Estimation of neutrino spectra from AGNs using measured VHE γ-ray spectra

Transcription

1 Estimation of neutrino spectra from AGNs using measured VHE -ray spectra Garabed HALLADJIAN December 9 th, cr-ν workshop, PARIS 9 December 2008 G. Halladjian 1

2 Presentation plan Hypotheses & Aim Extra-Galactic Background Light (EBL) Definition & characteristics Interaction with VHE -rays Optical depth Definition & Analyses Conversion of -ray energy spectrum to ν energy spectrum ν energy spectra for 1ES ν energy spectra index for different AGNs Questions 9 December 2008 G. Halladjian 2

3 Hypotheses AGN Intergalactic Space Earth 9 December 2008 G. Halladjian 3

4 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) ν e 9 December 2008 G. Halladjian 4

5 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) 2. ν oscillation phenomena ν e ν e ν τ 9 December 2008 G. Halladjian 5

6 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) 2. ν oscillation phenomena 3. -rays absorption while they travel through space ν e ν e ν τ 9 December 2008 G. Halladjian 6

7 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) 2. ν oscillation phenomena 3. -rays absorption while they travel through space ν e ν e ν τ 9 December 2008 G. Halladjian 7

8 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) 2. ν oscillation phenomena 3. -rays absorption while they travel through space ν e ν e ν τ 9 December 2008 G. Halladjian 8

9 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) 2. ν oscillation phenomena 3. -rays absorption while they travel through space ν e ν e ν τ 9 December 2008 G. Halladjian 9

10 Hypotheses 1. -rays & ν emitted by π 0 decay (p-p interaction) 2. ν oscillation phenomena 3. -rays absorption while they travel through space ν e ν e ν τ 9 December 2008 G. Halladjian 10

11 Extra-Galactic Background Light (EBL) EBL is the light emitted from all objects in the Universe during its entire history It forms a diffused sea of photons that permeates intergalactic space 9 December 2008 G. Halladjian 11

12 -ray attenuation by EBL (E) + (ε) e + + e 9 December 2008 G. Halladjian 12

13 EBL (different experiments) 9 December 2008 G. Halladjian 13

14 EBL spectra (Upper & lower limits) On Gamma Ray Burst and Blazar AGN Origins of the Ultra-High Energy Cosmic Rays in Light of First Results from Auger Charles D. Dermer 9 December 2008 G. Halladjian 14

15 EBL spectra 9 December 2008 G. Halladjian 15

16 Optical depth τ The optical depth expresses the quantity of light removed from a beam by scattering or absorption during its path through a medium. If I 0 is the intensity of radiation at the source and I is the observed intensity after a given path, then optical depth τ is defined by the following equation: I = I 0 e τ 9 December 2008 G. Halladjian 16

17 Optical depth τ τ E, z = 0 z d z ' 1 1 dµ ' ' εth d ε [ dl 1 µ d z ' 2 n ε ε ', z ' σ ' E dl dz = R H 1 z { 1 z 2 m z 1 z 2 z [ 1 z 2 r Λ ]} 1/2, ε ', µ ] σ E,ε, µ = 3σ T 16 1 β2 [ 2β β β 4 ln 1 β 1 β ] β= 1 ε th ε ε th E, µ = 2m 2 e E 1 µ ' ε th =ε th E ', µ E ' =E 1 z ' Simultaneous constraints on the spectrum of the extragalactic background light and the intrinsic TeV spectra of Mrk 421, Mrk 501, and H Eli Dwek & Frank Krennrich 9 December 2008 G. Halladjian 17

18 1ES z = Dec = -23 o Vis = December 2008 G. Halladjian 18

19 Optical Depth τ 9 December 2008 G. Halladjian 19

20 Optical Depth τ On Gamma Ray Burst and Blazar AGN Origins of the Ultra-High Energy Cosmic Rays in Light of First Results from Auger Charles D. Dermer 9 December 2008 G. Halladjian 20

21 Optical Depth τ 9 December 2008 G. Halladjian 21

22 Optical Depth τ 9 December 2008 G. Halladjian 22

23 -ray spectra (Hess) 9 December 2008 G. Halladjian 23

24 Conversion from -ray to ν spectra Hypothesis: TeV ray emission is dominated by the decay of π 0 produced in p-p interactions The following parameterization is for galactic sources dn p de p =k p E p 1 TeV dn k E de 1TeV dn ν de ν k ν E ν 1 TeV Γ p Γ exp E p ε p exp E ε Γ ν exp E ν ε ν k ν Γ p Γ ν Γ Γ p 0.1 ε ν ε ε p /40 ε p ε ε ν k Potential Neutrino Signals from Galactic -Ray Sources (Aharonian & al.) 9 December 2008 G. Halladjian 24

25 ν spectrum (Hess) Neutrino spectrum 9 December 2008 G. Halladjian 25

26 -ray & ν spectra 9 December 2008 G. Halladjian 26

27 1ES (-ray) -ray spectra at Earth -ray spectra at source (HESS) -ray spectra at source (example) -ray spectra at source (upper limit) -ray spectra at source (lower limit) F = E TeV 1 cm 2 s 1 1 TeV F = E 1. 5 TeV 1 cm 2 s 1 1 TeV F = E TeV 1 cm 2 s 1 1 TeV F = E TeV 1 cm 2 s 1 1 TeV F = E 1.81 TeV 1 cm 2 s 1 1 TeV 9 December 2008 G. Halladjian 27

28 1ES (ν) -ray spectra at Earth ν spectra at source (HESS) ν spectra at source (example) ν spectra at source (upper limit) ν spectra at source (lower limit) F = E TeV 1 cm 2 s 1 1 TeV F = E 1.5 TeV 1 cm 2 s 1 1 TeV F = E 1.41 TeV 1 cm 2 s 1 1 TeV F = E 0.86 TeV 1 cm 2 s 1 1 TeV F = E TeV 1 cm 2 s 1 1 TeV 9 December 2008 G. Halladjian 28

29 Spectrum index AGN z Dec. Γ Earth Γ min Γ max 1ES o ES o PG (0.35) +11 o ES o H o PKS o PKS o December 2008 G. Halladjian 29

30 Questions EBL correction: Γ < 1.6 is physical? Other models for EBL? Internal absorption model? (is going on the good way for us) Conversion -ray flux to ν flux: Need model of p- may be use model developed for GRB in any case, what X-ray data will be used? Thanks! 9 December 2008 G. Halladjian 30