marco miceli, inaf – osservatorio astronomico di palermo consorzio cometa, italy collaborators f....
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Marco Miceli, INAF – Osservatorio Astronomico di PalermoConsorzio COMETA, Italy
Collaborators
F. Bocchino, INAF – Osservatorio Astronomico di Palermo, Italy F. Reale, INAF – OAPa, Università di Palermo, ItalyS. Orlando, INAF – Osservatorio Astronomico di Palermo, Italy
5th Jetset School onHigh Performance Computing
in Astrophysics
8th-13th January 2008 Galway, Ireland
Hydrodynamic evolution of Hydrodynamic evolution of ejecta in the Vela SNRejecta in the Vela SNR
Supernova RemnantsSupernova Remnants
Supernova explosion
Total energy released: 1053 erg
“Visible” energy: 1051 erg
Mass ejected: several solar masses
G292.0+1.8
Formation of blast wave shocks Heating of the ambient medium Compression Interaction with interstellar clouds
Propagation of the ejecta Chemical enrichment of the galaxy Propagation of supersonic “bullets”
The Vela SNRThe Vela SNR
The Vela SNRDistance: ~250 pc
Age: ~11000 yr In middle-aged SNR the bulk of the X-ray emission is commonly associated with shocked ISM, but:
Vela SNR: 6 X-ray emitting “shrapnels”, that are probably associated with ejecta (outside the border of the shell).
Recent discovery of new shrapnels inside the shell (Miceli et al. 2007, ApJ accepted)
0.1-2.3 keV
Rosat All Sky Survey
Hydrodynamic modelingHydrodynamic modeling
: mass densityv: bulk velocityP: pressureE: tot. energy per unit massq: (T) T (Spitzer & saturated)n: density (T): radiative losses function: internal energy per unit mass
Numerical solution through the FLASH HD code (Fryxell, 2000)
P=
Aims: evolution of supersonic fragments of ejecta (interaction with the shock waves and with the ambient medium)
Equations of the model:
Hydrodynamic modelingHydrodynamic modeling
r (cm)z
(cm
)
Initial conditions: exploding sphere of ejecta with a density inhomogeneity(i. e. the shrapnel)
Mej = 12 M⊙
E = 1051 erg
R0 = 4.5 x 1018 cm
Vej(R0) = 6 x 1018 cm/s (v(R) r)
(R) following Wang & Chevalier 2002
Mshrapnel = 1/20 Mej
shrapnel = ej
2-D simulations in cylindrical coordinates (axial symmetry). We follow the evolution of the system for ~ 15000 yr (the Vela age is ~ 11000 yr)
Parameter space exploration(*): We investigate how the evolution of the system depends on the density contrast (between the shrapnel and the surrounding ejecta) and on the initial position of the shrapnel.
Rsh
rap
nel/R
0
“Complete” run executed on the CINECA CLX cluster (total CPU time~9000 h)
“Complete” runs to be done on the COMETA HPC system
Pure HD run (no thermal cond. no rad. losses) executed on the HPC system COMETA (total CPU time~250 h, memory~7 Mb, output size~3 Gb).
Hydrodynamic modelingHydrodynamic modeling
(*) Work in progress…
log (g/cm3) T (K)spatial res. 2048 x 2048 point
The Vela SNR0.1-2.4 keV
ROSAT All SKy Survey(0.1-2.4 keV)
The “pure HD” run: = 30, Rshr = 1/3 R0)
Hydrodynamic modelingHydrodynamic modeling