Role of Ejecta Clumping and Back-reaction of Accelerated Cosmic Rays in the Evolution of Type Ia Supernova Remnants

Marco Miceli, Pumo, Petruk, Bocchino, Orlando, Miceli

Risultato della ricerca: Article

41 Citazioni (Scopus)

Abstract

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.
Lingua originaleEnglish
Numero di pagine12
RivistaTHE ASTROPHYSICAL JOURNAL
Volume749
Stato di pubblicazionePublished - 2012

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supernova remnants
ejecta
cosmic ray
cosmic rays
shock
discontinuity
probe
three-dimensional modeling
probes
obliquity
escape
explosions
explosion
energy dissipation
occurrences
expansion
prediction
predictions
energy

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cita questo

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title = "Role of Ejecta Clumping and Back-reaction of Accelerated Cosmic Rays in the Evolution of Type Ia Supernova Remnants",
abstract = "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.",
keywords = "ISM: supernova remnants, cosmic rays, instabilities, magnetohydrodynamics: MHD, shock waves, supernovae: individual: SN 1006",
author = "Marco Miceli and Pumo and Petruk and Bocchino and Orlando and Miceli",
year = "2012",
language = "English",
volume = "749",
journal = "THE ASTROPHYSICAL JOURNAL",
issn = "0004-637X",

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TY - JOUR

T1 - Role of Ejecta Clumping and Back-reaction of Accelerated Cosmic Rays in the Evolution of Type Ia Supernova Remnants

AU - Miceli, Marco

AU - Pumo, null

AU - Petruk, null

AU - Bocchino, null

AU - Orlando, null

AU - Miceli, null

PY - 2012

Y1 - 2012

N2 - 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.

AB - 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.

KW - ISM: supernova remnants

KW - cosmic rays

KW - instabilities

KW - magnetohydrodynamics: MHD

KW - shock waves

KW - supernovae: individual: SN 1006

UR - http://hdl.handle.net/10447/65118

M3 - Article

VL - 749

JO - THE ASTROPHYSICAL JOURNAL

JF - THE ASTROPHYSICAL JOURNAL

SN - 0004-637X

ER -