Antimatter from Supernova Remnants

Transcription

1 Antimatter from Supernova Remnants Michael Kachelrieß NTNU, Trondheim with S. Ostapchenko, R. Tomàs

2 - PAMELA anomaly )) )+ φ(e + ) / (φ(e Positron fraction φ(e Muller & Tang 1987 MASS 1989 TS93 HEAT94+95 CAPRICE94 AMS98 HEAT00 Clem & Evenson 2007 PAMELA Energy (GeV) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

3 Astrophysical sources for anti-matter: CR secondaries standard secenario for Galactic CRs: sources are SNRs: kinetic energy output of SNe: 10M ejected with v cm/s every 30 yr L SN,kin erg/s explains local energy density of CR ǫcr 1 ev/cm 3 for a escape time from disc τ esc yr Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

4 Astrophysical sources for anti-matter: CR secondaries standard secenario for Galactic CRs: sources are SNRs: kinetic energy output of SNe: 10M ejected with v cm/s every 30 yr L SN,kin erg/s explains local energy density of CR ǫcr 1 ev/cm 3 for a escape time from disc τ esc yr 1.order Fermi shock acceleration dn/de E γ with γ = diffusion with D(E) τesc (E) E δ and δ 0.5 explains observed spectrum E 2.6 Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

5 Astrophysical sources for anti-matter: CR secondaries standard secenario for Galactic CRs: sources are SNRs: kinetic energy output of SNe: 10M ejected with v cm/s every 30 yr L SN,kin erg/s explains local energy density of CR ǫcr 1 ev/cm 3 for a escape time from disc τ esc yr 1.order Fermi shock acceleration dn/de E γ with γ = diffusion with D(E) τesc (E) E δ and δ 0.5 explains observed spectrum E 2.6 electrons, positrons: τ loss τ esc and τ loss 1/E Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

6 Astrophysical sources for anti-matter: CR secondaries standard secenario for Galactic CRs: sources are SNRs: kinetic energy output of SNe: 10M ejected with v cm/s every 30 yr L SN,kin erg/s explains local energy density of CR ǫcr 1 ev/cm 3 for a escape time from disc τ esc yr 1.order Fermi shock acceleration dn/de E γ with γ = diffusion with D(E) τesc (E) E δ and δ 0.5 explains observed spectrum E 2.6 electrons, positrons: τ loss τ esc and τ loss 1/E electrons dn /de E γ 1 positrons dn + /de E γ δ 1 Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

7 Astrophysical sources for anti-matter: CR secondaries standard secenario for Galactic CRs: sources are SNRs: kinetic energy output of SNe: 10M ejected with v cm/s every 30 yr L SN,kin erg/s explains local energy density of CR ǫcr 1 ev/cm 3 for a escape time from disc τ esc yr 1.order Fermi shock acceleration dn/de E γ with γ = diffusion with D(E) τesc (E) E δ and δ 0.5 explains observed spectrum E 2.6 electrons, positrons: τ loss τ esc and τ loss 1/E electrons dn /de E γ 1 positrons dn + /de E γ δ 1 ratio n + n E δ CR secondaries can not explain increasing positron fraction Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

8 Possible explanations for the PAMELA anomaly: Astrophysics: as primaries from pulsars supernova remnants (SNR) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

9 Possible explanations for the PAMELA anomaly: Astrophysics: as primaries from pulsars supernova remnants (SNR) Dark matter requires large boost factors 100 Sommerfeld enhancement dense, cold clumps Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

10 Possible explanations for the PAMELA anomaly: Astrophysics: as primaries from pulsars supernova remnants (SNR) Dark matter requires large boost factors 100 Sommerfeld enhancement dense, cold clumps exclusive coupling to leptons Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

11 Astrophysical explanations II: SNR [P. Blasi 09 ] N CR (E) N e (E) for energies E m p in acceleration region Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

12 Astrophysical explanations II: SNR [P. Blasi 09 ] N CR (E) N e (E) for energies E m p in acceleration region significant e ± production by CRs even for small τ pp in source Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

13 Astrophysical explanations II: SNR [P. Blasi 09 ] N CR (E) N e (E) for energies E m p in acceleration region significant e ± production by CRs even for small τ pp in source secondary e ± are accelerated, spectra becomes harder Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

14 Astrophysical explanations II: SNR [P. Blasi 09 ] N CR (E) N e (E) for energies E m p in acceleration region significant e ± production by CRs even for small τ pp in source secondary e ± are accelerated, spectra becomes harder several important implications for CR physics: increase of p/p, B/C,... Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

15 Positron ratio from SNR: [Blasi 09 ] Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

16 Antiproton ratio from SNR: [Blasi, Serpico 09 ] Bohm-like ISM ISM+B term Total p - /p e-05 B term A term Kinetic Energy, T [GeV] Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

17 Antiproton ratio from SNR: Supernova remnants Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

18 Antiproton ratio from SNR: [Blasi, Serpico 09 ] where J p,snrs (E) J p (E) 2 n 1 c [A(E) + B(E)] and ( ) 1 E A(E) = γ ξ + r2 dω ω γ 3D Emax 1(ω) m u 2 de E 2 γ σ p p (E, ω), 1 ω B(E) = τ SNR r Emax 2 E 2 γ de E 2 γ σ p p (E, E). E Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

19 Antiproton ratio from SNR: [Blasi, Serpico 09 ] where J p,snrs (E) J p (E) 2 n 1 c [A(E) + B(E)] and ( ) 1 E A(E) = γ ξ + r2 dω ω γ 3D Emax 1(ω) m u 2 de E 2 γ σ p p (E, ω), 1 ω B(E) = τ SNR r Emax 2 E 2 γ de E 2 γ σ p p (E, E). E A increases for large D and small u old SNR Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

20 Antiproton ratio from SNR: [Blasi, Serpico 09 ] where J p,snrs (E) J p (E) 2 n 1 c [A(E) + B(E)] and ( ) 1 E A(E) = γ ξ + r2 dω ω γ 3D Emax 1(ω) m u 2 de E 2 γ σ p p (E, ω), 1 ω B(E) = τ SNR r Emax 2 E 2 γ de E 2 γ σ p p (E, E). E A increases for large D and small u old SNR constraints: t acc D(E)/u 2 < τ SNR and D(E)/u 2 u 1 τ SNR Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

21 Advantage of a Monte Carlo framework: you don t need to think Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

22 Advantage of a Monte Carlo framework: you don t need to think easy to include: time-dependence of v sh, D,... Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

23 Advantage of a Monte Carlo framework: you don t need to think easy to include: time-dependence of v sh, D,... interactions: production of multi-particle states Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

24 Advantage of a Monte Carlo framework: you don t need to think easy to include: time-dependence of v sh, D,... interactions: production of multi-particle states Example: BS and AMS use as average energy fraction per antiproton/positron: ξ e + = Z e + n e + = 0.05, ξ p = Z p n p = 0.17 where Z p 1 σpp inel (E) de E E dσ p p (E, E ) de Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

25 Antiproton energy fraction: QDC simulations give Z e const. and Z p 0.02 const. 0.1 Z p (QGSJET) Z p (SIBYLL) Z p e+11 1e+12 1e+13 1e+14 1e+15 E/eV Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

26 Antiproton energy fraction: QDC simulations give Z e const. and Z p 0.02 const. 0.1 Z p (QGSJET) Z p (SIBYLL) Z p e+11 1e+12 1e+13 1e+14 1e+15 E/eV since multipicity increases fast, ξ e + = Z e +/n e + and ξ p = Z p /n p are strongly energy dependent Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

27 Disadvantage of the stationary framework: shock velocity is time-dependent acceleration efficiency, injection rate,...are time-dependent too Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

28 Disadvantage of the stationary framework: shock velocity is time-dependent acceleration efficiency, injection rate,...are time-dependent too replace parameter X(t) by suitable average X. Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

29 Disadvantage of the stationary framework: shock velocity is time-dependent acceleration efficiency, injection rate,...are time-dependent too replace parameter X(t) by suitable average X. downstream flux is infinite, E max is infinite choose appropriate value Emax > 10 TeV [Blasi, Serpico 09 ] acceleration zone SNR [Ahlers, Mertsch, Sarkar, 09 ] Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

30 Disadvantage of the stationary framework: shock velocity is time-dependent acceleration efficiency, injection rate,...are time-dependent too replace parameter X(t) by suitable average X. downstream flux is infinite, E max is infinite choose appropriate value Emax > 10 TeV [Blasi, Serpico 09 ] acceleration zone SNR [Ahlers, Mertsch, Sarkar, 09 ] large component A requires small v sh and large D, giving small E max protons accelerate efficiently early, produce secondaries in larger acceleration zone in late phase Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

31 Time-dependent framework: [MK, Ostapchenko, Tomas 10 ] spherical SNR shock; v sh (t) from self-similiar solutions Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

32 Time-dependent framework: [MK, Ostapchenko, Tomas 10 ] spherical SNR shock; v sh (t) from self-similiar solutions use random-walk with prescribed diffusion coefficient D Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

33 Time-dependent framework: [MK, Ostapchenko, Tomas 10 ] spherical SNR shock; v sh (t) from self-similiar solutions use random-walk with prescribed diffusion coefficient D E max result of acceleration process Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

34 Time-dependent framework: [MK, Ostapchenko, Tomas 10 ] spherical SNR shock; v sh (t) from self-similiar solutions use random-walk with prescribed diffusion coefficient D E max result of acceleration process QGSJET, JETSET for pp interactions, particle decays Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

35 Time-dependent framework: results for constant D(t) 1 model 1 model 2 E 2 F p 10-1 up down total E (ev) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

36 Time-dependent framework: results for constant D(t) 1 model 1 model 2 E 2 F p 10-1 up down total E (ev) only downstream spectrum, E E max, is stationary upstream is always non-stationary Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

37 Time-dependent framework: results for constant D(t) F - p / F p+p A B A+B E (ev) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

38 Time-dependent framework: results for constant D(t) F - p / F p+p A B A+B E (ev) component A grows as E 2+β = E 1, solely from increase of acceleration zone t acc D(E)/u 2 1 < τ SNR Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

39 Time-dependent framework: results for constant D(t) F - p / F p+p A B A+B E (ev) component A grows as E 2+β = E 1, solely from increase of acceleration zone t acc D(E)/u 2 1 < τ SNR reacceleration is a misnamer Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

40 Time-dependent framework: results for constant D(t) F x - / F x+x e + /(e + +e - ) model 1 model 2 p/(p+p) E (ev) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

41 Time-dependent framework: results with amplification/damping Bell: non-linear coupling between CRs and plasma (Alfven waves) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

42 Time-dependent framework: results with amplification/damping Bell: non-linear coupling between CRs and plasma (Alfven waves) non-linear amplification of B by factor O(100) efficient acceleration of CRs to/beyond the knee in early SNR Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

43 Time-dependent framework: results with amplification/damping Bell: non-linear coupling between CRs and plasma (Alfven waves) non-linear amplification of B by factor O(100) efficient acceleration of CRs to/beyond the knee in early SNR then CR damp Alfven waves, turbulent field homogenous field Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

44 Time-dependent framework: results with amplification/damping Bell: non-linear coupling between CRs and plasma (Alfven waves) non-linear amplification of B by factor O(100) efficient acceleration of CRs to/beyond the knee in early SNR then CR damp Alfven waves, turbulent field homogenous field we model amplification/damping by setting { 1/100 cp D = 20 cp eb, eb, t < t t > t Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

45 Time-dependent framework: results with amplification/damping E 2 F x B F p 10 3 F e A E (ev) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

46 Time-dependent framework: results with amplification/damping F - p / F p+p A B A+B E (ev) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

47 Time-dependent framework: results with amplification/damping F x - / F - x+x e + /(e + +e - ) p/(p+p) E (ev) Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

48 Conclusions Prospects and Conclusions 1 Pulsars are natural solution to Pamela excess 2 Supernova remnants B,BS,AMS: E > 100GeV: p and B/C,... rising KOT: no reacceleration, no rise 3 Origin of difference: partly in interactions use of inconsistent effective parameters in stationary approach 4 test by AMS Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

49 Conclusions Prospects and Conclusions 1 Pulsars are natural solution to Pamela excess 2 Supernova remnants B,BS,AMS: E > 100GeV: p and B/C,... rising KOT: no reacceleration, no rise 3 Origin of difference: partly in interactions use of inconsistent effective parameters in stationary approach 4 test by AMS Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

50 Conclusions Prospects and Conclusions 1 Pulsars are natural solution to Pamela excess 2 Supernova remnants B,BS,AMS: E > 100GeV: p and B/C,... rising KOT: no reacceleration, no rise 3 Origin of difference: partly in interactions use of inconsistent effective parameters in stationary approach 4 test by AMS Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18

51 Conclusions Prospects and Conclusions 1 Pulsars are natural solution to Pamela excess 2 Supernova remnants B,BS,AMS: E > 100GeV: p and B/C,... rising KOT: no reacceleration, no rise 3 Origin of difference: partly in interactions use of inconsistent effective parameters in stationary approach 4 test by AMS Michael Kachelrieß (NTNU Trondheim) Antimatter from Supernova Remnants TeVPA, Paris / 18