New evidence for strong nonthermal

effects in Tycho’s supernova remnant

Leonid Ksenofontov1

H.J.Völk2, E.G.Berezhko1,

1Yu.G.Shafer Institute of Cosmophysical Research and Aeronomy, Yakutsk, Russia2Max-Planck-Institut für Kernphysik, Heidelberg, Germany

ksenofon@ikfia.ysn.ru

The Multi-Messenger Approach to High Energy Gamma-ray Sources, Barcelona, July 4-7, 2006

The model: supernova explosion

Vp

Vs

shock wave

ejecta (piston)

supernova

CRs

ISM: nH (~1 – 100 cm-3)

T (~104 – 106 K)

B0 (~1 – 100 μG)

SN: ESN (~1051 erg)

Mej (~1 Msun)

Vp0 (~105 km/s)

diffusive shock acceleration

3

f f

f f p Qt p

ww

c g

gg g g a g a c

0,

,

1 ,

t

P Pt

PP P c P

t

w

ww w

w w

3e e

e e e21

1

3

f f pf f p f

t p p p

ww

The model: basic equations

4

2 2 20

4

3

c

c p fP dp

p m c

Hydrodynamicequations

CR transport equationsfor protons and electrons

CR pressure 1 12

( ) ( )4

inj sinj

uQ p p r R

mpInjection term

ρ(r, t) – gas density

w(r, t) – gas velocity

Pg(r, t) – gas pressure

f(p, r, t) – CR distribution function

( ) ( )3

B

pcp p

eBCR diffusion coefficient

2 2

1 2 20

9

4 em c

r B pSynchrotron loss time

Völk et al. 2002, 2005About 10% of the explosion energy has been transferred into CR energy up to now, which means that the CR energy content is Ec = 0.1 Esn.

Distance determinations to Tycho’s supernova:

From the optical measurements d = 2.3 ± 0.8 kpc (Smith et al. 1991)

It is hard to escape from the uncertain range 2 – 4 kpc with the analyses done so far (Ruiz-Lapuente 2004)

What’s new:

From the Chandra measurements Warren et al. (2005) estimate a mean ratio of contact discontinuity (ejecta) radius to blast wave radius as 0.93

Badenes et al. (2005) found that the properties of the X-ray emission are well reproduced by a 1D delayed detonation model with a kinetic energy of ~ 1.2 × 1051 erg.

Qualitative estimate of gamma-ray flux

In the Sedov phase

- constant

3D Simulations by Blondin & Ellison (2001)

Correction factor 1.05

The ratio of the radii of the contact discontinuity and the forward shock

Spectral energy distribution of the gamma-rays

Conclusions:

HEGRA Upper Limit is consistent with the distance 3.3 − 4 kpc The expected π0-decay γ-ray energy flux is (2 − 5)×10−13 erg/(cm2s)

The new Northern hemisphere IACT such as MAGIC, VERITAS will be able to detect Tycho’s SNR

TeV gamma-rays predominantly have hadronic origin

Detection of a TeV signal is also important for the correct determination of key Supernova parameters

Kepler’s SNR

Total (π0-decay + IC) integral γ-ray energy fluxes as a function of γ-ray energy for the same four cases as in Fig.1. For comparison, the respective sensitivities for a 5σ detection in one year with GLAST (Weekes 2003, Proc. 28th ICRC, 8, 3), and in 50 hours at 20º zenith angle for a photon index 2.6 (as for the Crab Nebula) with H.E.S.S. (Funk 2005, in PhD thesis), are shown.