HKU Fermi Workshop

Neutron Star Environment:from Supernova Remnants

to Pulsar Wind Nebulae

Stephen C.-Y. NgMcGill University

Special thanks to Pat Slane for some materials in this talk

Jun 21, 2010

HKU Fermi Workshop

Outline

SNRs and PWNe are important Galactic Gamma-ray sources

High energy emission of SNRs Cosmic ray acceleration Gamma-ray production

Overview of PWNe PWNe in Gamma-rays

Jun 21, 2010

HKU Fermi Workshop

Supernova Remnants

Jun 21, 2010

Forward shock

Reverse shock

Den

sit

y

Radius

Shock Physics

Jun 21, 2010

Reverse shock

Forwardshock

ISMEjecta Contact

discontinuity

HKU Fermi Workshop

Thermal X-ray emission

Thermal X-ray spectrum temperature (107K) and density

Radius age

Jun 21, 2010

E

R

v

n0

HKU Fermi Workshop

Non-thermal SNRs

Cosmic ray acceleration in strong shocks B-field + relativistic particles = synchrotron 274 known Galactic SNRs, < 10 synchrotron-

dominated– e.g. SN1006, Vela Jr, G347.3−0.5

Non-thermal features in historical SNRs– e.g. Cas A, Tycho

Jun 21, 2010

HKU Fermi Workshop

Allen 2000

thermal

nonthermal

Non-thermal Emission

Jun 21, 2010

Allen 2000

HKU Fermi WorkshopEnergy (keV)

Counts

/keV

Cassam-Chenai et al. 2007

SN 1006

HKU Fermi Workshop

Tycho

Forward Shock(nonthermal electrons)

Warren et al. 2005

Reverse Shock(ejecta – Fe,K)

Jun 21, 2010

HKU Fermi Workshop

Gamma-ray Production

2cme

h

h

2cme

0

Leptonic: Inverse-Compton scattering of electrons by CMB, far IR, or star light

Hadronic: Inelastic scattering of protons by nucleons Neutral Pion decay

See talks by Thomas Tam and Bo Zhang

Jun 21, 2010

HKU Fermi Workshop

HESS

Aharonian et al. 2006

Similar morphology in X-ray and TeV suggests I-C emissionbut spectrum seems to suggest 0 -decay

G347.3-0.5 (RX J1713.7-3946)

Acero et al. 2009

XMM

Jun 21, 2010

Fermi Detection

Jun 21, 2010

NASA/DOE/Fermi LAT Collaboration

Abdo et al. 2009

W51C

Abdo et al. 2010

W44

Pulsar Wind Nebulae

Jun 21, 2010

HKU Fermi Workshop

Where does the pulsar rotational energy go?

E>1035erg/s < 10% in radiation (mostly Gamma-rays) > 90% in pulsar winds

http://www.astroscu.unam.mx/neutrones/NS-Picture/MagSphe/MagSphe.html

Pulsar Wind

Jun 21, 2010

HKU Fermi Workshop

Pulsar Wind

Jun 21, 2010

PWN within SNR

ISM

Sh

ock

ed ISM

Sh

ock

ed E

ject

a

Unsh

ock

ed

Eje

cta

PW

N

Puls

ar

Win

d

Forward Shock

Reverse ShockPWN Shock

PulsarTerminationShock

Gaensler & Slane (2006)

Terminationshock

c c/3

Pulsar wind Ejecta

HKU Fermi Workshop

Bow-shocks

Jun 21, 2010

NASA/CXC/Gaensler et al.

IC 443

NASA/CXC/SAO/NF/SNRAO/VLA /Gaensler et al.

The Mouse

HKU Fermi Workshop

NASA/CXC/Palomar/2MASS/NRAO

Broadband Emission

Jun 21, 2010

Axisymmetric Structure

Jun 21, 2010

HKU Fermi Workshop

Torus+jet

Jun 21, 2010

HKU Fermi Workshop

Time Variability

NASA/ASU/J.Hester et al

Jun 21, 2010

HKU Fermi Workshop

Gamma-ray Emission

synchrotron

Abdo et al. (2010)

Jun 21, 2010

Crab PWN

HKU Fermi Workshop

TeV PWNe

Vela X

LaMassa et al. (2008)Aharonian et al. (2006)

NASA/PSU/G.Pavlov et al.

Jun 21, 2010

HKU Fermi Workshop

Abdo et al. (2010)

Vela X

de Jager et al. (2008)

Jun 21, 2010

HKU Fermi Workshop

G0.9+0.1

LaRosa et al. (2000) Aharonian et al. (2005)

Jun 21, 2010

HKU Fermi Workshop

MSH 15-52 / PSR B1509-58

Aharonian et al. (2005) NASA/CXC/SAO/P.Slane et al.

Jun 21, 2010

HKU Fermi Workshop

Kookaburra Complex

Aharonian et al. (2006)

Jun 21, 2010

HKU Fermi Workshop

Aharonian et al. (2006)

PSR B1823-13

XMMG18.0-0.7

Jun 21, 2010

Gaensler et al. 2003

HKU Fermi Workshop

Summary

SNRs and PWNe are important Galactic Gamma-ray source

Broadband emission from radio to TeV

Hadronic and Leptonic scenarios of Gamma-ray production

Fermi can fill up the gap between X-ray and TeV in the SED

Jun 21, 2010