A CR-HYDRO-NEI MODEL OF STRUCTURE AND BROADBAND EMISSION FROM TYCHO’S SNRSLANE ET AL.

Zhang Ningxiao

WARREN ET AL. 2005

BACKGROUND

Emission of Tycho from Radio to γ-ray. The γ-ray is mainly accelerated from

hadronic processes.

THE ORIGIN OF Γ-RAY

π0-decay Inverse compton (IC) Nonthermal bremsstrahlung

IMPORTANT THERMAL EMISSION

Thermal emission from material compressed by the FS provides particularly important on particle acceleration in SNRs.

The temperature is reduced in the case of efficient acceleration.

The fitting result can show the compression ratio.

For example, RX J1713.7-3946 eliminates π0- decay for the reason of lack of thermal X-ray emission. Thermal emission of CTB 109 is sufficiently high for π0-decay.

PARAMETERS OF TYCHO

C-O Type Ia supernova (spectrum analysis)

Distance is uncertain (2-5kpc,4kpc,2.5-3kpc):

ejecta velocity; light echo; kinematic methods

X-ray emission (ejecta+synchrontron) Ambient density (0.85-2.1 cm^-3, 0.3

cm^-3): X-ray thermal emission; gamma ray

flux; expansion index

THE CR-HYDRO-NEI MODEL

CR : cosmic ray HYDRO : hydrodynamics NEI : non-equilibrium ionization

Character: 1. non-linear diffusive shock acceleration

(DSA) 2. proton and electron spectra coupled

with amplified magnetic field.

LEE ET AL. 2012

GOOD AND ASSUMPTION

Good: evolving full particle spectrum Spatially-resolved A self consistent model

Assumption: Spherically symmetric Star with a ejecta density distribution (1.4

Msun)

MODELING

Initial parameters: d, n0, B0, E51, DSA efficiency

TESTING

SED

CALCULATION OF MODEL

Synchrotron IC Nonthermal bremsstrahlung * including the secondary electrons

Π0-decay (Kamae et al. 2006)

MODEL B LOWER DENSITY

IC DOMINATE

NE NONTHERMAL + THERMAL ?

NW & W

X-RAY AND RADIO

X-ray shock fit well, but declines more slowly than

observed brightness behind the shock.

Radio fit well with a slow rise to a plateau-like

region behind the shock, but not well. because the radio emitting electrons do not

suffer significant radiative losses. (R-T increase B)

MODEL C

MODEL C (HIGH DENSITY)

WIND CAVITY MODEL

n0 : 0.4 cm ^-3 the density out the cavity is low the ionization can be higher due to wind region Include the 0.4 pc wind shell in the model Stellar wind : 3*10^-6 Msun/year V_wind=10 km/s

Result is similar to Model A (n0, profile) Because the mass is low (0.1 to 2.5)

DISCUSSION

Prefer Model A

Exist of R-T 1. cause the CD larger than the model 2. the spectra fitting

NE(0.92), SI (1.85), S(2.45)

DIFFERENCE WITH PREVIOUS

1.Fit with single self-consistent model constrain the density and distinction of

pion-decay or IC; without need to add additional component.

2.Fit with continue zones.(DSA) and Consider the MFA

3.include non-adiabatic (turbulence, Alfven wave speed)

4.do not include steep spectrum of protons (p_max=50TeV)

RESULT

1. π0-decay in FS is the nature of the γ-ray. IC significant in GeV.

2. Ne/Np=0.003 3. 16% kinetic energy converted to

particles 4. proton max energy of 50 TeV 5. distance is 3.2 kpc