Transcript powerpoint

Nucleosynthesis, Pulsars,
Cosmic Rays, and Shock
Physics: High Energy Studies of
Supernova Remnants with
Chandra and XMM-Newton
John P. Hughes
Rutgers University
January 8, 2003
201st AAS Meeting
1
Crab Nebula SN1054
Time spacing ~6 weeks
Polar jet, torus, inner ring (~0.2 pc)
Highly dynamic
Wisps move at ~0.5c
(Hester et al 2002)
PSR spin energy, relativistic wind
Nature of wisps still debated
January 8, 2003
201st AAS Meeting
2
New Pulsars and CCOs
January 8, 2003
Cas A
CXOU J232327.9+584842
CCO
PKS 1209-51/52
1E 1207.4-5209
424 ms (X-ray)
G106.3+2.7
PSR J2229+6114
51.6 ms (radio)
IC 443
CXOU J061705.3+222127
CCO
G292.0+1.8
PSR J1124-5916
135 ms (radio)
RX J0852.0-4622
CXOU J085201.4-461753
CCO
3C 58
PSR J0205+6449
65.7 ms (X-ray)
G54.1+0.3
PSR J1930+1852
136 ms (radio)
201st AAS Meeting
3
3C 58 and NS Cooling





Crab-like remnant
Associated with SN 1181
65.68 ms PSR (Murray et al.
2002)
Distance 3.2 kpc
Spectrum of central source
(Slane et al. 2002)
– Power law: G = 1.7
– TBB < 1.08 x 106 K for 12
km radius neutron star
January 8, 2003

Below “standard” NS cooling
curve
201st AAS Meeting
4
Nucleosynthesis in CC SNe

Hydrostatic nucleosynthesis
– During hydrostatic evolution of star
– Builds up shells rich in H, He, C, O, and Si
– Amount of C, O, Ne, Mg ejected varies strongly with
progenitor mass

Explosive nucleosynthesis
– Some mechanism drives a shock wave with 1051+ erg
through the Fe-core
– Burning front T’s of ~109 K cause explosive O- and Siburning
– Only affects the central parts of the star – outer
layers retain their pre-SN composition
January 8, 2003
201st AAS Meeting
5
Explosive Nucleosynthesis
Process
T (109 K)
Main Products
Explosive complete Si-burning
5.0
“Fe”, He
Explosive incomplete Si-burning
4.0
Si, S, Fe, Ar, Ca
Explosive O-burning
3.3
Explosive Ne/C-burning
January 8, 2003
1.2
201st AAS Meeting
O, Si, S, Ar, Ca
O, Mg, Si, Ne
6
Typical Mass Fractions
Element
O
Ne
Mg
Si
S
Ar
Ca
Fe
January 8, 2003
Ex Ne
0.72
0.13
0.09
0.02
Ex O
0.45
0.005
0.30
0.20
0.025
0.02
201st AAS Meeting
Ex Si-i
Ex Si-c
0.40
0.25
0.06
0.05
0.20
0.70
7
Overturning Our View of Cas A
Hughes, Rakowski, Burrows, and Slane 2000,
ApJL, 528, L109.
January 8, 2003
201st AAS Meeting
8
Cas A - Doppler Imaging by XMM

Similar velocity structures in
different lines
– SE knots blueshifted
– N knots redshifted
– Tight correlation between Si
and S velocities

Fe
– Note velocity distribution in N
– Extends to more positive
velocities than Si or S
Willingale et al 2002, A&A, 381, 1039
January 8, 2003
201st AAS Meeting
9
Cas A – 3D Ejecta Model
“Plane of the sky”
“Rotated”
Red: Si Ka
Green: S Ka
Blue: Fe Ka
Circle: Main shock
Fe-rich ejecta lies outside Si/S-rich ejecta
January 8, 2003
201st AAS Meeting
10
N63A

Middle-aged SNR
– 34” (8.2 pc) in radius
– 2000-5000 yrs old
– 2nd brightest LMC SNR

“Crescent”-shaped features
– Similar to features in Vela
– Clumps of high speed ejecta
– Not ejecta dominated

Triangular hole
– X-ray absorption
– Approx. 450 solar mass cloud
– On near side

No PSR or PWN
– LX < 4x1034 erg s-1
Warren, Hughes, & Slane, ApJ, in press (20 Jan 2003)
January 8, 2003
201st AAS Meeting
11
DEM L71

Middle-aged SNR
– 36” (8.7 pc) in radius
– 4,000 yrs old



Rims: LMC composition
Core: [Fe]/[O] > 5 times solar
Ejecta mass: 1.5 Msun
SN Ia ejecta
Hughes, Ghavamian, Rakowski, & Slane 2003, ApJ, 582, L95
January 8, 2003
201st AAS Meeting
12
N49B

Middle-aged SNR
– 80” (19 pc) in radius
– 5000-10,000 yrs old

Bright and faint rims
– LMC composition
– ISM density varies by x10

Ejecta
– Revealed by equivalent-width maps
– Mg & Si rich, no strong O or Ne
Park, Hughes, Slane, Burrows, Garmire, & Nousek 2003,
ApJ, in prep.
January 8, 2003
201st AAS Meeting
13
SNR 0103-72.6

Middle-aged SNR
– 87” (25 pc) in radius
– >10,000 yrs old (?)

Circular rim
– SMC composition

Central bright region
– O, Ne, Mg, Si-rich ejecta
– No Fe enhancement
Park, et al 2003, ApJ, in prep.
January 8, 2003
201st AAS Meeting
14
DEM L71: Shock Physics
Nonradiative Balmer-dominated shock
Measure post-shock proton temperature
X-ray emission from thermal bremsstralung
Measure post-shock electron temperature
Ha
X-ray
January 8, 2003
201st AAS Meeting
15
Constraining the Electron Temperature
Fit plasma shock models to 3 spatial
zones to follow evolution of Te
 Study 5 azimuthal regions with
sufficient Chandra statistics and
broad Ha component
 Available data cannot constrain Te
gradients


Data do determine mean Te
Suggest partial to compete
temperature equilibration

Rakowski, Ghavamian, & Hughes 2003, ApJ,
submitted
January 8, 2003
201st AAS Meeting
16
Nonradiative Balmer Shocks





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
2003, ApJ, submitted.
January 8, 2003
Width of broad component yields post
shock proton temperature
201st AAS Meeting
17
Results on Te/Tp from DEM L71
Shows trend: higher equilibration for slower shocks
 X-ray/Ha results consistent with other purely Ha ones

January 8, 2003
201st AAS Meeting
18
Future Directions

X-ray expansion (proper motion)
– Cas A: done
– SN1006, Tycho: this year
– Magellanic Cloud SNRs: in a few
years

Ejecta census in LMC/SMC SNRs
– Probe the “Life Cycle of Matter”

Longer observations of PWN
– Explore range of dynamical
variability

More studies of shock physics
– Explore variety of high Machnumber shocks
January 8, 2003
201st AAS Meeting
19
The End
January 8, 2003
201st AAS Meeting
20