pulsar wind nebulae - stanford university
TRANSCRIPT
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Pulsar Wind Nebulae:
A Multiwavelength Perspective
Collaborators:J. D. GelfandT. TemimD. CastroS. M. LaMassaB. M. GaenslerJ. P. HughesS. ParkD. J. HelfandO. C. de JagerA. LemiereS. P. ReynoldsS. FunkY. Uchiyama
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
PWNe and Their SNRs
ISM
Shoc
ked
ISM
Shoc
ked
Ejec
ta
Uns
hock
ed E
ject
a
PWN
Puls
ar W
ind
Forward ShockReverse ShockPWN Shock
PulsarTerminationShock
• Pulsar Wind - sweeps up ejecta; shock decelerates flow, accelerates particles; PWN forms
• Supernova Remnant - sweeps up ISM; reverse shock heats ejecta; ultimately compresses PWN; energy distribution of particles in nebula tracks evolution; instabilities at PWN/ejecta interface may allow particle escape
Gaensler & Slane 2006
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Jet/Torus and Ejecta Structure in PWNe
Crab Nebula (CXO+HST+SST)
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
The Surrounding Ejecta: G54.1+0.3
Temim et al. 2010
• G54.1+0.3 is a young PWN - termination shock and jet-like outflow clearly observed
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
The Surrounding Ejecta: G54.1+0.3
Temim et al. 2010
• G54.1+0.3 is a young PWN - termination shock and jet-like outflow clearly observed
• PWN is surrounded by a shell of IR emission - IRS spectroscopy shows dust continuum w/ lines from rapidly-expanding ejecta
![Page 6: Pulsar Wind Nebulae - Stanford University](https://reader030.vdocuments.net/reader030/viewer/2022032610/6238eec0bb0cc155c96b8638/html5/thumbnails/6.jpg)
New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
The Surrounding Ejecta: G54.1+0.3
Temim et al. 2010
• G54.1+0.3 is a young PWN - termination shock and jet-like outflow clearly observed
• PWN is surrounded by a shell of IR emission - IRS spectroscopy shows dust continuum w/ lines from rapidly-expanding ejecta
12
1
2
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
The Surrounding Ejecta: G54.1+0.3• G54.1+0.3 is a young PWN - termination shock and jet-like outflow clearly observed
• PWN is surrounded by a shell of IR emission - IRS spectroscopy shows dust continuum w/ lines from rapidly-expanding ejecta
• IR emission is from freshly-formed ejecta dust heated by stars - Extended IR clump has enhanced temperature and density; possibly compressed by jet Temim et al. 2010
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Broadband Emission from PWNe
• Spin-down power is injected into the PWN at a time-dependent rate
• Assume power law input spectrum:
- note that studies of Crab and other PWNe suggest that there may be multiple components
€
Q(t) =Q0 (t)(Ee /Eb )−α
Gelfand et al. 2009
synchrotronCMB
inverseCompton
€
˙ E = IΩ ˙ Ω = ˙ E 0 1+tτ
−
n+1n−1
• Get associated synchrotron and IC emission from electron population evolved nebula - joint fitting of synchrotron and IC spectra give B
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Broadband Emission from PWNe
synchrotronCMB
inverseCompton
Gelfand et al. 2009Gelfand et al. 2009
• Spin-down power is injected into the PWN at a time-dependent rate
• Assume power law input spectrum:
- note that studies of Crab and other PWNe suggest that there may be multiple components
€
Q(t) =Q0 (t)(Ee /Eb )−α€
˙ E = IΩ ˙ Ω = ˙ E 0 1+tτ
−
n+1n−1
• Get associated synchrotron and IC emission from electron population evolved nebula - joint fitting of synchrotron and IC spectra give B
![Page 10: Pulsar Wind Nebulae - Stanford University](https://reader030.vdocuments.net/reader030/viewer/2022032610/6238eec0bb0cc155c96b8638/html5/thumbnails/10.jpg)
New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Injection from Relativistic Shocks
Spitkovsky 2008
• PIC simulations of particle acceleration in relativistic shocks show build-up of energetic particles (Spitkovsky 2008)
• Multi-component input spectrum: Maxwellian + power law – and possibly more complex if conditions differ at different acceleration sites
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Broadband Observations of 3C 58• 3C 58 is a bright, young PWN - morphology similar to radio/x-ray; suggests low magnetic field - PWN and torus observed in Spitzer/IRAC
• Low-frequency break suggests possible break in injection spectrum - IR flux for entire nebula falls within the extrapolation of the X-ray spectrum - indicates single break just below IR
• Torus spectrum requires change in slope between IR and X-ray bands - challenges assumptions for single power law for injection spectrum
Slane et al. 2008
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Evolution in an SNR: Vela XLaMassa et al. 2008
• XMM spectrum shows nonthermal and ejecta-rich thermal emission from cocoon - reverse-shock crushed PWN and mixed in ejecta?
• Broadband measurements consistent with synchrotron and I-C emission from PL electron spectrum w/ two breaks, or two populations - density too low for pion-production to provide observed γ-ray flux - magnetic field very low (5 µG)
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Evolution in an SNR: Vela X
• XMM large project to map cocoon and much of remaining nebula underway
LaMassa et al. 2008
Slane et al. – in prep
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
5 arcmin
HESS J1640-465
• Extended source identified in HESS GPS - no known pulsar associated with source - may be associated with SNR G338.3-0.0
• XMM observations (Funk et al. 2007) identify extended X-ray PWN
• Chandra observations (Lemiere et al. 2009) reveal neutron star within extended nebula - Lx ∼1033.1 erg s-1 Ė ~ 1036.7 erg s-1
- X-ray and TeV spectrum well-described by leptonic model with B ∼6 µG and t ∼15 kyr - example of late-phase of PWN evolution: X-ray faint, but γ-ray bright
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465
• Extended source identified in HESS GPS - no known pulsar associated with source - may be associated with SNR G338.3-0.0
• XMM observations (Funk et al. 2007) identify extended X-ray PWN
• Chandra observations (Lemiere et al. 2009) reveal neutron star within extended nebula - Lx ∼1033.1 erg s-1 Ė ~ 1036.7 erg s-1
- X-ray and TeV spectrum well-described by leptonic model with B ∼6 µG and t ∼15 kyr - example of late-phase of PWN evolution: X-ray faint, but γ-ray bright
Lemiere et al. 2009
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465
• Extended source identified in HESS GPS - no known pulsar associated with source - may be associated with SNR G338.3-0.0
• XMM observations (Funk et al. 2007) identify extended X-ray PWN
• Chandra observations (Lemiere et al. 2009) reveal neutron star within extended nebula - Lx ∼1033.1 erg s-1 Ė ~ 1036.7 erg s-1
- X-ray and TeV spectrum well-described by leptonic model with B ∼6 µG and t ∼15 kyr - example of late-phase of PWN evolution: X-ray faint, but γ-ray bright
LAT 1 yrsensitivity
Lemiere et al. 2009
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465
• Extended source identified in HESS GPS - no known pulsar associated with source - may be associated with SNR G338.3-0.0
• XMM observations (Funk et al. 2007) identify extended X-ray PWN
• Chandra observations (Lemiere et al. 2009) reveal neutron star within extended nebula - Lx ∼1033.1 erg s-1 Ė ~ 1036.7 erg s-1
- X-ray and TeV spectrum well-described by leptonic model with B ∼6 µG and t ∼15 kyr - example of late-phase of PWN evolution: X-ray faint, but γ-ray bright
• Fermi LAT reveals emission associated with source
Slane et al. 2010
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465Slane et al. 2010• PWN model with evolved power
law electron spectrum fits X-ray and TeV emission - Fermi emission falls well above model
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465Slane et al. 2010• PWN model with evolved power
law electron spectrum fits X-ray and TeV emission - Fermi emission falls well above model
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465Slane et al. 2010• PWN model with evolved power
law electron spectrum fits X-ray and TeV emission - Fermi emission falls well above model
• Modifying low-energy electron spectrum by adding Maxwellian produces GeV emission through inverse Compton scattering - primary contribution is from IR from dust (similar to Vela X) - mean energy (γ∼105) and fraction in power law (∼4%) consistent w/ particle acceleration models
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
HESS J1640-465Slane et al. 2010• PWN model with evolved power
law electron spectrum fits X-ray and TeV emission - Fermi emission falls well above model
• Modifying low-energy electron spectrum by adding Maxwellian produces GeV emission through inverse Compton scattering - primary contribution is from IR from dust (similar to Vela X) - mean energy (γ∼105) and fraction in power law (∼4%) consistent w/ particle acceleration models
• GeV emission can also be fit w/ pion model - requires n0 > 100 cm-3, too large for G338.3-0.3
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
G327.1-1.1: More (Reverse) Shocking Results
Temim et al. 2009
• G327.1-1.1 is a composite SNR for which radio morphology suggests PWN/RS interaction
• Chandra observations show an offset compact source w/ trail of nonthermal emission extending back to radio PWN - compact source is extended and embedded in bowshock- structure - prong-like structures extend from source, inflating bubble in region cleared out by RS
![Page 23: Pulsar Wind Nebulae - Stanford University](https://reader030.vdocuments.net/reader030/viewer/2022032610/6238eec0bb0cc155c96b8638/html5/thumbnails/23.jpg)
New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
G327.1-1.1: More (Reverse) Shocking Results
Temim et al. 2009
• G327.1-1.1 is a composite SNR for which radio morphology suggests PWN/RS interaction
• Chandra observations show an offset compact source w/ trail of nonthermal emission extending back to radio PWN - compact source is extended and embedded in bowshock- structure - prong-like structures extend from source, inflating bubble in region cleared out by RS
![Page 24: Pulsar Wind Nebulae - Stanford University](https://reader030.vdocuments.net/reader030/viewer/2022032610/6238eec0bb0cc155c96b8638/html5/thumbnails/24.jpg)
New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Probing Composite SNRs With Fermi• G327.1-1.1 is a composite SNR for which radio morphology suggests PWN/RS interaction
• Chandra observations show an offset compact source w/ trail of nonthermal emission extending back to radio PWN - compact source is extended and embedded in bowshock- structure - prong-like structures extend from source, inflating bubble in region cleared out by RS
![Page 25: Pulsar Wind Nebulae - Stanford University](https://reader030.vdocuments.net/reader030/viewer/2022032610/6238eec0bb0cc155c96b8638/html5/thumbnails/25.jpg)
New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Probing Composite SNRs With Fermi
• Good candidate for γ-rays,
And…
• G327.1-1.1 is a composite SNR for which radio morphology suggests PWN/RS interaction
• Chandra observations show an offset compact source w/ trail of nonthermal emission extending back to radio PWN - compact source is extended and embedded in bowshock- structure - prong-like structures extend from source, inflating bubble in region cleared out by RS
![Page 26: Pulsar Wind Nebulae - Stanford University](https://reader030.vdocuments.net/reader030/viewer/2022032610/6238eec0bb0cc155c96b8638/html5/thumbnails/26.jpg)
New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Probing Composite SNRs With Fermi
• Watch for studies of this and other such systems with Fermi
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New York, NY 2010Patrick Slane (CfA) Workshop on High Energy Galactic Physics
Summary• Multiwavelength studies of PWNe reveal: - spin properties of central engines - geometry of systems - spatially-resolved spectra - interaction with supernova ejecta - presence of freshly-formed dust
• These lead to constraints on: - particle acceleration in relativistic shocks - formation of jets - physics of pulsar magnetospheres - nature of progenitor stars - early and late-phase evolution of pulsar winds
• Current advances are being made across the electromagnetic spectrum, as well as in theoretical modeling, and point the way for investigations in virtually every wavelength band.