ROLE OF EJECTA CLUMPING AND BACK-REACTION OF ACCELERATED COSMIC RAYS IN THE EVOLUTION OF TYPE Ia SUPERNOVA REMNANTS

Journal Article · Fri Apr 20 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/749/2/156· OSTI ID:22020393

Orlando, S; Bocchino, F; Miceli, M ^[1]; Petruk, O ^[2]

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1. INAF-Osservatorio Astronomico di Palermo 'G. S. Vaiana', Piazza del Parlamento 1, 90134 Palermo (Italy)
2. Institute for Applied Problems in Mechanics and Mathematics, Naukova Street, 3-b Lviv 79060 (Ukraine)

We investigate the role played by initial clumping of ejecta and by efficient acceleration of cosmic rays (CRs) in determining the density structure of the post-shock region of a Type Ia supernova remnant (SNR) through detailed three-dimensional MHD modeling. Our model describes the expansion of an SNR through a magnetized interstellar medium, including the initial clumping of ejecta and the effects on shock dynamics due to back-reaction of accelerated CRs. The model predictions are compared to the observations of SN 1006. We found that the back-reaction of accelerated CRs alone cannot reproduce the observed separation between the forward shock and the contact discontinuity unless the energy losses through CR acceleration and escape are very large and independent of the obliquity angle. On the contrary, the clumping of ejecta can naturally reproduce the observed small separation and the occurrence of protrusions observed in SN 1006, even without the need of accelerated CRs. We conclude that forward shock-contact discontinuity separation is a probe of the ejecta structure at the time of explosion rather than a probe of the efficiency of CR acceleration in young SNRs.

• OSTI ID: 22020393
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 749; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCELERATION
COMPUTERIZED SIMULATION
COSMIC RADIATION
EXPLOSIONS
MAGNETOHYDRODYNAMICS
SHOCK WAVES
STAR EVOLUTION
SUPERNOVA REMNANTS
SUPERNOVAE
THREE-DIMENSIONAL CALCULATIONS