seeking the sources of high-energy neutrinos with swift · •3"upper limits on the flux for a...

12
Azadeh Keivani Penn State University Collaborators: Doug Cowen, James DeLaunay, Derek Fox, Jamie Kennea, Gordana Tešić, Colin Turley (Penn State University) Phil Evans, Julian Osborne (University of Leicester) Frank Marshall (NASA GSFC) Seeking the Sources of High-Energy Neutrinos with Swift TeVPA 2017 Center for Cosmology and AstroParticle Physics The Ohio State University August 9

Upload: others

Post on 03-Jul-2020

0 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

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

Page 2: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

Swift SearchesforEMcounterparttoIceCubeneutrinos

• Swift follow-upcampaigns:• PowerfulapproachtosearchforluminousEMcounterpartstohigh-energycosmicneutrinos

• Setusefulconstraintsonassociatedtransients• UseXRTandUVOTtelescopes

• UnderourNASASwift Cycle12GuestInvestigatorprogram

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

Page 3: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

• 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

Page 4: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

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

Page 5: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

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

Page 6: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

• 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

8/9/17 AzadehKeivani(PennState)- TeVPA2017 6

Swift ObservationsofIceCube-160731A

Page 7: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

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

8/9/17 AzadehKeivani(PennState)- TeVPA2017 7

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

Page 8: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

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.

Page 9: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

• 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

Page 10: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

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

8/9/17 AzadehKeivani(PennState)- TeVPA2017 10

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

Page 11: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

• 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

Page 12: Seeking the Sources of High-Energy Neutrinos with Swift · •3"upper limits on the flux for a typical AGN spectrum placed •30%-65% of X-ray afterglows of Swift-detected GRBs would

• 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

8/9/17 AzadehKeivani(PennState)- TeVPA2017 12

ConclusionsandProspects