Response of the KM3NeT detector to neutrinos from Fermi bubbles.

R. Coniglione Amsterdam March 2011 From Meng Su, Tracy R. Slatyer, Douglas P. Finkbeiner http ://arxiv.org/abs/ v3 accepted Astrophys.J.724: ,2010 Observation of Fermi LAT Extension 50° in latitude 40° in longitude no spatial and intensity variation in the  spectrum

R. Coniglione Amsterdam March 2011 Consistent with E -2 spectrum Intensity ~ ÷ GeV cm -2 s -1 sr -1

R. Coniglione Amsterdam March 2011 In Meng Su et al. bubbles are due to relativistic CR electrons that produce gamma through IC process

R. Coniglione Amsterdam March 2011 “We show below that a cosmic ray population can explain these structures” ……… “…Finally, we predict that there should be a region of extended, TeV  radiation surrounding the Galactic nucleus on similar size scales to the GeV bubbles with an intensity up to E -2 F  (TeV) ~10 -9 TeV cm -1 s -1 sr -1 which should make an interesting target for future  -ray studies. Likewise, the region is a promising source for future, Northern Hemiphere, km3-volume neutrino telescope: we estimate (assuming a  =2.0 proton spectrum cut-off 1 PeV)…. The expected neutrino flux for one bubble is E -2 F (TeV) ~ GeV cm -1 s -1 sr -1 * 0.34 sr / 2.5 ~ GeV cm -1 s -1 From M. Crocker and F. Haronian Phys. Rev. Lett. 106 (2011) Gamma flux Single bubble solid angle From  spectrum to spectrum

R. Coniglione Amsterdam March 2011 Bubbles spatial extension Visibility for a detector located at the Capo Passero latitude North 68% South 89% From Fermi LAT observation Extension 50° in latitude 40° in longitude

Monte Carlo simulations DETECTOR Number of structures -> 154 towers Number of storeys/structure -> 20 Distance between floors -> 40 m Distance between towers -> 180 m Bar length -> 10m PMT -> 8”, 35%QE, 47 kHz opt. back. Number of PMT/floor -> 6 (4 dh + 2 dd 45°) Hexagonal lay-out CODES & inputs ANTARES codes (Aart strategy) Capo Passero parameters (depth, latitude, absorption length…) Discovery flux calculation -> Minimization of MDP (cuts on , Nfit (…), Rbin)

R. Coniglione Amsterdam March 2011 North  = -15° RA = 243° R =19° South  = -44° RA = 298° R =19 ° Neutrino generation homogeneous in a circular region around fixed points

R. Coniglione Amsterdam March 2011 Discovery flux - E -2 spectrum one block of 154 DU

R. Coniglione Amsterdam March 2011 Discovery flux cut off 100 TeV one block of 154 DU

R. Coniglione Amsterdam March 2011 Discovery flux cutoff 50 TeV one block of 154 DU

R. Coniglione Amsterdam March 2011 Energy spectra Signal with cuts Signal atm with cuts atm  Source spectrum E -2  Source intensity GeV cm -2 s -1 (discovery flux 5  50% one year) Analysis in between point-like and diffuse flux analysis

R. Coniglione Amsterdam March 2011 Energy spectra Signal with Nfit >47 Signal atm with NFit >47 atm  Source spectrum E -2 exp-(E  /100 TeV)  Source intensity GeV cm -2 s -1 (discovery flux 5  50% one year)

R. Coniglione Amsterdam March 2011 Sky view 1 block of 154 DU E -2 Spectrum Source intensity GeV cm -2 s -1 1 year observation time Significance north+south ~ 10 sigma

R. Coniglione Amsterdam March 2011 Energy Selectors  To improve the discovery potential some variables sensitive to the neutrino energy have been tested  Nfit  number of hits in the final fit  R  average number of hits per OM  NOM  number of OM in the final fit  NOM 1p.e.  number of OM in the final fit with at least one hit with amplitude higher than1 p.e.  NOM 1.5 p.e.  number of OM in the final fit with at least one hit with amplitude higher than1.5 p.e.  ……….  2.5 p.e.  all the hits with charge lower than 2.5 p.e. are removed before the fit procedure

R. Coniglione Amsterdam March 2011 Energy Selector variable Discovery 5  2 years E -2 Discovery 5  E -2 & Cutoff 100 TeV Nfit R (hit repetition) NOM NOM 1p.e NOM 1.5 p.e NOM 2 p.e NOM 2.5 p.e p.e. threshold

R. Coniglione Amsterdam March 2011 Analysis and results very sensitive to the shape of the neutrino spectrum Good chance to see neutrinos from Fermi Bubbles More precise theoretical predictions are needed. Conclusions

R. Coniglione Amsterdam March 2011 SPARE

R. Coniglione Amsterdam March exp-(E /Ec) disc 5s 50% 2years -> exp-(sqrt(E /Ec)) disc 5s 50% 2years -> Ec = 100 TeV