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Stephen C.-Y. Ng HKU. Outline What are pulsar wind nebulae? Physical properties and evolution Why study PWNe? Common TeV sources, particle accelerators.

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Presentation on theme: "Stephen C.-Y. Ng HKU. Outline What are pulsar wind nebulae? Physical properties and evolution Why study PWNe? Common TeV sources, particle accelerators."— Presentation transcript:

1 Stephen C.-Y. Ng HKU

2 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 FAN 4, Jul Stephen Ng

3 Pulsar Winds Where does pulsar rotational energy go? Ė >10 35 erg/s < 10% in radiation (mostly  -rays) > 90% in pulsar winds FAN 4, Jul Stephen Ng Credit: D. Page

4 Pulsar Wind FAN 4, Jul Stephen Ng Credit: CXC/D.Berry

5 Termination Shock FAN 4, Jul Stephen Ng Termination shock c c/3 Free -streaming pulsar wind Ejecta/ISM Credit: P. Slane Shocked pulsar wind Pulsar wind nebulae: broadband synchrotron bubbles (see reviews by Gaensler & Slane 2006; Cheng 2009) Gaensler & Slane (2006)

6 Pulsar Wind Nebula Stephen NgFAN 4, Jul

7 NASA/CXC/ESA/2MASS/NRAO Broadband Emission FAN 4, Jul Stephen Ng

8 Crab Nebula FAN 4, Jul Abdo et al. (2010) Synchrotron IC Fermi LAT

9 Why study PWNe? Relativistic shock physics Cosmic ray acceleration Important TeV sources FAN 4, Jul Stephen Ng Sironi & Spitkovsky (2011)

10 Why study PWNe? Relativistic shock physics Cosmic ray acceleration Important TeV sources FAN 4, Jul Stephen Ng Aguilar et al. (2013) e + excess: dark matter decay? Or pulsars/PWNe?

11 Why study PWNe Relativistic shock physics Cosmic ray acceleration Important TeV sources FAN 4, Jul Stephen Ng 35 TeV PWNe: largest group, ~1/4 identified TeV sources

12 PWN Evolution FAN 4, Jul Stephen Ng van der Swaluw et al. (2003)

13 Free Expansion FAN 4, Jul Stephen Ng van der Swaluw et al. (2003)

14 Axisymmetric Structure FAN 4, Jul Stephen Ng CXC/D.BerryLyubarsky (2002)

15 Torus+Jet Kes 75 Gotthelf+00; Ng+ 08 Lu+02; Temim+10 G Slane+02; 04 3C 58 Weisskopf+00; Hester+02 Crab Pavlov+01; Helfand+01 Vela

16 Torus Modelling CrabVelaB J J / G B J / 3C58 J / N157B B J J / G J / G Stephen Ng Ng & Romani (2004; 2008) FAN 4, Jul

17 Hand of God: FAN 4, Jul Stephen Ng Aharonian et al. (2005) HESS TeV MSH 15–52 / PSR B1509–58 NASA/CXC/SAO/Slane et al. Chandra

18 Hand of God: FAN 4, Jul Stephen Ng MSH 15–52 / PSR B1509–58 NASA/CXC/SAO/Slane et al. Chandra Radio Ng et al. (2013,in prep.)

19 Free Expansion FAN 4, Jul Stephen Ng van der Swaluw et al. (2003)

20 Reverse-Shock Interaction FAN 4, Jul Stephen Ng van der Swaluw et al. (2003)

21 NASA/PSU/Pavlov Vela X Stephen Ng Aharonian et al. (2006) TeV Abdo et al. (2010) Fermi Mattana et al. (2011) NASA/SAO/CXC X-rays

22 G327.1–1.1 FAN 4, Jul Stephen Ng Acero et al. (2012) TeV Temim et al. (2009) Radio + X-ray Ng et al. (2013, in prep.) Radio preliminary No Fermi Detection

23 Bow Shock FAN 4, Jul Stephen Ng van der Swaluw et al. (2003)

24 Bow Shocks Supersonic motion in the ISM  bow shocks Stephen Ng CXC/Weiss ISM ram pressure Pulsar wind pressure FAN 4, Jul

25 The Frying Pan G315.9–0.0 / PSR J1437–5959 ~ 2000 km/s Longest pulsar tail > 20pc FAN 4, Jul Stephen Ng Ng et al. (2012 )

26 PSR J1509–5850 / G319.9–0.7 Ng et al. (2010) FAN 4, Jul Stephen Ng Kargaltsev et al. (2008); Ng et al. (2010) X-ray + Radio Radio

27 Multiwavelength Studies FAN 4, Jul Stephen Ng Crab PWN Abdo et al. (2010) Synchrotron IC

28 Multiwavelength Studies FAN 4, Jul Stephen Ng Abdo et al. (2010) MSH 15 ‒ 52 / PSR B1509 ‒ 58

29 1D Modelling FAN 4, Jul Stephen Ng Gelfand et al. (2009)

30 Time Variability FAN 4, Jul Stephen Ng

31 Crab Nebula: A Standard Candle? Cospar 7/16/2012Stephen Ng Wilson-Hodge et al. (2011)

32 Time Variability FAN 4, Jul Stephen Ng NASA/ASU/Hester

33 Crab PWN FAN 4, Jul NASA/ASU/Hester Stephen Ng

34 Vela Jet FAN 4, Jul Stephen Ng NASA/CXC/PSU/Pavlov et al.

35 Vela Jet FAN 4, Jul Stephen Ng Durant et al. (2013)

36 Ng et al. (2008); Livingstone, Ng et al. (2011) PSR J1846  0258 / Kes 75 FAN 4, Jul Stephen Ng

37 Crab  -ray Flares FAN 4, Jul Stephen Ng

38 Crab Flares FAN 4, Jul Stephen Ng Striani et al. (2013)

39 2013 Mar Flare FAN 4, Jul Stephen Ng Striani et al. (2013); Tavani et al. (2013)

40 Flare Spectrum FAN 4, Jul Stephen Ng Striani et al. (2013)

41 Flare Spectrum FAN 4, Jul Stephen Ng Weisskopf et al. (2013)

42 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 FAN 4, Jul Stephen Ng


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