scholarly journals Clumping of ejecta and accelerated cosmic rays in the evolution of type Ia SNRs

2013 ◽  
Vol 9 (S296) ◽  
pp. 397-398
Author(s):  
S. Orlando ◽  
F. Bocchino ◽  
M. Miceli ◽  
O. Petruk ◽  
M. L. Pumo
Keyword(s):  
Cosmic Rays ◽  
Supernova Remnant ◽  
Contact Discontinuity ◽  
Back Reaction ◽  
Shock Region ◽  
Model Predictions ◽  
Type Ia ◽  
Forward Shock ◽  
Post Shock ◽  
Mhd Modeling

AbstractWe 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 3D MHD modeling. Our model describes the expansion of a SNR through a magnetized interstellar medium (ISM), 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 (FS) and the contact discontinuity (CD) 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 FS-CD 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.

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

2012 ◽  
Vol 749 (2) ◽  
pp. 156 ◽  
Author(s):  
S. Orlando ◽  
F. Bocchino ◽  
M. Miceli ◽  
O. Petruk ◽  
M. L. Pumo
Keyword(s):  
Cosmic Rays ◽  
Supernova Remnants ◽  
Back Reaction ◽  
Type Ia Supernova ◽  
Type Ia

scholarly journals New optically identified supernova remnants in the Large Magellanic Cloud

2020 ◽  
Vol 500 (2) ◽  
pp. 2336-2358
Author(s):  
Miranda Yew ◽  
Miroslav D Filipović ◽  
Milorad Stupar ◽  
Sean D Points ◽  
Manami Sasaki ◽  
...  
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Narrow Band Imaging ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Main Body ◽  
Found Objects ◽  
Type Ia ◽  
Optical Sample

ABSTRACT We present a new optical sample of three Supernova Remnants (SNRs) and 16 Supernova Remnant (SNR) candidates in the Large Magellanic Cloud (LMC). These objects were originally selected using deep H α, [S ii], and [O iii] narrow-band imaging. Most of the newly found objects are located in less dense regions, near or around the edges of the LMC’s main body. Together with previously suggested MCSNR J0541–6659, we confirm the SNR nature for two additional new objects: MCSNR J0522–6740 and MCSNR J0542–7104. Spectroscopic follow-up observations for 12 of the LMC objects confirm high [S ii]/H α emission-line ratios ranging from 0.5 to 1.1. We consider the candidate J0509–6402 to be a special example of the remnant of a possible type Ia Supernova (SN) which is situated some 2° (∼1.75 kpc) north from the main body of the LMC. We also find that the SNR candidates in our sample are significantly larger in size than the currently known LMC SNRs by a factor of ∼2. This could potentially imply that we are discovering a previously unknown but predicted, older class of large LMC SNRs that are only visible optically. Finally, we suggest that most of these LMC SNRs are residing in a very rarefied environment towards the end of their evolutionary span where they become less visible to radio and X-ray telescopes.

Supernova Remnants: An Introductory Review

2004 ◽  
Vol 218 ◽  
pp. 57-64
Author(s):  
Jacco Vink
Keyword(s):  
Cosmic Rays ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Cosmic Ray ◽  
Recent Advances ◽  
Cosmic Ray Acceleration ◽  
Introductory Review

The two main aspects of supernova remnant research addressed in this review are: I. What is our understanding of the progenitors of the observed remnants, and what have we learned from these remnants about supernova nucleosynthesis? II. Supernova remnants are probably the major source of cosmic rays. What are the recent advances in the observational aspects of cosmic ray acceleration in supernova remnants?

Cosmic rays and the Monogem supernova remnant

2004 ◽  
Vol 22 (1) ◽  
pp. 47-63 ◽  
Author(s):  
A.D. Erlykin ◽  
A.W. Wolfendale
Keyword(s):  
Cosmic Rays ◽  
Supernova Remnant

scholarly journals Balmer-dominated shocks in Tycho’s SNR: omnipresence of CRs

2017 ◽  
Vol 12 (S331) ◽  
pp. 248-253
Author(s):  
Sladjana Knežević ◽  
Ronald Läsker ◽  
Glenn van de Ven ◽  
Joan Font ◽  
John C. Raymond ◽  
...  
Keyword(s):  
Line Width ◽  
Cosmic Ray ◽  
Wide Field ◽  
Hydrogen Atoms ◽  
Narrow Line Width ◽  
Shock Region ◽  
Bayesian Evidence ◽  
Post Shock ◽  
Spurious Result ◽  
First Time

AbstractWe present wide-field, spatially and highly resolved spectroscopic observations of Balmer filaments in the northeastern rim of Tycho’s supernova remnant in order to investigate the signal of cosmic-ray (CR) acceleration. The spectra of Balmer-dominated shocks (BDSs) have characteristic narrow (FWHM ~ 10 km s−1) and broad (FWHM ~ 1000 km s−1) Hα components. CRs affect the Hα-line parameters: heating the cold neutrals in the interstellar medium results in broadening of the narrow Hα-line width beyond 20 km s−1, but also in reduction of the broad Hα-line width due to energy being removed from the protons in the post-shock region. For the first time we show that the width of the narrow Hα line, much larger than 20 km s−1, is not a resolution or geometric effect nor a spurious result of a neglected intermediate (FWHM ~ 100 km s−1) component resulting from hydrogen atoms undergoing charge exchange with warm protons in the broad-neutral precursor. Moreover, we show that a narrow line width ≫ 20 km s−1extends across the entire NE rim, implying CR acceleration is ubiquitous, and making it possible to relate its strength to locally varying shock conditions. Finally, we find several locations along the rim, where spectra are significantly better explained (based on Bayesian evidence) by inclusion of the intermediate component, with a width of 180 km s−1on average.

scholarly journals The failure of stellar feedback, magnetic fields, conduction, and morphological quenching in maintaining red galaxies

2019 ◽  
Vol 487 (3) ◽  
pp. 4393-4408 ◽  
Author(s):  
Kung-Yi Su ◽  
Philip F Hopkins ◽  
Christopher C Hayward ◽  
Xiangcheng Ma ◽  
Claude-André Faucher-Giguère ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Mass Range ◽  
Massive Galaxies ◽  
Cooling Flows ◽  
Stellar Feedback ◽  
Type Ia ◽  
Saturation Effects ◽  
Red Galaxies ◽  
Ia Supernovae

ABSTRACT The quenching ‘maintenance’ and related ‘cooling flow’ problems are important in galaxies from Milky Way mass through clusters. We investigate this in haloes with masses ∼$10^{12}\!-\!10^{14}\, {\rm M}_{\odot }$, using non-cosmological high-resolution hydrodynamic simulations with the FIRE-2 (Feedback In Realistic Environments) stellar feedback model. We specifically focus on physics present without AGN, and show that various proposed ‘non-AGN’ solution mechanisms in the literature, including Type Ia supernovae, shocked AGB winds, other forms of stellar feedback (e.g. cosmic rays), magnetic fields, Spitzer–Braginskii conduction, or ‘morphological quenching’ do not halt or substantially reduce cooling flows nor maintain ‘quenched’ galaxies in this mass range. We show that stellar feedback (including cosmic rays from SNe) alters the balance of cold/warm gas and the rate at which the cooled gas within the galaxy turns into stars, but not the net baryonic inflow. If anything, outflowing metals and dense gas promote additional cooling. Conduction is important only in the most massive haloes, as expected, but even at ∼$10^{14}\, {\rm M}_{\odot }$ reduces inflow only by a factor ∼2 (owing to saturation effects and anisotropic suppression). Changing the morphology of the galaxies only slightly alters their Toomre-Q parameter, and has no effect on cooling (as expected), so has essentially no effect on cooling flows or maintaining quenching. This all supports the idea that additional physics, e.g. AGN feedback, must be important in massive galaxies.

scholarly journals Numerically investigating the morphology of the supernova remnant SN 1006 in the ambient medium with a density discontinuity

2019 ◽  
Vol 491 (2) ◽  
pp. 2460-2464 ◽  
Author(s):  
Jun Fang ◽  
Jingwen Yan ◽  
Lu Wen ◽  
Chunyan Lu ◽  
Huan Yu
Keyword(s):  
Supernova Remnant ◽  
Ambient Medium ◽  
X Rays ◽  
X Ray ◽  
North West ◽  
Density Discontinuity ◽  
North East ◽  
The North ◽  
South West ◽  
Type Ia

ABSTRACT Multiband observations on the Type Ia supernova remnant SN 1006 indicate peculiar properties in its morphologies of emission in the radio, optical, and X-ray bands. In the hard X-rays, the remnant is bilateral with two opposite bright limbs with prominent protrusions. Moreover, a filament has been detected at the radio, optical, and soft X-ray wavelengths. The reason for these peculiar features in the morphologies of the remnant is investigated using 3D HD simulations. With the assumption that the supernova ejecta are evolved in the ambient medium with a density discontinuity, the radius of the remnant’s boundary is smaller in the tenuous medium, and the shell consists of two hemispheres with different radii. Along particular line of sights, protrusions appear on the periphery of the remnants since the emission from the edge of the hemisphere with a larger radius is located outside that from the shell of the small hemisphere. Furthermore, the north-west filament of SN 1006 arises as a result of the intersection of the line of sight and the shocked material near the edges of the two hemispheres. It can be concluded that the protrusions on the north-east and south-west limbs and the north-west filament in the morphologies of SN 1006 can be reproduced as the remnants interacting with the medium with a density discontinuity.

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