bands (DIBs) in different interstellar environments, as characterized by the fraction of hydrogen in molecular form (f_H2_), with comparisons to the corresponding behavior of various known atomic and molecular species. The equivalent widths of the five "normal" DIBs ({lambda}{lambda}5780.5, 5797.1, 6196.0, 6283.8, and 6613.6), normalized to E_B-V_, show a "lambda-shaped" behavior: they increase at low f_H2_, peak at f_H2_~0.3, and then decrease. The similarly normalized column densities of Ca, Ca+, Ti+, and CH+ also decline for f_H2_>0.3. In contrast, the normalized column densities of Na, K, CH, CN, and CO increase monotonically with fH2, and the trends exhibited by the three C_2_ DIBs ({lambda}{lambda}4726.8, 4963.9, and 4984.8) lie between those two general behaviors. These trends with f_H2_ are accompanied by cosmic scatter, the dispersion at any given f_H2_ being significantly larger than the individual errors of measurement. The lambda-shaped trends suggest the balance between creation and destruction of the DIB carriers differs dramatically between diffuse atomic and diffuse molecular clouds; additional processes aside from ionization and shielding are needed to explain those observed trends. Except for several special cases, the highest W{lambda}(5780)/W{lambda}(5797) ratios, characterizing the so-called "sigma-zeta effect," occur only at f_H2_<0.2. We propose a sequence of DIBs based on trends in their pair-wise strength ratios with increasing f_H2_. In order of increasing environmental density, we find the {lambda}6283.8 and {lambda}5780.5 DIBs, the {lambda}6196.0 DIB, the {lambda}6613.6 DIB, the {lambda}5797.1 DIB, and the C_2_ DIBs.2017ApJ...850..194Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/850/194CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/147/61 : Interstellar Ca I absorption (Welty+, 2003)J/A+A/414/949 : H2, CH, CO column densities (Weselak+ 2004)J/MNRAS/358/563 : Diffuse Interstellar Bands in 49 stars (Megier+, 2005)J/ApJ/705/32 : Diffuse interstellar bands from HD 183143 (Hobbs+, 2009)J/ApJ/700/1299 : Gas-phase element depletions in the ISM (Jenkins, 2009)J/ApJ/711/1236 : Equivalent width of H_2_ from FUSE (Jensen+, 2010)J/ApJ/708/1628 : Diffuse interstellar bands. IV. (McCall+, 2010)J/MNRAS/404/1321 : TiII in Milky way and Magellanic clouds (Welty+, 2010)J/ApJ/733/91 : Diffuse interstellar band equivalent widths (Xiang+, 2011)J/A+A/544/A136 : Diffuse Interstellar Bands in 150 stars (Raimond+, 2012)J/MNRAS/423/725 : Survey of diffuse interstellar bands (Bondar, 2012)J/A+A/555/A25 : Equivalent widths of DIBs (Puspitarini+, 2013)J/ApJ/774/72 : Measurements of 19 DIBs (Kos+, 2013)J/ApJS/225/19 : DIBs measurements from SDSS-III APOGEE (Elyajouri+, 2016)J/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/ApJ/850/194https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/850/194http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/850/194https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/850/194https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/850/194http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/850/194GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/850/194/table1 (Spectral types and values of E(B-V), N(H), N(H2), f_H2_, and EWs of the eight diffuse interstellar bands (DIBs) for 186 O and B stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/850/194/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/850/194/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/850/194/table1?GETtext/xml+votable180.050000true3.308923615.18353860.0055555555555555566/418 859 1055 1060 1196 1198 1293 1332 1539 1550 1558 2409 2884 3058 3060 3251 3256 3283 3307 3312 3430 3600 3637 5506 11875 13255 13331 13557 13729 13953 14015 14167 14197 14220 14240 14305 14431 14643 14644 14691 14692 14734 14777 14805 15369 15392 15406 15478 15479 15486 15553 15577 15624 15631 15652 15656 15662 15672 15687 15745 15747 16131 18439 18928 19009 19336 19676 20107 20613 20759 20847 20915 21401 21432 21438 21439 21456 21479 21635 21646 21647 21879 21893 21943 22033 22123 22240 22249 22253 22258 22503 22579 22772 22805 22854 22855 22859 22862 22884 22893 23298 23637 23714 23717 23979 23995 23998 24338 24340 24370 24463 24504 24513 25988 27498 28890 28900 29089 29116 29138 29162 29463 29513 29522 29537 29600 29876 30718 30722 30818 36958 39281 39334 39853 39907 39916 41129 41510 41663 42080 42383 42394 42408 42417 42456 42470 42924 42948 42959 42977 42980 42981 42994 43024 43062 44305 44312 44360 44366 44378 44389https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/850/194?format=asciiOpticaldefaultJ/ApJ/850/194/table1Spectral types and values of E(B-V), N(H), N(H2), f_H2_, and EWs of the eight diffuse interstellar bands (DIBs) for 186 O and B starsSimbadNameSimbad column added by the CDSmeta.idcharl_N(H)Limit flag on N(H)meta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharSpTMK spectral typesrc.spTypecharE(B-V)[0/3.4] Reddening, E(B-V)magphot.color.excessfloate_E(B-V)[0.01/0.1]? Uncertainty in E(B-V)magstat.errorfloatnullableN(H)[19.4/22]? Log Column density, Hlog(cm**-2)phys.densityfloatnullablee_N(H)[0.04/0.3]? Uncertainty in N(H)log(cm**-2)stat.errorfloatnullablef_N(H)Flag on N(H) (1)meta.codecharl_N(H2)Limit flag on N(H2)meta.code.errorcharN(H2)[14.5/21.5]? Log Column density, H2log(cm**-2)phys.columnDensityfloatnullablee_N(H2)[0.01/0.4]? Uncertainty in N(H2)log(cm**-2)stat.errorfloatnullablef_N(H2)Flag on N(H2) (1)meta.codecharl_fH2Limit flag on fH2meta.code.errorcharfH2? Fraction of hydrogen in molecular formphys.abund.X;arith.ratiodoublenullablee_fH2[0/0.3]? Uncertainty in fH2stat.errorfloatnullablel_W(4727)Limit flag on W(4727)meta.code.errorcharW(4727)[4.7/343]? Equivalent width, 4727{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(4727)[0.5/15.2]? Uncertainty in W(4727)0.0001nmstat.errorfloatnullablef_W(4727)Flag on W(4727) (1)meta.codecharl_W(4963)Limit flag on W(4963)meta.code.errorcharW(4963)[0.6/68.5]? Equivalent width, 4963{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(4963)[0.1/2.6]? Uncertainty in W(4963)0.0001nmstat.errorfloatnullablef_W(4963)Flag on W(4963) (1)meta.codecharl_W(4984)Limit flag on W(4984)meta.code.errorcharW(4984)[0.4/32.7]? Equivalent width, 4984{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(4984)[0.1/2.1]? Uncertainty in W(4984)0.0001nmstat.errorfloatnullablel_W(5780)Limit flag on W(5780)meta.code.errorcharW(5780)[4/891.2]? Equivalent width, 5780{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(5780)[0.8/11.2]? Uncertainty in W(5780)0.0001nmstat.errorfloatnullablef_W(5780)Flag on W(5780) (1)meta.codecharl_W(5797)Limit flag on W(5797)meta.code.errorcharW(5797)[2/356]? Equivalent width, 5797{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(5797)[0.1/4.3]? Uncertainty in W(5797)0.0001nmstat.errorfloatnullablef_W(5797)Flag on W(5797)(1)meta.codecharl_W(6196)Limit flag on W(6196)meta.code.errorcharW(6196)[0.5/106.4]? Equivalent width, 6196{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(6196)[0.1/2]? Uncertainty in W(6196)0.0001nmstat.errorfloatnullablel_W(6284)Limit flag on W(6284)meta.code.errorcharW(6284)[7/2287]? Equivalent width, 6284{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(6284)[0.9/30.7]? Uncertainty in W(6284)0.0001nmstat.errorfloatnullablef_W(6284)Flag on W(6284) (1)meta.codecharl_W(6613)Limit flag on W(6613)meta.code.errorcharW(6613)[0.9/427.4]? Equivalent width, 6613{AA} (2)0.0001nmspect.line.eqWidthfloatnullablee_W(6613)[0.2/3.7]? Uncertainty in W(6613)0.0001nmstat.errorfloatnullablef_W(6613)Flag on W(6613) (1)meta.codechar_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