X-Ray Spectral Morphologies of
Young Supernova Remnants
John P. Hughes
Rutgers University
 Cara Rakowski, Rutgers
 Parviz Ghavamian, Rutgers
 Jessica Warren, Rutgers
 Pat Slane, CfA
 Dave Burrows, Penn State
 Sangwook Park, Penn State
 John Nousek, Penn State
 Gordon Garmire, Penn State
 Peter Roming, Penn State
 Anne Decourchelle, Saclay
October 10, 2002
COSPAR Houston, TX
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Young Supernova Remnants
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Nucleosynthesis
Explosion Mechanism: neutrino driven convection, jets ?
Progenitor mass, influence on environment
Compact objects, pulsars and pulsar wind nebula (PWN)
Cosmic ray acceleration
Dynamical evolution of SNRs
Physics of high Mach number shocks
October 10, 2002
COSPAR Houston, TX
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Overturning Our View of Cas A
Hughes, Rakowski, Burrows, and Slane 2000,
ApJL, 528, L109.
October 10, 2002
COSPAR Houston, TX
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Oxygen-Rich SNR G292.0+1.8
Park et al 2001, ApJL, 564, L39
October 10, 2002
COSPAR Houston, TX
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Oxygen-Rich SNR G292.0+1.8
Ejecta
Rich in O, Ne, and Mg, some Si
[O]/[Ne] < 1
No Si-rich or Fe-rich ejecta
October 10, 2002
COSPAR Houston, TX
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Oxygen-Rich SNR G292.0+1.8
Normal Composition, CSM
Central bright bar – an axisymmetric
stellar wind (Blondin et al, 1996)
Thin, circumferential filaments enclose
ejecta-dominated material – red/blue
supergiant winbd boundary
October 10, 2002
COSPAR Houston, TX
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Oxygen-Rich SNR G292.0+1.8
Point source
Featureless power-law spectrum, photon
index = 1.7
Surrounded by diffuse X-ray/radio nebula
Off center, implied speed of ~800 km/s
October 10, 2002
COSPAR Houston, TX
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PSR J1124-5916 in G292.0+1.8
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Discovered at Parkes (Camilo et al 2002)
P=0.1353140749 s, dP/dt=7.471E-13
Characteristic age ~ 2900 yrs (SNR age ~ 1600 yrs)
Not detected in coherent FFT of Chandra HRC observation
3.5 sigma detection from Zn2 test at radio parameters
Only ~130 pulsed events in 50 ks
October 10, 2002
COSPAR Houston, TX
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PSR J1124-5916
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Image Analysis: point source and elliptical gaussian (small nebula)
Point source contains ~160 X-ray events
Pulsed fraction high ~80%
Unpulsed point source emission < 1.4E-3 cts/s
LBB< 1033 erg/s
Below standard cooling curve for 2000 yr old PSR
October 10, 2002
COSPAR Houston, TX
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DEM L71: Ejecta and Shock Physics
Chandra/NASA
Rutgers Fabry-Perot/NOAO
Hard
H alpha
X-ray
Soft X-ray
Hughes, Ghavamian, Rakowski, and Slane, ApJL, in prep
October 10, 2002
COSPAR Houston, TX
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Fe-Rich Ejecta
October 10, 2002
COSPAR Houston, TX
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Properties of DEM L71 Ejecta
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Outer rim: lowered abundances, ~0.2 solar (LMC ISM)
Core: enhanced Fe abundance, [Fe]/[O] > 5 times solar (ejecta)
Thick elliptical shell, 32” by 40” across (3.9 pc by 4.8 pc)
Dynamical mass estimate
Wang & Chevalier 2001
r’ ~ 3.0
Mej = 1.1 Mch (n/0.5 cm-3)
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EM mass estimate
EM ~ ne nFe V
MFe < 2 Msun
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Main error: source of electrons
Fe-rich, low mass
October 10, 2002
SN Ia
COSPAR Houston, TX
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DEM L71: Shock Physics
Nonradiative Balmer-dominated shock
Measure post-shock proton temperature
October 10, 2002
X-ray emission from thermal bremsstralung
Measure post-shock electron temperature
COSPAR Houston, TX
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Nonradiative Balmer Shocks
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Nonradiative means that a radiative
(cooling) zone does not form
Low density (partially neutral) gas
High velocity shocks
Narrow component: cold H I overrun by
shock, collisionally excited
Broad component: hot postshock
protons that charge exchange with cold
HI
(Chevalier & Raymond 1978; Chevalier, Kirshner, &
Raymond 1980)
Ghavamian, Rakowski, Hughes, and Williams
2002, ApJ, in prep.
October 10, 2002
Width of broad component yields post
shock proton temperature
COSPAR Houston, TX
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Constraining the Electron Temperature
Fit NEI shock models to 3 spatial
zones to follow evolution of Te
 Study 5 azimuthal regions with
sufficient Chandra statistics and
broad Halpha component
 Available data cannot constrain Te
gradients
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Data do determine mean Te
Suggest partial to compete
temperature equilibration
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Rakowski, Ghavamian, Hughes, & Williams 2002,
ApJ, in prep.
October 10, 2002
COSPAR Houston, TX
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Results on Te/Tp from DEM L71
Shows trend for higher equilibration for lower speed shocks
 X-ray/Halpha results consistent with other purely Halpha ones
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October 10, 2002
COSPAR Houston, TX
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THE END
October 10, 2002
COSPAR Houston, TX
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