J/MNRAS/448/2210ivo://CDS.VizieR/J/MNRAS/448/2210doi:10.26093/cds/vizier.74482210CDSEvans P.A.Osborne J.P.Kennea J.A.Smith M.Palmer D.M.Gehrels N.,Gelbord J.M.Homeier A.Voge M.Strotjohann N.L.Cowen D.F.Boser S.,Kowalski M.Stasik A.2024-08-14T20:20:08Z2015-12-18T12:28:54ZCDS support team

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

cds-question@unistra.frBetween 2011 March and 2014 August Swift responded to 20 triggers from the IceCube neutrino observatory, observing the IceCube 50 percent confidence error circle in X-rays, typically within 5h of the trigger. No confirmed counterpart has been detected. We describe the Swift follow-up strategy and data analysis and present the results of the campaign. We discuss the challenges of distinguishing the X-ray counterpart to a neutrino trigger from serendipitous uncatalogued X-ray sources in the error circle, and consider the implications of our results for future strategies for multimessenger astronomy, with particular reference to the follow-up of gravitational wave triggers from the advanced-era detectors.2015MNRAS.448.2210Ehttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/448/2210CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/448/2210https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/448/2210http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/448/2210https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/448/2210https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/448/2210http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/448/2210GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/448/2210/table2 (Sources detected in the XRT follow-up of the IceCube triggers)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/448/2210/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/448/2210/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/448/2210/table2?GETtext/xml+votable180.050000true52.7712513.9333330.0055555555555555566/297 4708 5416 5418-5419 11471 14773 14775 14816 15621 18327 18370 19230-19231 20062 23165 23253 23255 26108 27293 27336 27338 27631 27642 27930 27952 30330 30416 31779 31785https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/448/2210?format=asciiGamma-rayX-raydefaultJ/MNRAS/448/2210/table1Details of the 20 IceCube triggers followed up by Swift as of 2014 September 03recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTriggerIceCube Trigger numberobs.fieldinteRadError radius (50% confidence)degstat.errorfloatObsTrigger datestime.epochnullableDelayTime between the possible neutrino event detected by IceCube and the start of the first observation with the Swift-XRThtime.start;obsfloatTypeTiling type (Manual or Automatic)meta.code;obscharJ/MNRAS/448/2210/table2Sources detected in the XRT follow-up of the IceCube triggersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTriggerIceCube trigger field numberobs.fieldintSourceSource number, within the trigger fieldmeta.idintn_Source[j] Note for no XRT spectral fit available (1)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.maine_PosPosition error radius, 90% confidencearcsecstat.errorfloatn_Pos[*i] Note on position (1)meta.notecharFlag[GPR] Flag (2)meta.code.errorcharExpTimeExposure timekstime.duration;obs.exposurefloatCountNumber of counts found in the region used to detect the sourcectphot.count;em.X-rayintCountExpNumber expected from the backgroundctmeta.id;meta.mainfloatFluxObserved (i.e. absorbed) flux. For objects with more than one light-curve bin, peak observed flux, in 0.3-10keV band1e-16W.m**-2phot.flux;em.X-raydoubleE_FluxError on Flux (upper value)1e-16W.m**-2stat.error;stat.maxfloate_FluxError on Flux (lower value)1e-16W.m**-2stat.error;phot.fluxfloatn_Flux[k] Note for no XRT light curve was available (1)meta.notecharFluxM? For objects with more than one light-curve bin, mean observed flux1e-16W.m**-2phot.flux;em.X-rayfloatnullablee_FluxM? rms uncertainty on FluxM1e-16W.m**-2stat.errorfloatnullableFluxUL? Upper limit for 0.3-10keV band flux, from the RASS unless otherwise indicated (3)phot.flux;em.X-rayfloatnullablen_FluxUL[l] Note for a very hard source (1)meta.notecharNserenNumber of sources at least as bright as this one, expected in the XRT field of view (see Section 4.2 for details)meta.numberfloatPconst? Probability that the source is constant, from a chi^2^ test, only available if the light curve contained at least two binsstat.fit.goodnessdoublenullableCat?[Y] Whether a catalogued source was found which matched this object; details are given in Table 4.meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/448/2210/table3Details of the X-ray sources with spectral_NHiLimit flag on NHimeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTriggerIceCube trigger field numberobs.fieldintSourceSource number, within the trigger fieldmeta.idintNHGGalactic absorption value, taken from Willingale et al. (2013MNRAS.431..394W)1e+20cm**-2phys.absorption.galfloatNHiIntrinsic absorption, fitted to the spectrum1e+20cm**-2phys.absorptionfloatE_NHi? Error on NHi (upper value)1e+20cm**-2stat.error;stat.maxintnullablee_NHi? Error on NHi (lower value)1e+20cm**-2stat.errorfloatnullablel_IndexLimit flag in Indexmeta.code;spect.indexcharIndex? Photon indexspect.indexfloatnullableE_Index? Error on Index (upper value)stat.error;stat.maxfloatnullablee_Index? Error on Index (lower value)stat.error;spect.indexfloatnullablen_Index[e] e: Photon index was unconstrainedmeta.notecharECFConversion from XRT measured count rate to 0.3-10keV observed flux1e-14W.m**-2phot.count;em.X-rayfloatPSPCConversion from XRT measured count rate to that expected in the ROSAT PSPCphot.count;em.X-rayfloatJ/MNRAS/448/2210/table4Details of the X-ray sources with catalogue matchesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTriggerIceCube trigger field numberobs.fieldintSourceSource number within the trigger fieldmeta.idintSimbadSimbad match source namemeta.idcharDS? Distance to Simbad matcharcsecpos.angDistancefloatnullableX-rayX-ray match source namemeta.idcharDX? Distance to X-ray matcharcsecpos.angDistancefloatnullableFX? X-ray 0.3-10keV flux (1)1e-16W.m**-2phot.flux;em.X-rayfloatnullableE_FX? Error on FX (upper value)1e-16W.m**-2stat.error;stat.maxfloatnullablee_FX? Error on FX (lower value)1e-16W.m**-2stat.errorfloatnullable