ComPair and future perspec2ves in MeV Gamma-ray astronomy · Alexander Moiseev SciNeGHE-2016 21 AMEGO • We already realized that the use of GLAST and other ﬂown instruments heritage

ComPair

ComPairandfutureperspec2vesinMeVGamma-rayastronomy

AlexanderMoiseevSciNeGHE-2016 1

•  WhyMeVrange?•  Whatscienceisthere?–thankstoMarcoTavaniforexcellent

coverageofthescienceobjecJves•  Instrumentconcept–ComPair•  Futureimprovement–AMEGO•  Moredreams…

AlexanderMoiseevCRESST/NASA/GSFCandUniversityofMaryland,CollegePark,onbehalfoftheComPairscienceteam(NASA/GSFC,NRL,UCSC,WashUandClemsonU)

ComPairWhydowewanttolookintheMeVRange?

Guaranteeddiscoveryspace!AlexanderMoiseevSciNeGHE-2016 2

ComPair

•  MeV:theleastexploredregionoftheelectromagne;cspectrum•  ComPairwillprovideahugeleapinsensi2vityandbreakthroughscience

capability•  ComPairwillcon2nueFermiLATexplora2onofgamma-rayskyatlower

energyin“impossible”energyrange,heavilybasingonitsheritageAlexanderMoiseevSciNeGHE-2016 3

ScienceDriverforComPair–Guaranteeddiscoveryspace

ComPair

4

EGRETAll-SkyMapAbove100MeV

~200SourcesDetected

Credit:EGRETTeamCredit:NASA/DOE/FermiLATCollaboraJon

Fermi-LATAll-SkyMapAbove1GeV

~3000SourcesDetected

WhatFermiLAThasdone:High-energygamma-rayskymapaQer8yearsofopera;on

AlexanderMoiseevSciNeGHE-2016

ComPair

5

COMPTELAll-SkyMap1-30MeV

TensofSourcesDetectedCredit:COMPTELCollaboraJon

WhatwecanexpectfromComPair:


ComPair

ScienceObjecJves:ExtremeAstrophysics

•  UnderstandinghowtheUniverseworksrequiresobservingastrophysicalsourcesatthewavelengthofpeakpoweroutput.

–  PeakpoweriscrucialforestablishingsourceenergeJcs.–  Fermi-LAT,NuSTAR,andSwi(BAThaveuncoveredsource

classeswithpeakenergyoutputinthepoorlyexploredMeVband.

–  ComPairscienceobjecJvesfocusoncasesofextremeastrophysics:

•  HighmaberdensiJes

•  StrongmagneJcfields•  Powerfuljets.

6

ComPair

A cri;cal energy band - Spectral features such as breaks,turnovers, cutoffs, and temporal behavior, which are criJcal todiscriminatebetweencompeJngphysicalmodels,occurwithintheMeVenergyrange.

MeVBlazars•  Amongthemostpowerfulpersistent

sourcesintheUniverse•  Largejetpower,easilylargerthan

accreJonluminosity•  Hostmassiveblackholes,near109solar

massesormore•  Detecteduptohighredshig•  EvoluJonofMeVblazarsisstronger

thananyothersourceclass–i.e.maximumdensitymightbeveryearlyon

•  ComPairwilldetect>500MeVblazars–  ~100atz>3


ComPair

J.S.Perkins,SPIE2016

ScienceExample:ExtremePhysicsofCompactObjects

•  CompactobjectswithkeyenergyfeaturesintheMeVrangeinclude:–  Magnetars-strongestmagneJcfieldsin

theUniverse(notethattheydon’tpeakintheMeV).

–  Pulsars-neutronstarsrepresentthehighestmaberdensiJespossiblebeforecollapsetoablackhole.

8

Collmar&Zhang,2014

HighmassX-rayBinaryLS5039atsuperiorandinferiorconjuncJon.

SelectedPulsars(200gamma-raypulsarsareknown).

ComPair

•  DoAGNjetsaccelerateprotonstoextremelyhighenergies?–  ProducingPeVneutrinos,UHECRandhighenergygamma-rays

–  MeVrangeiscrucial

9J1653-329acandidatePeVneutrinoemiber(Kraussetal2014)

MeVBlazars/observaJonsandMulJmessengerAstrophysics


ComPairSogGamma-rayPulsars

•  PulsarsseeninhardX-raybutnotbyFermi-LAT,peakliesinMeVband

•  11MeVpulsarsknown–  ExtremelyenergeJcEdot>1036erg

•  Possible“hidden”popula;onofenerge;csoQgammaemi[ngpulsars

10AlexanderMoiseevSciNeGHE-2016

ComPair DiscoverySpace●  Previousinstrumentscoveringthe

1-100MeVrangewereCOMPTEL/OSSEonCGROandIntegralSPI;Fermi-LATisnotwellopJmizedbelow100MeV

●  ~⅓ofFermi-LATsourcesremainuniden;fied!o  ComPairwillprovideabridge

betweenhigh-energygamma-rayandX-rayregimes,helpingtoidenJfyandunderstandtheseobjects

●  Below200MeV,ComPairwilldramaJcallyimprovesensiJvityandopenanewwindowintheEMspectrumleadingtothediscoveryofmanynewsourcesandsourceclasses

>50%ofFermi-LATcatalogsourceshaveapeakbelowtheFermi-LATband.

11

ComPairNewAstronomy:GravitaJonalWavesandNeutrinos

•  MulJmessengerAstrophysics–studyingtheUniverseusinghighenergyneutrinosandgravitaJonalwaves–  NeutrinosareproducedonlyonlyinregionswithextremeparJcle

acceleraJon–  (Detectable)GravitaJonalwavesareproducedinregionswith

enormousenergyrelease–  Gamma-rayobservatoriesarethemostnaturalpathtoconnecJngthis

“newastronomy”toknownastrophysicalobjects

12AlexanderMoiseevSciNeGHE-2016CourtesyofJulieMcEnery

ComPair MissionGoals•  Field-of-view:wide-field-monitorthewholegamma-raysky.

•  EnergyRange:200keV→500MeV

•  SensiJvity:Atleast10JmesbeberthanCOMPTELat~1MeV

•  AngularResoluJon:3-5JmesbeberthanFermi-LATat20-100MeV

13

WhyWide-FieldSurvey?●  Needalong-baselinetodetectpulsars.●  Needtodeterminewhen‘interesJngthingshappen’(glitches,state

changes,…)●  Needtowatchfortransientphenomenon.●  Needtosearchfortheunknown.

ComPair

•  FocusonConJnuumFluxSensiJvity

•  ComPairisanewinstrumentinnamebutnotinheritage.ConceptisbuiltonmaturetechnologyandextensivepriorinstrumentdevelopmentandopJmizaJon.

–  MaximaluseofFermi-LAThardwareheritageandlessonslearned.

–  Modifica;onofamature,wellstudiedmissionconcept(MEGA)

–  Mosttechnicallystraighdorwardapproachforthisenergyrange.

•  AddressescompellingsciencequesJonsandallowsabroadsciencediscoverycapability.

14

ConceptandApproach

ComPair

15

MeV

Challengeandadvantageatthesame;me:idenJficaJonoftheprocess(pair-producJonorCompton)andapplyingappropriateanalysisimprovesthequalityoftheresultsandenablescross-checkinoverlappingenergyrange(assessmentofsystemaJcerrors)

Sensi;vetoboth,pair-produc;onandComptoneventsFrom~0.1-100MeVtwophotoninteracJonprocessescompete:ComptonscaberingandpairproducJoncrosssecJonsintersectat~10MeV


ComPair EventdetecJoninComPair

•  Whatdoweneedtomeasure?–  Comptonevent–measureelectrontrackandenergy,andscabered

gamma-rayposiJonandenergy–  Pairevent–measureelectrontracksandenergy

IntheComPairenergyrange,gamma-raysinteractwithmaberviatwodifferentprocesses:ComptonScaberingatlowenergiesandpairproducJonathigherenergies


ComPair ComPair–ourrealityforMIDEX2016.

•  40-plane0.8mx0.8mdouble-sideSi-striptracker.4towers

•  4-plane3.2XthicklogCsIcalorimeter

•  5-panelplas;cscin;llatorACDwithWLS+SiPMstripreadoutAlexanderMoiseevSciNeGHE-2016 17

ComPair


ComPair

ComPairInstrumentSummary

19InstrumentandSystemDesignStudieshavebeencompleted:ViableMIDEXMission.

EnergyRange 1-200MeV(200keV-500MeV)

EffecJveArea 100-200cm2<10MeV,200-1200cm2>10MeV

AngularResoluJon

~7○at10MeV,~1○at100MeV

EnergyResoluJon

2-5%<20MeV,~12%at100MeV

SolidAngle ~3sr

Dimensions 1mx1mx0.7m(sensiJvevolume)

Mass <1000kg(sciencepayload)

Power <1000w(sciencepayload)


ComPair FromMIDEXtoProbeMo;va;on:performcomprehensiveexplora;onofsub-MeV–hundredsMeVenergyrange,outperformingComPairtoincludetheuniquecapabili;esin:•  Searchforandstudyofnewsourcesandtheirlocaliza;onandiden;fica;onwithhigh

sensi;vity,accuracyandconfidence;performdedicatedstudyofGalac;cCentermorphologywithbelerthan0.1degreeresolu;on

•  Enablingnuclearastrophysics:studyofnucleargamma-raylineswithhighenergyresolu;on,map511keVgamma-rayemissionfromGalac;cCenterwithhighenergyandangularresolu;on

•  Conduc;ngmeasurementofgamma-radia;onpolariza;oninenergyrangefromafrac;onofMeVtoafewtensofMeV

ComPair AMEGO(Expected)

EnergyRange 1-200MeV(200keV-500MeV) 200keV–500MeV(100keV–>5GeV)

EffecJveArea,cm2 20-50cm2<10MeV,~500cm2at200MeV

50-200cm2<1MeV,1,500cm2at500MeV

AngularResoluJon ~120at10MeV,~20at100MeV 10at1MeV,100at10MeV,10a100MeV

EnergyresoluJon 5%at1MeV,10-15%at100MeV 1%at<1MeV,1-2%at5MeV,10%at500MeV


ComPair

•  Nowwehaveabelerideaaboutthecost.ThefirstvisionofAMEGOcanbeclosetotheoriginalComPair,butwithmorealen;ontothenewscience:nuclearlinespectrometryandpolarimetry


AMEGO

•  We already realized thatthe use of GLAST andother flown instrumentsheritage is extremelyhelpful to go through theproposing procedure, sowe suggest to follow theComPairpathtousewell-developedtechnology

ComPair

Tracker:-  4towers.Eachisastackof60double-sided(orthogonalX&Y)0.5mm thick Si-strip detector planes, spaced by 1cm, strippitch0.25mm.NoaddiJonalpassiveconverter!

-  Eachplaneofthetoweris madeof5x5double-sideSi-stripdetectors, 9.5 by 9.5 cm each, with daisy-chained strips ineach direcJon and readout from the sides. Remark: 5 daisy-chainedTBC.Morewouldbebeber

-  Analog signal readout from strips to provide energymeasurement

-  SegmentdesigntobetakenfromComPairdevelopment


ComPairCZTCALORIMETER

•  PosiJonedunderthebobomandatall4sidesoftheTracker

•  Drig-barapproachisused(Bolotnikovetal,BrookhavenNL)•  Segmented calorimeter. 1 segment ismadeof6x6CZTbars,

8x8 mm area (segment area 5cm x 5cm) and 4cm long, tocreate4cmthickcalorimeter(2.5X0)

•  100segmentsareputtogethertomakea10x10towertray


•  ExpectedenergyresoluJonis<1%at662keV,2-3%at5MeV

•  Expected posiJon resoluJon<0.5mm at <1 MeV, 2-3mm at 5MeV

Singlesegment

ComPair


Energyresolu;onforCZTdriQbardetector

CourtesyofA.Bolotnikov

ComPair


CsICALORIMETER

•  TheCsI(Tl)calorimeterdesignissimilartothatofFermi-LATandComPair.

•  Consistsof6planesof1.5cmx1.5cmcrosssecJonCsIlogs,witheachlogreadoutfrombothsidesbySiPM.ThelogsintheplanesarearrangedalternaJvelyalongXandYaxis.

•  Thetotaldepthofthecalorimeteris~5X0

ComPair


Abitofdreaming…..tohappen

ComPair CodedApertureMask

Deployablemast

CAM

•  CAMcanbesetatdifferentdistancefromAMEGO•  Takesawaysmallsolidanglenottobeinconflictwithscanning

observa;ons–sourcelocaliza;onwithpoin;ngmode•  IfsetclosetoAMEGO,worksasacollimatorformapping•  Galac;cCenterobserva;onswithPSF<1’AlexanderMoiseevSciNeGHE-2016 27

CAM

Launchandspectroscopy

posi;on

Sourcedetec;onposi;on

3-4m

ComPair

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COMPTEL AlexanderMoiseevSciNeGHE-2016 28

ComPair

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COMPTEL 29AlexanderMoiseevSciNeGHE-2016

ComPair

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COMPTEL AMEGOAlexanderMoiseevSciNeGHE-2016 30

ComPair

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COMPTEL AMEGOAlexanderMoiseevSciNeGHE-2016 31

AMEGO-CAM

Documents

ComPair and future perspec2ves in MeV Gamma-ray astronomy · Alexander Moiseev SciNeGHE-2016 21 AMEGO • We already realized that the use of GLAST and other ﬂown instruments heritage