Neutrinos from the Milky Way. 18th Symposium on Astroparticle Physics in the Netherlands Erwin Visser

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1 Neutrinos from the Milky Way 18th Symposium on Astroparticle Physics in the Netherlands Erwin Visser

2 Outline How are these neutrinos produced? Why look for them? How to look for them The ANTARES neutrino telescope ANTARES sensitivity th APP symposium - Erwin Visser 2/21

3 The Milky Way NASA NASA Neutrinos NASA th APP symposium - Erwin Visser 3/21

4 Neutrino signal from the Milky Way CR p / He / Fe p th APP symposium - Erwin Visser 4/21

5 Neutrino signal from the Milky Way CR p / He / Fe p π +/- π 0 ϒ ϒ µ +/- ν µ ν ν e +/- µ e th APP symposium - Erwin Visser 5/21

6 Neutrino signal from the Milky Way CR p / He / Fe p π +/- π 0 ϒ ϒ µ +/- ν µ ν ν e +/- µ e Guaranteed signal Only limit known: (Amanda-II) IceCube excess could be caused by CR interactions th APP symposium - Erwin Visser 6/21

7 Estimating the flux Theoretical models Using experimental observations Need a lot of assumptions Matter density Cosmic ray flux Magnetic field configuration th APP symposium - Erwin Visser 7/21

8 Estimating the flux Theoretical models Need a lot of assumptions Matter density Cosmic ray flux Magnetic field configuration Using experimental observations CR p π +/- π 0 ϒ ϒ µ +/- ν µ ν ν e +/- µ e th APP symposium - Erwin Visser 8/21

9 Estimating the flux Theoretical models Need a lot of assumptions Matter density Cosmic ray flux Magnetic field configuration Using experimental observations CR p π +/- π 0 ϒ ϒ µ +/- Fermi satellite measures γ-rays: E = 3.4 GeV ν µ ν ν e +/- µ e Photons th APP symposium - Erwin Visser 9/21

10 Estimating the flux Theoretical models Need a lot of assumptions Matter density Cosmic ray flux Magnetic field configuration Using experimental observations CR p π +/- π 0 ϒ ϒ µ +/- E = 10.4 TeV ν µ ν ν e +/- µ e Neutrinos th APP symposium - Erwin Visser 10/21

11 The ANTARES neutrino telescope Cherenkov light from muon γ č 43 µ +/- ν µ GC: 68% visibility th APP symposium - Erwin Visser 11/21

12 The background 1. Atmospheric neutrinos Irreducible background 2. Atmospheric muons Reducible background Consider high quality events ν µ µ CR CR Earth Earth th APP symposium - Erwin Visser 12/21

13 Reducing atmospheric muon background Use UPgoing events ANTARES Data MC: atm. muons MC: atm. neutrinos th APP symposium - Erwin Visser 13/21

14 Reducing atmospheric muon background PRELIMINARY ANTARES Data MC: atm. muons MC: atm. neutrinos Make use of the event topology th APP symposium - Erwin Visser 14/21

15 Neutrino fluxes In GC direction ν µ CR Earth Use high energy events th APP symposium - Erwin Visser 15/21

16 My analysis Model independent approach Determine background using 5 background regions th APP symposium - Erwin Visser 16/21

17 My analysis Need a sufficient angular resolution to distinguish events from the background regions Check systematics of background regions Optimise reconstruction quality and R parameter to find optimum MRF Compare number of events in signal region with average in background regions th APP symposium - Erwin Visser 17/21

18 Angular resolution Angular resolution median of the angle between true neutrino track and reconstructed muon Sub degree angular resolution is good for a neutrino telescope th APP symposium - Erwin Visser 18/21

19 Systematics of background regions Loose cut applied Region # of events ± ± ± ± ± th APP symposium - Erwin Visser 19/21

20 ANTARES sensitivity N signal N background = 1.09 = PRELIMINARY NoDrift_simple NoDrift_advanced Drift AMANDA-II limit scaled ANTARES sensitivity ( ) th APP symposium - Erwin Visser 20/21

21 Conclusions and outlook Guaranteed signal Galactic plane is also an interesting region Model independent approach Background obtained from data using background regions A difficult measurement ANTARES can only set a limit Need bigger neutrino telescope for detection (KM3NeT) th APP symposium - Erwin Visser 21/21

22 Backup th APP symposium - Erwin Visser

23 References to theoretical papers th APP symposium - Erwin Visser

24 Sources th APP symposium - Erwin Visser

25 Visibility th APP symposium - Erwin Visser

26 The Antares detector th APP symposium - Erwin Visser

27 Detector performance Angular resolution: cumulative distribution of the angle between the true neutrino track and the reconstructed muon event that passes the selection criteria (assuming E -2 spectrum). Acceptance: (neutrino) effective area, i.e. the equivalent area of a 100% efficient detector, as a function of the neutrino energy (three different declinations band considered). The median is % of the events are reconstructed better than th APP symposium - Erwin Visser

28 Full sky search th APP symposium - Erwin Visser

29 Matter density in the galaxy # particles / cm th APP symposium - Erwin Visser

30 Column density # particles / cm th APP symposium - Erwin Visser

31 Theoretical models C R p π 0 Assumption 1: cosmic ray flux ϒ ϒ π +/- µ +/- ν µ ν ν e +/- µ e Assumption 2: matter density Assumption 3: magnetic field th APP symposium - Erwin Visser

32 Theoretical models C R p π 0 Assumption 1: cosmic ray flux ϒ ϒ π +/- µ +/- Simplest model ν µ ν ν e +/- µ e Simple CR parameterisation Neglect magnetic field Advanced model + Take CR composition into account Drift model + Magnetic field gives drift of CRs to GC Assumption 3: magnetic field th APP symposium - Erwin Visser