Status of gravitational lens paper Internal note: Results of the optical properties of sea water in the ANTARES site with the OB system

2 Outline Introduction Data acquisition Monte Carlo and parameter for water model Analysis method and chi2-minimization MC and MC and Data comparison Results Lens plots and status

3 Introduction Take data with flashing optical beacon –Plot the hit arrival time distributions for all OMs Simulate many MC samples with different input values: λ a and λ s Compare hit arrival time distributions from MC samples and data Choose MC with λ a and λ s which describes best data

4 Absorption and scattering length (Kopovolich parametrization) Angular distribution of PARTIC model used in simulation 70 m 50 m

5 Histogram Comparison We compare many histograms one for each OM considered To quantify the agreement between the histograms we calculate the χ 2 Data MC

6 MC samples CALIBOB ( eta ~ s ) Different MC input parameters For example:  a = 35, 40, 45, 50, 55, 60, 65, 70, 75 m 9 values  s = 35, 40, 45, 50, 55, 60, 65, 70, 75 m 9 values 9*9 = 81 MC samples for each data run Each data run has his: – detector geometry – charge calibration (from tables given by C. Donzaud) – background noise (from adjacent run) => similar to run-by-run MCs – each OM has his efficiency (from K40 measurement) => more sophisticated than run-by-run MCs

7 Same data distribution compared with two MC PMT located at floor 13

8 Chi2 Procedure Loop over selected floors/OMs of one line Cut a fixed range of hit arrival time distribution ([-10,190 ns], bin size=25 ns) Merge all the cut histogram ranges in one super-histogram ([Floor 13, Floor 21]) Compare super-histogram from data with MC Repeat for all lines (except OB) χ 2 calculated with Chi2Test function of ROOT –Robust, flexible and well tested

9 MC and Data for Line 2 with small χ 2 Time MC Data

10 Compare MC with MC Absorption vs. scattering Calculate Chi2 for each MC template Numbers give normalized chi2 Finds true MC values Scattering length [m] Absorption length [m]

11 All lines MC with MC Minimum for different lines are at same place

12 Two different MC simulations Aasim vs. Calibob Calibob finds nearly back the optical parameters used in Aasim

13 Data runs We use data runs taken with the 6 LEDs of the TOP group of one OB flashing at the same time RunEventsOB lineOB floorIntensityDate High High High Low High High Low

14 OM selection Some OMs are rejected: –OMs too close to the OB Floor > 13 ARS token ring effect, photoelectron region –OMs too far away Floor < 21 Not enough statistics –OMs whose efficiency ε 1.5 –Backwards looking OMs PMT acceptance uncertainty –OMs very inclined Led emission uncertainty –OMs after visual inspection of their distributions

15 DATA: Absorption vs. scattering for Line 2 and Sum of all lines Calculate Chi2 for each MC template Numbers give normalized chi2 Scattering length [m] Absorption length [m]

16 All lines Run New MC Different lines show similar results Last figure shows sum..over all lines

17 Final results Take from lines the MC with smallest chi2 Seven runs with 11 lines each

18

Gravitational Lensing

20 Internal note Webpage Dropbox (Veronique, Joern)

21 New approach: Concentrate on lensed radio- loud AGNs (PKS1830 and B0218) FSRQ (Flat Spectrum Radio Quasar) Very fare objects (not easy to detect) Use lensing to improve intrinsic Luminosity

22 Intrinsic luminosity vs. Luminosity distance Need error on the magnification => Contact Emilio E. Falco as gravitational lensing expert (Also possible include QSO 0957 in IceCube field of view)