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Pulsar Wind Nebulae at High Energies. Stephen C.-Y. Ng HKU. Outline. What are pulsar wind nebulae? Physical properties and evolution Why study PWNe ? Common TeV sources, particle accelerators Multiwavelength observations of PWNe Broadband SED Surprise from Fermi : Crab flaring.
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Pulsar Wind Nebulae at High Energies Stephen C.-Y. Ng HKU
Outline • What are pulsar wind nebulae? • Physical properties and evolution • Why study PWNe? • Common TeV sources, particle accelerators • Multiwavelength observations of PWNe • Broadband SED • Surprise from Fermi: Crab flaring Stephen Ng
Pulsar Winds • Where doespulsar rotational energy go? • Ė >1035erg/s • < 10% in radiation (mostly -rays) • > 90% in pulsar winds Credit: D. Page Stephen Ng
Pulsar Wind Stephen Ng Credit: CXC/D.Berry
Termination Shock Free -streaming pulsar wind Shocked pulsar wind • Pulsar wind nebulae: broadband synchrotron bubbles(see reviews by Gaensler & Slane 2006; Cheng 2009) Ejecta/ISM c c/3 Termination shock Credit: P. Slane Gaensler & Slane (2006) Stephen Ng
Pulsar Wind Nebula Stephen Ng
Broadband Emission NASA/CXC/ESA/2MASS/NRAO Stephen Ng
Crab Nebula Fermi LAT Synchrotron IC Stephen Ng Abdo et al. (2010)
Why study PWNe? • Relativistic shock physics • Cosmic ray acceleration • Important TeV sources Sironi& Spitkovsky (2011) Stephen Ng
Why study PWNe? • Relativistic shock physics • Cosmic ray acceleration • Important TeV sources e+ excess: dark matter decay? Or pulsars/PWNe? Stephen Ng Aguilar et al. (2013)
Why study PWNe • Relativistic shock physics • Cosmic ray acceleration • Important TeV sources 35 TeVPWNe: largest group,~1/4 identified TeV sources Stephen Ng
PWN Evolution van derSwaluw et al. (2003) Stephen Ng
Free Expansion van derSwaluw et al. (2003) Stephen Ng
Axisymmetric Structure Lyubarsky (2002) CXC/D.Berry Stephen Ng
Torus+Jet Crab Kes 75 Vela Weisskopf+00; Hester+02 Gotthelf+00; Ng+ 08 G54.1+0.3 3C 58 Pavlov+01; Helfand+01 Lu+02; Temim+10 Slane+02; 04
Torus Modelling Crab Vela B1706-44 J2221+6114 J1930+1852 / G54.1+0.3 J2021+3651 B0540-69 J0205+6449 / 3C58 J1833+1034 / G21.5-0.9 B1800-21 J1124-5916 / G292.0+1.8 J0537-6910 / N157B Stephen Ng Ng & Romani (2004; 2008)
HESS TeV Hand of God: MSH 15–52/ PSR B1509–58 Chandra Aharonian et al. (2005) Stephen Ng NASA/CXC/SAO/Slane et al.
Hand of God: MSH 15–52/ PSR B1509–58 Radio Chandra Stephen Ng NASA/CXC/SAO/Slane et al. Ng et al. (2013,in prep.)
Free Expansion van derSwaluw et al. (2003) Stephen Ng
Reverse-Shock Interaction van derSwaluw et al. (2003) Stephen Ng
Vela X Fermi Mattana et al. (2011) TeV X-rays Aharonian et al. (2006) Abdo et al. (2010) NASA/SAO/CXC Stephen Ng NASA/PSU/Pavlov
G327.1–1.1 preliminary Radio Radio + X-ray Ng et al. (2013, in prep.) TeV No Fermi Detection Aceroet al. (2012) Temim et al. (2009) Stephen Ng
Bow Shock van derSwaluw et al. (2003) Stephen Ng
Bow Shocks • Supersonic motion in the ISM bow shocks ISM ram pressure Pulsar wind pressure CXC/Weiss Stephen Ng
The Frying Pan • G315.9–0.0 / PSR J1437–5959 • ~ 2000 km/s • Longest pulsar tail > 20pc Stephen Ng Ng et al. (2012 )
PSR J1509–5850 / G319.9–0.7 X-ray + Radio Radio Ng et al. (2010) Kargaltsevet al. (2008); Ng et al. (2010) Stephen Ng
Multiwavelength Studies Crab PWN Synchrotron IC Abdo et al. (2010) Stephen Ng
Multiwavelength Studies MSH 15‒52 / PSR B1509‒58 Stephen Ng Abdo et al. (2010)
1D Modelling Gelfand et al. (2009) Stephen Ng
Time Variability Stephen Ng
Crab Nebula:A Standard Candle? Stephen Ng Wilson-Hodge et al. (2011)
Time Variability Stephen Ng NASA/ASU/Hester
CrabPWN Stephen Ng NASA/ASU/Hester
VelaJet Stephen Ng NASA/CXC/PSU/Pavlov et al.
Vela Jet Durant et al. (2013) Stephen Ng
PSR J18460258 / Kes 75 2000 2006 2009 Stephen Ng Ng et al. (2008); Livingstone, Ng et al. (2011)
Crab -ray Flares Stephen Ng
Crab Flares Stephen Ng Striani et al. (2013)
2013 Mar Flare Striani et al. (2013); Tavani et al. (2013) Stephen Ng
Flare Spectrum Striani et al. (2013) Stephen Ng
Flare Spectrum Stephen Ng Weisskopfet al. (2013)
Summary • What are pulsar wind nebulae? • Physical properties and evolution • Why study PWNe? • Common TeV sources, particle accelerators • Multiwavelength observations of PWNe • Broadband SED • Surprise from Fermi: Crab flaring Stephen Ng