Diapositiva 1

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5th Jetset School on High Performance
Computing in Astrophysics 8th-13th January 2008
Galway, Ireland
Hydrodynamic evolution of ejecta in the Vela SNR
Marco Miceli, INAF Osservatorio Astronomico di
Palermo Consorzio COMETA, Italy
Collaborators F. Bocchino, INAF Osservatorio
Astronomico di Palermo, Italy F. Reale, INAF
OAPa, Università di Palermo, Italy S. Orlando,
INAF Osservatorio Astronomico di Palermo, Italy
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Supernova Remnants

• Supernova explosion
• Total energy released ? 1053 erg
• Visible energy ? 1051 erg
• Mass ejected several solar masses

G292.01.8

• Heating of the ambient medium
• Compression
• Interaction with interstellar clouds

• Formation of blast wave shocks

• Chemical enrichment of the galaxy
• Propagation of supersonic bullets

• Propagation of the ejecta

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The Vela SNR
The Vela SNR
Distance 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
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Hydrodynamic modeling
Aims evolution of supersonic fragments of ejecta
(interaction with the shock waves and with the
ambient medium) Equations of the model
r mass density v bulk velocity P pressure E
tot. energy per unit mass q -k(T) ?T (Spitzer
saturated) n density L(T) radiative losses
function e internal energy per unit mass
P
Numerical solution through the FLASH HD code
(Fryxell, 2000)
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Hydrodynamic modeling

• 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 (R) following Wang Chevalier 2002
• Mshrapnel 1/20 Mej
• rshrapnel c rej

z (cm)
r (cm)
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Hydrodynamic modeling
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.
Pure HD run (no thermal cond. no rad. losses)
executed on the HPC system COMETA (total CPU
time250 h, memory7 Mb, output size3 Gb).
Rshrapnel/R0
Complete run executed on the CINECA CLX cluster
(total CPU time9000 h)
c
Complete runs to be done on the COMETA HPC
system
() Work in progress
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Hydrodynamic modeling
The pure HD run (c 30, Rshr 1/3 R0)
spatial res. 2048 x 2048 point
logr (g/cm3)
T (K)