Astronomy session: a summary R. Coniglione, INFN - Laboratori Nazionali del Sud

Astronomy session Detector optimization: Kooijman for De Jong, Sapienza FoM for Galactic sources: Sapienza, Coniglione, Leisos The reference detector: 2 blocks of 310 strings (20 floors/string 40m distant) with MultiPMT. Distance between strings 100m. Total volume 3.8 km3 MC inputs: same (WPD document) Codes: Sirene, HOU software, ANTARES code modified for KM3NeT (LNS code)

P. Kooijman for M. de Jong Sirene Sirene is yet another program that simulates the detector response to muons and showers It uses a general purpose collections framework for PDF/CDF tables allows for optimisation of accuracy and speed of interpolations facilitates I/O It runs about 10 x faster than km3 NO reconstruction – no search analysis Analysis at trigger level number of events with ≥ 5 L1s from RXJ1713 per year (Kelner spectrum) L1 corresponds to two (or more) hits on same optical module within 10 ns procedure scaling factor applied to absorption length (0.9, 1.0, 1.1, 1.2) vary horizontal spacing 80‒130 m and vertical spacing 30‒50 m determine optimal spacing for each absorption length dependence of performance figure on scaling factor

Module = Building block = smallest detector with optimal efficiency P. Kooijman for M. de Jong Scaling Factor: Absorption length wrt Km3 “standard” absorption length Number of lines  In a block events scaled to 640 lines (20 floors) Number of floors  Reduced floors gives more lines, 120 line blocks scaling factor scaling factor events / year = number of lines in a block number of floors Building block = smallest detector with optimal efficiency 80<Lines<120 and 15<floors<19

Example There is a clear maximum P. Kooijman for M. de Jong Example events / year horizontal spacing [m] scaling factor 1.1 vertical spacing [m] vertical spacing horizontal spacing There is a clear maximum For this scaling factor: 100m horizontal and 34-38 m vertical

Dependence on absorption length P. Kooijman for M. de Jong Dependence on absorption length optimal detector events / year scaling factor For each absorption length optimize the detector There is a clear linear dependence

From detector optimization with SIRENE P. Kooijman for M. de Jong Conclusions From detector optimization with SIRENE Typical numbers: Blocks: 80-120 lines Floors: 14-18 Horizontal distance: 80-110 m Vertical distance: 35-40 m Numbers vary within these limits for different absorption length Optimizing at each absorption length yields a linear dependence of number of events on absorption length.

P. Sapienza The SNR RXJ1713 RXJ1713 Event simulation performed with Antares code adapted for km3 detector Simulation for RXJ1713 with a Kelner spectrum in a flat disk of 0.6° RECO => Fit with a scanning procedure based on a 3°x3° grid plus rotations + Aart strategy Binned and unbinned search analysis values of FoM (years for 5s discovery) and sensitivity

RXJ1713-39.46 sensitivity 1 y – DU distance P. Sapienza RXJ1713-39.46 sensitivity 1 y – DU distance Two blocks of 310 strings 20 multi-PMT/string 40 m distance between multi-PMT Better performance for a 100m string distant detector In one year, if no statistically significant excess will be found, upper limits lower the kelner model can be set Proposed as public plot

P. Sapienza RXJ1713-39.46 5s – DU distance Official result to quote: RXJ1713 5.8 years preliminary and binned Proposed as public plot Binned Significance Years Nsource Nbackground 5sigma 5.8 29.9 26.8 3sigma 2.1 10.1 8.5 Unbinned estimated 100 m is a good distance for galactic sources Unbinned calculations provide a rather good improvement of the FoM

RXJ1713-39.46 labs dependence L*abs = 1.1 Labs L*abs = 1 Labs P. Sapienza RXJ1713-39.46 labs dependence L*abs = 1.1 Labs String Distance (m) Nsource/year Nback/year F.O.M. 90 5.30 37.2 6. 100 5.40 34.2 5.6 130 5.10 24.1 6 10% difference in Labs-> Difference of about 5% between FOM Same string distance optimization at different Labs L*abs = 1 Labs String distance (m) Nsource/year Nback/year F.O.M. 90 5.01 34.4 6.3 100 5.04 30.0 5.8 130 4.66 20.9 6.5 Nsource and Nback = number of events in 1° around the source position (no cut applied)

From A. Leisos HOU codes Unbinned search method The unbinned analysis and ANTARES code simulation gives 4.8y (estimated value) Agreement at about 10%

The Pulsar Wind Nebula Vela X R. Coniglione The Pulsar Wind Nebula Vela X

VelaX Gamma spectrum R. Coniglione d=-45.6° Extension: New HESS paper appeared on ArXiv in October 2012 and now on Astronomy and Astrophysics 548 (2012) A38 with a higher flux measurement. (53h 2012/ 12h 2006 of observation) Observation up to 50 TeV d=-45.6° Extension: Inner region 0.8° Total 1.2°

Gamma spectra R. Coniglione N (GeV-1s-1cm-2) G Ecut (TeV) F>1TeV (s-1cm-2) RXJ1713 2.13 10-14 2.04 17.9 1.68 10-11 VelaX 2006* 1.03 10-14 1.45 13.8 1.28 10-11 VelaX 2012 total 1.46 10-14 1.32 14.0 2.10 10-11 VelaX 2012 inner 1.16 10-14 1.36 13.9 1.6 10-11 * F. Aharonian et al., Astronomy & Astrophysics L43 448 (2006)

R. Coniglione Neutrino spectra

Simulation results Years for discovery 5s 50% 3s 50% 7.5 2.6 5.2 1.8 R. Coniglione Simulation results Source at d=-45.6° with a flat disk distribution of 0.8° (inner part of VelaX) Reconstruction with scanning 3°x3° no morphology in simulation no atmospheric muons Official value for public : VelaX about 3 years preliminary Years for discovery 5s 50% 3s 50% Vela X 2006 Kappes 7.5 2.6 VelaX 2006 Vissani 5.2 1.8 VelaX 2012 inner Vissani 2.8 1.1

A. Leisos HOU codes Unbinned search method 3.8 years with HOU codes to be compared with 2.8 years with ANTARES code and binned analysis Difference to be investigated.

The SuperNova Remnant Vela junior R. Coniglione The SuperNova Remnant Vela junior

Vela Junior gamma spectrum SNR Vela Junior d=-46.37° F. Aharonian et al., Astrophys. Journal (2007) 236 data from December 2004 to May 2005 (33h of ON-source run) Observation up to ≈20 TeV no cut off observed Radial profile G=2.24 N=1.9 10-14

Vela Junior gamma spectrum SNR Vela Junior d=-46.37° Manuel Paz Arribas et al., ICRC 2011 Amount of data increased by a factor 2 data from 2004 to 2009 (72h of live time after data quality selection) Morphology analysis -> NO absolute flux values -> *N extracted from 2007 values N (GeV-1s-1cm-2) G Ecut (TeV) F>1TeV (s-1cm-2) VelaJ 2007 *1.89 10-14 2.24 - 1.52 10-11 VelaJ ICRC 2011 single region *1.69 10-14 2.11 VelaJ ICRC 2011 whole *1.86 10-14 2.22

Vela Junior neutrino spectrum * ** N (GeV-1s-1cm-2) G Ecut (TeV) F>1TeV (s-1cm-2) VelaJ Vissani 2007** 6.6 10-15 2.24 - 5.30 10-12 VelaJ Vissani ICRC 2011 single region** 2.64 10-15 2.11 5.71 10-12 VelaJ Kappes* 1.67 10-14 1.72 1.19 4.84 10-12

Simulation results Vela Junior Source at d=-46.37° with a flat disk distribution of 1° Reconstruction with scanning 3°x3° no morphology no atmospheric muons Years for discovery 5s 50% Vela Junior Vissani 2007 >10 VelaJ Vissani ICRC 2011 2.9 + cutoff 13 TeV 6 VelaJ Kappes >>10 No cutoff unrealistic With a supposed cutoff (not measured)

The Fermi bubbles

The Fermi bubble To be confirmed In the paper simulation for 2 x154 towers with multiPMT 180m spaced (≈6km3) Paper appeared in Astroparticle Physics Vol. 42 (feb 2013) 7-14. tower+multipmt detector @180m Discovery for E-2 with a cutoff@100 TeV spectrum in about 1 ÷1 ½ year Discovery for E-2 with a cutoff@30 TeV spectrum in about 5 ÷6 years strings+multipmt detector @100m (no muatm) Discovery for E-2 with a cutoff@100 TeV spectrum in about 1 ÷1 ½ year Discovery for E-2 with a cutoff@30 TeV spectrum in about 3÷4 years To be confirmed

Summary String distance optimization -> 100m No different optimal string distance at different Labs Discovery of RXJ1713 in about 5.8 years (agreement at about 10% with HOU results) Discovery of VelaX in about 3 years (difference with HOU results to be understood)