Galactic template neutrino searches - PowerPoint Presentation

1. Galactic template neutrino searchesMaurizio Spurio, maurizio.spurio@unibo.it Università di Bologna e INFN1M. Spurio - Galactic template neutrino searches

2. Propagation induces accidentsM. Spurio - Galactic template neutrino searches2…thank you organizers to remind usLe Corniaud(Colpo grosso ma non troppo ) 

3. Summaryn diffuseHints for neutrinos from the GalaxyData samples and detectorsSearch templatesGalactic Diffuse Emission Galactic centerFermi Bubbles(stacking searches) Perspectives M. Spurio - Galactic template neutrino searches3

4. Why Galactic templatesGalactic CR sourcesCR propagationBoron-to-Carbon ratio Diffuse galactic gamma flux Fermi-LAT, H.E.S.S., Milagro, HAWC, (LHAASO, CTA)Model templates Dense matter regions boost g and n fluxesModels can be tuned to g/CR observationsNeutrinos allow testing CRs propagationM. Spurio - Galactic template neutrino searches4AMS02, PRL 117, 231102 (2016)LAT, ApJ 750:3 (2012)

5. The rationale on “template” neutrino searches Cosmic neutrinos are not “background” freeAtmospheric neutrinos represent an irreducible, almost isotropic, backgroundAtmospheric muons can be removed by selecting upgoing events, or by “vetoing” techniques that reduce Veff;Background  (angular resolution )2Cosmic n’s harder than atmospheric neutrinosUnbinned likelihood maximization methods are usually used to identify cosmic neutrinosThe optimization of the signal-to-noise ratio depends on the expected signal. A template, i.e., (, En) map, can improve the sensitivityThe optimization is in Probability Density Functions (PDF) embedded in the likelihood SK, PRD 94, 052001 (2016) Cosmic n’sM. Spurio - Galactic template neutrino searches5

6. Hints for a possible cosmic galactic component (1)Galactic ?Southern skyIceCube HESEarXiv:2011.03545 (Nov. 2020)Possibility for Northern telescopes the to test Galactic regionsMS, PRD90:(2014)103004M. Spurio - Galactic template neutrino searches6

7. Hints for a possible cosmic galactic component (2)Galactic component ?<60 TeVSouthern skyIceCube cascade eventsApJ:886:12 (2019) arXiv:1907.06714v1M. Spurio - Galactic template neutrino searches7

8. Hints for a possible cosmic galactic component (3)ANTARES tracks and cascadesApJ:853:L7 (2018)tracksshowersM. Spurio - Galactic template neutrino searches8

9. Summaryn diffuseHints for neutrinos from the GalaxyData samples and detectorsSearch templatesGalactic Diffuse Emission Galactic centerFermi Bubbles(stacking searches) Perspectives Tracks (nm CC)See: Rosa Coniglione talkShowers (ne CC+nx NC)See: Zhan Dzhilkibaev talkM. Spurio - Galactic template neutrino searches9

10. Data samples and detectorsIceCube @ South PoleANTARES @ Mediterranean SeaM. Spurio - Galactic template neutrino searches10

11. ANTARES, ApJ 760:53 (2012)Tracks in IceCube and ANTARES IceCube Phys. Rev. Lett. 124, 051103 (2020)SouthANTARES, E-2ANTARES, E-3M. Spurio - Galactic template neutrino searches11Detector sensitivity depends on the assumed energy spectrum for signalSee: Giulia Illuminati and Rosa Coniglione talks

12. IceCube En<100 TeV from Southern sky employing vetoDifferential discovery potential at d= -60° forLow-Energy Starting Events (LESE, yellow)Starting TeV Events (STeVE, blue), the combined selection (LESE+STeVE) (red)ANTARES (black)Astrop.Phys:116 (2020), 102392 M. Spurio - Galactic template neutrino searches12

13. Showers in IceCube2428 days of IceCube livetime1980 are identified as cascades. ApJ:886:12 (2019) arXiv:1907.06714v1M. Spurio - Galactic template neutrino searches13Direction of shower events less precise, but the ne channel less affected by atmospheric neutrino background

14. Summaryn diffuseHints for neutrinos from the GalaxyData samples and detectorsSearch templatesGalactic Diffuse Emission Galactic centerFermi Bubbles(stacking searches) Perspectives M. Spurio - Galactic template neutrino searches14

15. n-mapA. CR- g and n from the Galactic planeGalactic Diffuse Emission (GDE) is guaranteed by hadronic interactions of CRs with the ISMGDE includes contribution of p0 decay, IC, bremsstrahlung.GALPROP is an example of successful attempts to model the diffuse Galactic g-ray componentThe DRAGON code solves the particle transport equations The KRA “gamma” (g)-model assumes a spatial dependent diffusion coefficient  hardening of the CR spectrum for a decreasing Galactocentric radiusM. Spurio - Galactic template neutrino searches15KRA-g Gaggero+, PRL 119, 031101 (2017)

16. ANTARES, no templateSearch for an excess of HE muon neutrinos on an extended region of solid angle DW=0.145 sr centered in the Galactic origin (|l| <30o, |b| <4o) Track events from data period 2007-2013 No template or model tested (extended source)First upper limit set, for different spectral indexesANTARES, PLB 760 (2016), arXiv:1602.03036 M. Spurio - Galactic template neutrino searches16

17. IceCube, 3 templatesIceCube, ApJ 849:67 (2017) arXiv:1707.03416 Three templates for Galactic emission testedFermi-LAT p0-decay, ApJ, 750:3(2012)KRA-g50 ApJL, 815, L25(2015), Ingelman & Thunman (hep-ph/9604286).Likelihood contains information in the signal part about the templatesRed: IceCube 90% C.L limits on the three-flavors n (1:1:1 flavor ratio assumption) with respect to KRA-g50 model (gray band).Blue: ANTARES limit in blue, no templateANTARES, PRD 96, 062001 (2017) arXiv:1705.00497ANTARES, KRA-g5,g50 templates90% C.L. limit at the same level of IceCube, but on a different Galactic region M. Spurio - Galactic template neutrino searches17

18. IceCube and ANTARESSouth NorthANTARES+IceCube ApJL 868:L20 (2018)M. Spurio - Galactic template neutrino searches18

19. ANTARES and IceCube7years of IceCube tracks + 10 years of ANTARES tracks and showers using a likelihood ratio test.Sensitivities below the expected signalThe max-likelihood estimate yields a non-zero diffuse Galactic neutrino flux for both KRA-g models (p-values of 30%)As neither of these results is statistically significant, 90% CL upper limits were placedANTARES+IceCube ApJL 868:L20 (2018)M. Spurio - Galactic template neutrino searches19

20. IceCube showersIceCube ApJ:886:12 (2019) arXiv:1907.06714v1The analysis with IC showers has ∼30% better sensitivity to KRA-g5. Lower background level from atmospheric muons and atmospheric neutrinosEmission following the KRA-g5 presents the most significant p-value (2.0σ) and best-fit flux of 0.85xF.M. Spurio - Galactic template neutrino searches20

21. B. The Galactic centerH.E.S.S. Nature 531, 476 (2016) arXiv:1603.07730M. Spurio - Galactic template neutrino searches21

22. ANTARES+IceCube ApJ 892:92 (2020)Neutrino predictions/U.L.U.L. ANTARES + IceCubeH.E.S.S. Nature 531, 476 (2016) IceCube ApJ:886:12 (2019)U.L. IceCube showersx 10-11M. Spurio - Galactic template neutrino searches22ss= different hypotheses of source extension

23. C. Fermi BubblesShapes of the Fermi Bubbles’ templates observed at high and low latitudes by Fermi-LAT. The hourglass shape used in the analysis is indicated in blueANTARES PoS(ICRC2017)1001 On- and off-zones in Galactic coordinates. The color code shows the visibility for events in the shower analysis.M. Spurio - Galactic template neutrino searches23

24. Fermi Bubbles: U.L.M. Spurio - Galactic template neutrino searches24ANTARES PoS(ICRC2017)1001 IceCube ApJ:886:12 (2019)

25. The future: KM3NeTKM3NeT: PoS(ICRC2019)956M. Spurio - Galactic template neutrino searches25

26. The future: GVDZh.-A. Dzhilkibaev (this meeting)M. Spurio - Galactic template neutrino searches26

27. Galactic Diffuse from SNR and XRB-CRsThe predicted diffuse Galactic neutrino spectrum from SNR-CRs and XRB-CRs with joint upper limits from ANTARES and IceCube (Aartsen et al. 2017) using the DRAGON code. A. J. Cooper+, High-energy Cosmic Ray production in X-ray Binary Jets, MNRAS 493 (2020)M. Spurio - Galactic template neutrino searches27KM3NeT+GVD

28. ConclusionsM. Spurio - Galactic template neutrino searches28Galactic neutrinos are expected, either from sources and CR propagation  templatesHints from observation of a diffuse flux of cosmic neutrinosTemplates provide spatial and energy distribution of cosmic n’sAdvantage: increases of the signal to noise ratio and sensitivitiesDrawback: the results are more model-dependent Although the IceCube instrumented volume is ANTARES, their sensitivities for track and showers events are almost equivalent for a large fraction of the Galactic planeGalactic Plane: close to a possible signalIndividual experimental results, combined analysesFirst indication (at level of 2s) of agreement with the KRA-g5Near future: improvement of knowledge form g-rays (LHAASO, CTA)New data from IceCube and ANTARESNew experiments: IC-Gen2, GVD and KM3NeT