Azadeh Keivani

Penn State University Collaborators:

DougCowen,JamesDeLaunay,DerekFox,JamieKennea,Gordana Tešić,ColinTurley(Penn State University)PhilEvans,JulianOsborne(University of Leicester)

FrankMarshall(NASA GSFC)

SeekingtheSourcesofHigh-EnergyNeutrinos

withSwift

TeVPA 2017Center for Cosmology and AstroParticle Physics

The Ohio State UniversityAugust9

Swift SearchesforEMcounterparttoIceCubeneutrinos

• Swift follow-upcampaigns:• PowerfulapproachtosearchforluminousEMcounterpartstohigh-energycosmicneutrinos

• Setusefulconstraintsonassociatedtransients• UseXRTandUVOTtelescopes

• UnderourNASASwift Cycle12GuestInvestigatorprogram

8/9/17 AzadehKeivani(PennState)- TeVPA2017 2

• Twohighenergyreal-timepublicstreams:• HighEnergyStartingEvents(HESE)

• SinceApril2016• Six eventssofar• Onlytrack-like

• ExtremelyHighEnergy(EHE)• SinceJuly2016• Four eventssofar• Track-like

• Distributevia:• AstrophysicalMultimessengerObservatoryNetwork(AMON)• Gamma-rayCoordinatesNetwork(GCN)• https://gcn.gsfc.nasa.gov/amon.html

• TriggeredSwift follow-upobservationsof:• IceCube-160731A• IceCube-161103A• IceCube-170312A• IceCube-170321A

8/9/17 AzadehKeivani(PennState)- TeVPA2017 3

CurrentIceCubepublicreal-timestreams

JamesDeLaunay’s Talk

Events Stream Charge(p.e.)

Signalness* R50Rev0

R90Rev0

R50Rev1

R90Rev1

IceCube-160731A HESE/EHE 15814 0.91 0.42° (HESE)0.17° (EHE)

1.23°(HESE)

0.35° 0.75°

IceCube-161103A HESE 7546 0.30 0.42° 1.23° 0.65° 1.1°

IceCube-170312A HESE 8858 0.78 0.42° 1.23° - <0.5°

IceCube-170321A EHE 6214 0.28 0.32° - - 1.2°

8/9/17 AzadehKeivani(PennState)- TeVPA2017 4

*Signalness forEHEisanestimateprobabilitythattheeventisduetoanastrophysicalneutrino.Itiscalled"signal_trackness" forHESEreflectingthelikelihoodthattheneutrinobeingbothsignal-likeandtrack-like.

IceCubeEventProperties

8/9/17 AzadehKeivani(PennState)- TeVPA2017 5

• Priority1TOO• Mosaicof19pointingsforHESEand

7pointingsforEHE• AutomatedanalysisofXRTdata:

softwareatUniversityofLeicester,PhilEvans

Events SwiftStart Obs LatencyIceCube-160731A ~1hrIceCube-161103A ~5hrsIceCube-170312A ~2hrsIceCube-170321A ~6hrs

Swift ObservationsofIceCubeEvents

• Observationstaken3.9to46.5ks aftertheneutrinotrigger

• Covered2.1deg2

• Covered64.2%oftheneutrinorevisedr90errorregion

• Collected~ 800sperfieldofPCmodedatapertile

• SixX-raysourcesweredetected• KnownX-rayemitters• CatalogobjectswithexpectedX-rayemission

• Fluxupperlimits(0.3-10KeV):• 4.3x10-13ergcm-2 s-1foratypicalAGNspectrum(NH=3x1020cm-2,𝛾=1.7)

• 3.1x10-13ergcm-2 s-1foroverlappedareas

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Swift ObservationsofIceCube-160731A

Events Total Obs Time(ks)

PointingCoverage(deg2)

NeutrinoCoverage(rev1r90 errorregion)

Timepertile(s)

Src#

3𝜎 flux UL(ergcm-2 s-1)

IceCube-160731A 42.6 2.1 64.2 % ~ 800 6 4.3x10-13

IceCube-161103A 17.7 2.1 68% ~ 150- 250 4 1.2x10-12

IceCube-170312A 47.6 2.1 82.3% ~ 800 5 4.1x10-13

IceCube-170321A 14.1 0.5 22.1% ~ 900 2 1.5x10-13

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Swift XRTObservations

GCNcirculars:• https://gcn.gsfc.nasa.gov/gcn3/19747.gcn3• https://gcn.gsfc.nasa.gov/gcn3/20125.gcn3• https://gcn.gsfc.nasa.gov/gcn3/20890.gcn3• https://gcn.gsfc.nasa.gov/gcn3/20964.gcn3

Events Filterused Exposure(s)

Limitingsensitivity(mag)

IceCube-160731A U 420 18.9IceCube-161103A U(16pointings)+

UVW1 (3pointings)250 18.9

IceCube-170312A U 110 18.9IceCube-170321A U 922 18.9

8/9/17 AzadehKeivani(PennState)- TeVPA2017 8

Swift UVOTobservations

NotransientsourceswerediscoveredinanyofthesesearchesassociatedwiththeIceCubetrigger.

• Alibraryof192Swift XRTlight-curves

• Power-lawfits

• AssumeneutrinodetectiontimetobecoincidentwiththeGRB

• MedianX-rayafterglow,80%and50%confidenceranges

• X-rayfluxlimitsforneutrinoeventsaveragedoveralltilesofeachmosaicpointing

• Thefluxlimit:the#ofsourcephotonstoyieldanexcessoverbackgroundwithp-value<10-6 inasinglesourceaperture

• SuchexcessesoccurviaPoissonfluctuationofthebackgroundin~10%(4%)of19(7)-tileobservingcampaigns

8/9/17 AzadehKeivani(PennState)- TeVPA2017 9

4 6 8 10 20 40 60 Time after Neutrino (ks)

10-13

10-12

10-11

FX (

erg

cm

-2 s

-1)

4 6 8 10 20 40 60 10-13

10-12

10-11

160731A 161103A

170312A 170321A

GRBX-rayafterglow

P𝛥t,x oftheX-rayafterglowsofSwift-detectedGRBswouldberecoveredbythefollow-upcampaigns,assumingtheburstoccurredwithintheFOVoftheobservations

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Events P𝛥t,xIceCube-160731A 65%IceCube-161103A 30%

IceCube-170312A 55%IceCube-170321A 43%

GRBX-rayafterglowconstraints

4 6 8 10 20 40 60 Time after Neutrino (ks)

10-13

10-12

10-11

FX (

erg

cm

-2 s

-1)

4 6 8 10 20 40 60 10-13

10-12

10-11

160731A 161103A

170312A 170321A

• PrecursortotheIceCube-160731A

• Nodetectionin±1ks ofT0• UseAGILE-GRIDAutomaticQuickLookprocedureover48-hrstimebins:• Excess>100MeV• T0-1.8<T<T0-0.8days• Consistentwithν errorregion• Post-trialsignificance~4𝜎• AGLJ1418+0008

• Fermi-LAThadalowexposureduringtheAGILE𝛾-raytransient

• DedicatedSwift ToO dataà noX-raycounterparts

• CheckSwift BATdataforpossible𝛾-raycounterparts

8/9/17 AzadehKeivani(PennState)- TeVPA2017 11

AGILE’sCandidate𝛾-RayPrecursortoIceCube-160731A

arXiv:1707.08599

• FourSwift follow-upcampaignssofarseekingtoidentifytransientorvariableX-rayorUV/opticalsourcesthatmightbeassociatedwithIceCubehigh-energycosmicmuonneutrinos

• Observationscovered64.2%,68.0%,82.3%and22.1%ofthe90%containmentregionsforthefourneutrinoevents

• NocompellingcandidateX-rayorUV/opticalcounterpartforanyoftheeventsidentified

• 3𝜎 upperlimitsonthefluxforatypicalAGNspectrumplaced• 30%-65%ofX-rayafterglowsofSwift-detectedGRBswouldberecoveredbythefollow-upcampaignsoftheseneutrinos

• Apaperinpreparationwithupperlimitsconsideringmoresourcescenarios:blazars andsupernovae

• PlantocontinueSwift follow-upobservationsofIceCubehigh-energyneutrinosatarateofroughlyfourcampaignsperyear

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ConclusionsandProspects