J/ApJS/249/16ivo://CDS.VizieR/J/ApJS/249/16doi:10.26093/cds/vizier.22490016CDSMroz P.Udalski A.Szymanski M.K.Soszynski I.Pietrukowicz P.,Kozlowski S.Skowron J.Poleski R.Ulaczyk K.Gromadzki M.Rybicki K.,Iwanek P.Wrona M.2022-11-03T07:31:04Z2020-11-09T08:57:31ZCDS support team

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

cds-question@unistra.frgravitational-lensinggalaxy-planesmilky-way-galaxyphotometryvisible-astronomySearches for gravitational microlensing events are traditionally concentrated on the central regions of the Galactic bulge but many microlensing events are expected to occur in the Galactic plane, far from the Galactic Center. Owing to the difficulty in conducting high-cadence observations of the Galactic plane over its vast area, which are necessary for the detection of microlensing events, their global properties were hitherto unknown. Here, we present results of the first comprehensive search for microlensing events in the Galactic plane. We searched an area of almost 3000 square degrees along the Galactic plane (|b|<7{deg}, 0{deg}<l<50{deg}, 190{deg}<l<360{deg}) observed by the Optical Gravitational Lensing Experiment (OGLE) during 2013-2019 and detected 630 events. We demonstrate that the mean Einstein timescales of Galactic plane microlensing events are on average three times longer than those of Galactic bulge events, with little dependence on the Galactic longitude. We also measure the microlensing optical depth and event rate as a function of Galactic longitude and demonstrate that they exponentially decrease with the angular distance from the Galactic Center (with the characteristic angular scale length of 32{deg}). The average optical depth decreases from 0.5x10^-6^ at l=10{deg} to 1.5x10^-8^ in the Galactic anticenter. We also find that the optical depth in the longitude range 240{deg}<l<330{deg} is asymmetric about the Galactic equator, which we interpret as a signature of the Galactic warp.2020ApJS..249...16Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/249/16CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/278 : Transits observed in OGLE 2001-2003 (Udalski+, 2002-2004)J/AcA/50/1 : OGLE microlensing events in Galactic Bulge (Udalski+, 2000)J/AcA/50/421 : OGLE-II DIA BUL_SC1 field (Wozniak, 2000)J/AcA/51/175 : OGLE-II DIA microlensing events (Wozniak+, 2001)J/A+A/393/887 : SMC Be stars candidates (Mennickent+, 2002)J/A+A/453/635 : Galactic Interstellar Extinction (Marshall+, 2006)J/A+A/500/1027 : EROS CMD towards 4 Galactic spiral arms fields (Rahal+, 2009)J/ApJ/711/L48 : 2008 OGLE Bulge microlensing alerts (Cohen+, 2010)J/ApJ/778/150 : Microlensing events toward the Bulge from MOA-II (Sumi+, 2013)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/ApJS/216/12 : OGLE-III Gal. bulge microlensing events (Wyrzykowski+, 2015)J/MNRAS/458/3012 : OGLE-III Parallax microlensing events (Wyrzykowski+, 2016)J/AcA/68/315 : OGLE Galactic Cepheids (Udalski+, 2018)J/ApJS/244/29 : Microlensing events toward the Galactic bulge (Mroz+, 2019)J/other/Sci/365.478 : Milky Way classical Cepheids sample (Skowron+, 2019)J/A+A/633/A98 : Gaia16aye microlensing event photometry (Wyrzykowski+, 2020)J/A+A/636/A20 : OGLE-III parallax events with Gaia DR2 (Wyrzykowski+, 2020)http://wis-tns.weizmann.ac.il/ : Transient name serverhttp://gsaweb.ast.cam.ac.uk/alerts : Gaia alertshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/249/16https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/249/16http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/249/16https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/249/16https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/249/16http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/249/16GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/249/16/tableb1 (Best-fitting parameters of the analyzed microlensing events in the OGLE GVS fields)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/249/16/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/249/16/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/249/16/tableb1?GETtext/xml+votable180.050000true99.416708313.95513890.005555555555555556Cone search capability for table J/ApJS/249/16/tableb2 (Possible microlensing events)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/249/16/tableb2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/249/16/tableb2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/249/16/tableb2?GETtext/xml+votable180.050000true94.481583320.21886110.005555555555555556Cone search capability for table J/ApJS/249/16/tablea1 (Basic information about analyzed fields)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/249/16/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/249/16/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/249/16/tablea1?GETtext/xml+votable180.050000true279.76667-3.422220.005555555555555556Cone search capability for table J/ApJS/249/16/tablec1 (Surface density of stars in OGLE GVS fields)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/249/16/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/249/16/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/249/16/tablec1?GETtext/xml+votable180.050000true280.23-3.8930.0055555555555555563/338 369 472 583 589 591-592 594 613 615 621 623 651-653 659 662-663 4/1301 1303 1309 1344 1346 1376-1377 1379 1382 1385 1387-1388 1390-1391 1484-1485 1487 1496 1792 1797 1810-1811 1814 1817-1820 1822-1824 1826-1827 1830-1831 1833 1837 1840-1842 1844-1845 1867 1892 1894-1895 1900-1901 1903 1912 1914-1915 2004 2325-2327 2372 2400 2402 2408 2410 2451 2457 2459 2496 2504 2538 2590-2591 2598-2599 2601-2603 2616-2617 2634-2635 2643 2645-2646 2656-2657 2660 2676-2677 2688-2690 2692 2696 2986-2987 2990 5/5200-5201 5203 5209 5245 5247 5333 5382 5388 5390-5391 5432 5434 5512-5513 5515 5520 5522 5537 5556 5558 5893 5895 5945 5947 5952 5954 5960 5962-5963 5992-5994 6033 6036-6037 7172-7173 7184-7185 7187 7197 7199 7202 7208 7210 7225 7228-7229 7231-7232 7234-7235 7237-7239 7248 7250 7262 7265-7267 7284-7286 7302-7303 7314-7315 7317-7319 7329 7341 7344-7346 7372-7374 7388-7389 7391-7393 7465-7467 7482 7574 7588-7589 7591 7608-7609 7626 7654 7674 8001 8004-8005 8022 8025 8028-8029 9299 9413 9415 9421 9423 9445 9447 9453 9455 9492 9496-9498 9520 9604-9606 9612 9636 9638 9797 9799 9924-9925 9927 9933 9935 9957 9992 9994-9995 10024-10026 10112 10114 10120 10122 10144 10146-10147 10346-10347 10350-10351 10358-10359 10381-10383 10387 10389-10391 10401-10403 10472-10474 10480-10481 10526-10527 10530-10531 10533-10535 10570-10571 10588-10590 10632-10634 10636 10644-10645 10688-10689 10692-10693 10712-10714 10716-10717 10719 10764-10766 10772 10792 11937 11939 11943 11954-11955 11958 11964 11966-11967 6/14370 14376 20809 20811 20833 20844-20845 20847 20933 20935 20976-20977 20979 20985 21341 21343 21365 21520 21522-21523 21534 21556 21558 21698 21706 21740 21742 22056-22057 22059 22084 22086-22087 22092 22094-22095 22128 22130 22136 22138-22139 22156-22157 22159 22180-22181 22183 22230 22236-22238 22442 23568-23569 23571 23577 23605-23607 23612-23613 23615 23701 23709 23777 23779 23785 23822 23844 23846-23847 23952 23954 23960 23962 23980 23984 24129 24141 24320 28696-28697 28699-28701 28704 28744-28745 28747 28773 28784-28785 28787 28793 28800 28803 28806-28807 28812-28813 28815 28824 28826 28846-28847 28858 28879 28885 28890-28891 28895 28897 28899 28932 28934 28998 29004 29006-29007 29040 29042-29043 29052 29054-29057 29059 29148 29150-29151 29200 29202-29203 29206-29207 29267 29312-29313 29325 29361 29388-29389 29408 29410 29425 29500-29501 29540-29541 29543 29560-29561 29563 29576-29578 29580-29581 29584-29585 29652-29653 29854-29856 29858-29859 29920 29922-29923 29932 29934 30290 30302 30341 30361 30389 30441 30444-30445 30447 30498 30510 30610 30622 30690 30702 31824-31825 31828-31829 32000-32001 32003 32012-32013 32024-32025 32027-32029 32031 32082 32094 32096-32097 32125 37187 37189-37191 37193 37195 37279 37301 37303 37309-37311 37659 37691 37785 37787 37811 37817 37972-37973 37976 37978 37996-37998 38084 38088-38090 38112 38114 38428-38430 38452 38456 38458-38459 38576 38578 38584 38586 39185 39187 39193 39195 39335 39704-39705 39707 39729 39731 39737 39836-39837 39839 39861 39863 39869 39871 39954 39972 39974-39975 40088 40108 40112 40114 40460 40484 40486 40492 40494-40495 40580 40582-40583 40624 40632 40634 41214-41215 41394-41395 41397-41399 41419 41422-41423 41503 41519 41523 41542-41543 41545-41547 41553-41555 41603 41900 41904-41905 41928-41929 41936-41937 41940-41941 42090-42091 42094-42095 42103 42115 42118-42119 42129-42131 42274-42276 42278-42279 42311 42317 42319 42364 42366 42540-42541 42548-42550 42584-42586 42588-42590 42592-42593 42596 42760 42764-42765 42776-42777 42780-42781 42807 42813-42815 42860-42862 42872-42873 42875 42901 42944-42945 42964-42965 43068-43070 43092-43094 43104-43105 43108 43152 43154 43176 47747 47753 47755 47767 47810-47811 47838 47860 47862-47863 48043https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/249/16?format=asciiOpticaldefaultJ/ApJS/249/16/tableb1Best-fitting parameters of the analyzed microlensing events in the OGLE GVS fieldsweight[7.7/280.2] Inverse of the detection efficiencystat.weightdoubleOIDOther identifiermeta.idcharLCInteractive LC plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOGLEStar name (<OGLE GDFFFF.FF.FFFFF>, <OGLE DGFFFF.FF.NNNNN> or <OGLE BLGFFFF.FF FFFFF> in Simbad)meta.id;meta.maincharSimbadNameSimbad column added by the CDSmeta.idcharnullablesFieldOGLE-IV subfield nameobs.fieldcharStar[51/115188] Star ID in the OGLE-IV databasemeta.idintRAJ2000Hour of Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainGLONGalactic longitudedegpos.galactic.lonGLAT[-11.51/14.91] Galactic latitudedegpos.galactic.latdoublet0Best-fit HJD time of closest approachdtime.epoch;meta.modelleddoubletE[3.29/457.6] Best-fit Einstein radius crossing timescaledtime.scalefloatu0[0/0.98] Best-fit separation at closest approachsrc.impactParamfloatIs[14.1/21] Best-fit source brightnessmagphot.mag;meta.modelledfloatfs[0.014/2.1] Best-fit blending parameterphys.luminosity;arith.ratiofloatt0MedMedian HJD time of closest approachdtime.epoch;stat.mediandoublee_t0[0.005/23.3] Lower 1{sigma} uncertainty in t0dstat.errorfloatE_t0[0.005/29.7] Upper 1{sigma} uncertainty in t0dstat.error;stat.maxfloattEMed[3.38/409.5] Median Einstein radius crossing timescaledtime.scalefloate_tE[0.06/121.1] Lower 1{sigma} uncertainty in tEdstat.errordoubleE_tE[0.1/272.5] Upper 1{sigma} uncertainty in tEdstat.error;stat.maxfloatu0Med[0.002/0.9] Median separation at closest approachsrc.impactParamfloate_u0[0.001/0.3] Lower 1{sigma} uncertainty in u0stat.errorfloatE_u0[0.001/0.41] Upper 1{sigma} uncertainty in u0stat.error;stat.maxfloatIsMed[14.4/21.1] Median source brightnessmagphot.mag;meta.modelledfloate_Is[0.008/1.2] Lower 1{sigma} uncertainty in Ismagstat.errorfloatE_Is[0.015/2.8] Upper 1{sigma} uncertainty in Ismagstat.error;stat.maxfloatfsMed[0.017/1.9] Median blending parameterphys.luminosity;arith.ratiofloate_fs[0.009/0.7] Lower 1{sigma} uncertainty in fsstat.errorfloatE_fs[0.007/0.6] Upper 1{sigma} uncertainty in fsstat.error;stat.maxfloatJ/ApJS/249/16/tableb2Possible microlensing eventsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOGLEStar namemeta.id;meta.maincharRAJ2000Hour of Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainGLON[2.29/359.4] Galactic longitudedegpos.galactic.lonGLAT[-10.05/10.15] Galactic latitudedegpos.galactic.latdoubleRemarksRemarksmeta.notecharLCInteractive LC plotmeta.ref.urlcharJ/ApJS/249/16/tablea1Basic information about analyzed fieldsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFieldField nameobs.fieldcharRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainNep[34/1214] Number of epochsmeta.numberintdeltaT[127/3122] Duration of monitoringdtime.durationintEff20Interactive plotmeta.ref.urlcharEff21Interactive plotmeta.ref.urlcharGLONGalactic longitudedegpos.galactic.lonGLAT[-15.28/15.74] Galactic latitudedegpos.galactic.latdoubleNs[0.07/4.61] Number of stars in the databasemeta.numberfloatJ/ApJS/249/16/tablec1Surface density of stars in OGLE GVS fieldsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintsFieldSubfield nameobs.fieldcharRAJ2000[85/289.2] Right ascension (J2000)degpos.eq.ra;meta.mainindexedDEJ2000[-70.1/23.6] Declination (J2000)degpos.eq.dec;meta.mainindexedGLON[-171.5/56.6] Galactic longitudedegpos.galactic.lonGLAT[-15.91/16.4] Galactic latitudedegpos.galactic.latfloatsigma20[2.7/798.6] Surface density of sources brighter than I=20arcmin**-2src.densityfloatsigma21[7.8/1549] Surface density of sources brighter than I=21arcmin**-2src.densityfloatN20[426/133348] Number of sources brighter than I=20meta.numberintN21[1245/258646] Number of sources brighter than I=21meta.numberint