The evolution of mass loaded supernova remnants

Pittard, J. M.; Arthur, S. J.; Dyson, J. E.; Falle, S. A. E. G.; Hartquist, T. W.; Knight, Montgomery; Pexton, Mark

doi:10.1051/0004-6361:20030157

Cited by 15 publications

(18 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They found that the destruction of the clouds leads to the highest densities in the remnant occurring over the outer half radius (in contrast, when there is no mass loading, a thin dense shell forms at the forward shock). These findings have since been supported by Dyson & Hartquist (), who reported a similar ‘thick shell’ morphology in their similarity solutions, and by the additional numerical simulations presented by Dyson, Arthur & Hartquist () and Pittard et al (). The X‐ray emission in these cases becomes softer and more extended.…”

Section: Discussionsupporting

confidence: 62%

Numerical simulations of shocks encountering clumpy regions

Alūzas¹,

Pittard²,

Hartquist³

et al. 2012

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We present numerical simulations of the adiabatic interaction of a shock with a clumpy region containing many individual clouds. Our work incorporates a sub-grid turbulence model which for the first time makes this investigation feasible. We vary the Mach number of the shock, the density contrast of the clouds, and the ratio of total cloud mass to inter-cloud mass within the clumpy region. Cloud material becomes incorporated into the flow. This "mass-loading" reduces the Mach number of the shock, and leads to the formation of a dense shell. In cases in which the mass-loading is sufficient the flow slows enough that the shock degenerates into a wave. The interaction evolves through up to four stages: initially the shock decelerates; then its speed is nearly constant; next the shock accelerates as it leaves the clumpy region; finally it moves at a constant speed close to its initial speed. Turbulence is generated in the post-shock flow as the shock sweeps through the clumpy region. Clouds exposed to turbulence can be destroyed more rapidly than a similar cloud in an "isolated" environment. The lifetime of a downstream cloud decreases with increasing cloud-to-intercloud mass ratio. We briefly discuss the significance of these results for starburst superwinds and galaxy evolution.Comment: 17 pages, 19 figures, accepted for publication in MNRA

show abstract

Section: Discussionsupporting

confidence: 62%

Numerical simulations of shocks encountering clumpy regions

Alūzas¹,

Pittard²,

Hartquist³

et al. 2012

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…Efficient cosmicray acceleration processes may also act to increase the compression factor (Vink 2012). At times t 1 Myr, SNR expansion is expected to slow down to the ambient sound speed (typically ∼ 10 km s −1 ) and merge with the ISM, although the exact details of this process are not clear (Pittard et al 2003). The expansion velocity measured from optical spectroscopy towards the Gum Nebula is v 10 km s −1 (Srinivasan et al 1987, Sahu & Sahu 1993.…”

Section: Implications Of the Fitted Compression Factormentioning

confidence: 99%

A Radio-Polarization and Rotation Measure Study of the Gum Nebula and Its Environment

Purcell

Gaensler

Sun

et al. 2015

ApJ

View full text Add to dashboard Cite

The Gum Nebula is 36 • -wide shell-like emission nebula at a distance of only ∼ 450 pc. It has been hypothesised to be an old supernova remnant, fossil H II region, wind-blown bubble, or combination of multiple objects. Here we investigate the magneto-ionic properties of the nebula using data from recent surveys: radio-continuum data from the NRAO VLA and S-band Parkes All Sky Surveys, and H α data from the Southern H-Alpha Sky Survey Atlas. We model the upper part of the nebula as a spherical shell of ionised gas expanding into the ambient medium. We perform a maximum-likelihood Markov chain Monte-Carlo fit to the NVSS rotation measure data, using the H α data to constrain average electron density in the shell n e . Assuming a latitudinal background gradient in RM we find n e = 1.3 +0.4 −0.4 cm −3 , angular radius φ outer = 22.7 +0.1 −0.1 degrees, shell thickness dr = 18.5 +1.5 −1.4 pc, ambient magnetic field strength B 0 = 3.9 +4.9 −2.2 µG and warm gas filling factor f = 0.3 +0.3 −0.1 . We constrain the local, small-scale (∼ 260 pc) pitch-angle of the ordered Galactic magnetic field to +7 • ℘ +44 • , which represents a significant deviation from the median field orientation on kiloparsec scales (∼ −7.2 • ). The moderate compression factor X = 6.0 +5.1 −2.5 at the edge of the H α shell implies that the 'old supernova remnant' origin is unlikely. Our results support a model of the nebula as a H II region around a wind-blown bubble. Analysis of depolarisation in 2.3 GHz S-PASS data is consistent with this hypothesis and our best-fitting values agree well with previous studies of interstellar bubbles.

show abstract

“…Mac Low & Klessen 2004;McKee & Ostriker 2007;Hennebelle & Falgarone 2012;Padoan et al 2014), galaxy formation (e.g. Sales et al 2010), and the evolution of supernova remnants (SNRs) Cowie et al 1981;White & Long 1991;Dyson et al 2002;Pittard et al 2003).…”

Section: Introductionmentioning

confidence: 99%

A comparison of shock-cloud and wind-cloud interactions: the longer survival of clouds in winds

Goldsmith

Pittard²

2017

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

The interaction of a hot, high-velocity wind with a cold, dense molecular cloud has often been assumed to resemble the evolution of a cloud embedded in a post-shock flow. However, no direct comparative study of these two processes currently exists in the literature. We present 2D adiabatic hydrodynamical simulations of the interaction of a Mach 10 shock with a cloud of density contrast χ = 10 and compare our results with those of a commensurate wind-cloud simulation. We then investigate the effect of varying the wind velocity, effectively altering the wind Mach number M wind , on the cloud's evolution. We find that there are significant differences between the two processes: 1) the transmitted shock is much flatter in the shock-cloud interaction; 2) a low-pressure region in the wind-cloud case deflects the flow around the edge of the cloud in a different manner to the shock-cloud case; 3) there is far more axial compression of the cloud in the case of the shock. As M wind increases, the normalised rate of mixing is reduced. Clouds in winds with higher M wind also do not experience a transmitted shock through the cloud's rear and are more compressed axially. In contrast with shock-cloud simulations, the cloud mixing time normalised by the cloudcrushing time-scale t cc increases for increasing M wind until it plateaus (at t mix 25 t cc ) at high M wind , thus demonstrating the expected Mach scaling. In addition, clouds in high Mach number winds are able to survive for long durations and are capable of being moved considerable distances.

show abstract

The evolution of mass loaded supernova remnants

Cited by 15 publications

References 26 publications

Numerical simulations of shocks encountering clumpy regions

Numerical simulations of shocks encountering clumpy regions

A Radio-Polarization and Rotation Measure Study of the Gum Nebula and Its Environment

A comparison of shock-cloud and wind-cloud interactions: the longer survival of clouds in winds

Contact Info

Product

Resources

About