J/ApJ/935/175ivo://CDS.VizieR/J/ApJ/935/175doi:10.26093/cds/vizier.19350175CDSDeng D.Sun Y.Wang T.Wang Y.Jiang B.2024-11-06T20:26:46Z2024-06-27T07:46:51ZCDS support team

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

cds-question@unistra.frob-starsinfrared-photometryvisible-astronomyThe infrared (IR) excess from OB stars is commonly considered to be a contribution from ionized stellar wind or circumstellar dust. With the newly published Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST)-OB catalog and Galactic O-Star Spectroscopic Survey data, this work steps further on understanding the IR excess of OB stars. Based on a forward-modeling approach comparing the spectral slope of observational spectral energy distributions and photospheric models, 1147 stars are found to have IR excess out of 7818 stars with good-quality photometric data. After removing the objects in the sightline of dark clouds, 532(~7%) B-type stars and 118(~23%) O-type stars are identified to be true OB stars with circumstellar IR excess emission. The ionized stellar wind model and the circumstellar dust model are adopted to explain the IR excess, and Bayes factors are computed to quantitatively compare the two. It is shown that the IR excess can be accounted for by the stellar wind for about 65% cases, of which 33% by free-free emission and 32% by synchrotron radiation. Other 30% sources could have and 4% should have a dust component or other mechanisms to explain the sharp increase in flux at {lambda}>10{mu}m. The parameters of the dust model indicate a large-scale circumstellar halo structure, which implies the origin of the dust from the birthplace of the OB stars. A statistical study suggests that the proportion with IR excess in OB stars increases with the stellar effective temperature and luminosity, and that there is no systematic change in the mechanism for IR emission with stellar parameters.2022ApJ...935..175Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/935/175CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/297 : AKARI/IRC mid-IR all-sky Survey (ISAS/JAXA, 2010)I/337 : Gaia DR1 (Gaia Collaboration, 2016)I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)VI/39 : Model Atmospheres (Kurucz, 1979)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VII/244 : Atlas and Catalog of Dark Clouds (Dobashi+, 2005)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)VIII/106 : Herschel/PACS Point Source Catalogs (Herschel team, 2017)J/ApJ/663/320 : IR-through-UV extinction curve (Fitzpatrick+, 2007)J/A+A/481/345 : SED evolution massive young stellar objects (Molinari+, 2008)J/PASJ/63/S1 : Atlas & catalog of dark clouds based on 2MASS (Dobashi+, 2011)J/ApJS/224/4 : GOSSS III. 142 additional Otype systems (Maiz Apellaniz+, 2016)J/A+A/620/A32 : IRS spectra of 22 O7-B5 I-V stars (Siebenmorgen+, 2018)J/ApJ/852/78 : JHKs, WISE and Spitzer data of Galactic Cepheids (Wang+, 2018)J/ApJS/241/32 : OB stars from the LAMOST DR5 spectra (Liu+, 2019)J/ApJS/257/54 : Early-type star param. from LAMOST LRS & MRS (Guo+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/935/175https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/935/175http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/935/175https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/935/175https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/935/175http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/935/175GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/935/175/table2 (The parameters of the stars with IR excess from LAMOST)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/935/175/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/935/175/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/935/175/table2?GETtext/xml+votable180.050000true72.610340.94710.0055555555555555565/324 333 480 792 814-815 900 5940 6/478 1220 1227 1283 1285 1287 1293 1300 1302 1304-1305 1308 1310-1311 1316 1329-1330 1339 1341 1343 1353-1355 1359-1360 1363 1368 1370 1377 1380 1385 1411 1415 1417 1422-1423 1427 1430 1433 1435-1437 1455 1458-1459 1461-1462 1466 1471 1474 1481 1507 1519 1555 1578 1652-1653 1655 1661-1662 1722 1729 1735 1744 1753 1756 1758 1763 1765 1771 1773 1775 1778 1790 1795 1801 1804 1806 1808 1817-1819 1834 1928 1930-1934 1938-1939 1942 1945 1952-1954 1956 1962 1966-1967 1974 1989 2722 2834 2873 2908 2910 2937 2940-2941 2943 2967 2975 2989 2996 2998-2999 3002 3015-3016 3018 3022 3024 3026 3032 3040 3042-3043 3045 3048-3050 3055 3087 3093-3094 3096 3101 3122 3125 3134 3138 3145-3146 3150 3156 3162 3173-3176 3181-3182 3219 3222 3231 3239 3246-3247 3250 3252 3254-3255 3268-3270 3274 3328 3330-3331 3337 3340 3347 3361 3497 3588-3589 3591 3599 3604 3620 3728 6446 9074 9785 12983 13035 13289 13292-13293 13295 13304 13447 13979 14148 14154 14171 14178 14180 14187 14196-14198 14200 14217 14219 14237-14239 14241 14243 14247 14253 14255 14259-14262 14264-14266 14278 14280 14283 14286 14291 14295 14297 14299-14301 14304-14305 14307 14309 14389 14401 14405 14410 14414 14419 14428-14429 14435 14440 14453 14594 14612 14615 14657-14658 14771 14773 14781 14787 14792 14795-14797 14806 14818 14920 14956 15474 15623 15632 15640 15875 19741 21457 21495 21502 21733 21744 21946 22055-22056 22058 22076 22107 22115 22120 22124 22126 22128 22136 22140 22165 22167 22171 22173-22174 22196-22197 22199 22201 22208-22209 22212-22213 22220 22223 22226 22230 22234 22237 22242 22247-22248 22253 22257 22260 22263 22404 22411 22433 22436 22439 22885 23394 23593 23619-23621 23633 23640 23672 23674-23675 23678 23709 23720 23729 23732 23736 23756 23759 23766-23767 23773 23780 23788 23801-23802 23870 23931 23938 23949 23975 23986 23993 23995 24010 24087 24116 24145 24147 24157 24182 24188 24326-24327 24333 24337-24338 24340 24342 24344 24348 24353 24357 24360 24370-24371 24375-24376 24380 24382 24384 24393 24452 24466 24468 24470-24471 24478 24486 24491 24493 24495 24500 24503 24507 24512 24516 24526 24533 24540 24545 24549-24551 24561 30303 30390 30470 31816 31876 32034https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/935/175?format=asciiOpticalInfrareddefaultJ/ApJ/935/175/table2The parameters of the stars with IR excess from LAMOSTrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[0/360] Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-7/66] Declination (J2000)degpos.eq.dec;meta.mainTeff[10149/57691] Effective temperatureKphys.temperature.effectiveintlogg[3.51/6.15] Surface gravity, loglog(cm.s**-2)phys.gravityfloatE(B-V)[-0.15/2.61] Color excess of (B-V) (1)magphot.color.excessfloatLumLuminositysolLumphys.luminositychare_LumUncertainty on LuminositysolLumstat.errorcharRadStellar RadiussolRadphys.size.radiuschare_RadUncertainty on Stellar RadiussolRadstat.errorcharBestBest model (2)stat.paramcharBF? Bayes Factor (3)stat.fit.paramcharalpha[-10.0/2.0]? Spectral index from the best stellar wind modelspect.indexfloatnullableb_alpha[-10.0/1.9]? Lower limit of the 68% confidential interval of alphatime.interval;stat.minfloatnullableB_alpha[-7.8/2.0]? Upper limit of the 68% confidential interval of alphatime.interval;stat.maxfloatnullabletau? Optical depth at 550nm from the best DUSTY modelphys.absorption.opticalDepthcharb_tau? Lower limit of the 68% confidential interval of tautime.interval;stat.mincharB_tau? Upper limit of the 68% confidential interval of tautime.interval;stat.maxcharTdinner[300/1400]? Dust inner temperature from the best DUSTY modelKphys.temperatureintnullableb_Tdinner[300/1350]? Lower limit of the 68% confidential interval of TdinnerKtime.interval;stat.minintnullableB_Tdinner[350/1400]? Upper limit of the 68% confidential interval of TdinnerKtime.interval;stat.maxintnullableJ/ApJ/935/175/table3The parameters of the stars with IR excess from GOSSSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharTeff[10000/50000] Effective temperatureKphys.temperature.effectiveintlogg[3.5/5.0] Surface gravity, loglog(cm.s**-2)phys.gravityfloatE(B-V)[0.31/1.45] Color excess of (B-V) (1)magphot.color.excessfloatalpha[-10.0/2.0]? Spectral index from the best stellar wind modelspect.indexfloatnullableb_alpha[-10.0/1.9]? Lower limit of the 68% confidential interval of alphatime.interval;stat.minfloatnullableB_alpha[-7.5/2.0]? Upper limit of the 68% confidential interval of alphatime.interval;stat.maxfloatnullabletau? Optical depth at 550nm from the best DUSTY modelphys.absorption.opticalDepthcharb_tau? Lower limit of the 68% confidential interval of tautime.interval;stat.mincharB_tau? Upper limit of the 68% confidential interval of tautime.interval;stat.maxcharTdinner[300/1400]? Dust inner temperature from the best DUSTY modelKphys.temperatureintnullableb_Tdinner[300/1200]? Lower limit of the 68% confidential interval of TdinnerKtime.interval;stat.minintnullableB_Tdinner[350/1400]? Upper limit of the 68% confidential interval of TdinnerKtime.interval;stat.maxintnullableLumLuminositysolLumphys.luminositychare_LumUncertainty on LuminositysolLumstat.errorcharRadStellar RadiussolRadphys.size.radiuschare_RadUncertainty on Stellar RadiussolRadstat.errorcharBestBest model (2)stat.paramcharBF? Bayes Factor (3)stat.fit.paramchar