<i>Elements of Gasdynamics And the Classical Theory of Shock Waves</i>

Zel’dovich, Ya. B.; Raǐzer, Yu. P.; Street, Robert E.

doi:10.1063/1.3022341

Cited by 60 publications

(60 citation statements)

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“…Shock pulsation models (Zeldovich & Raizer 1966) suggest that the shock structure can be subdivided into five principal zones with different physical characteristics: the precursor zone, the shock front, the thermalization zone, the ionization zone, and the zone of the cooling wake which is partially transparent in the Balmer and weak spectral lines. The wake zone, just behind the shock front, is a relatively narrow region in comparison with the photospheric radius (Chadid 2011).…”

Section: Emission Lines and Shock Wavesmentioning

confidence: 99%

Spectroscopic Comparison of Metal-rich RRab Stars of the Galactic Field with their Metal-poor Counterparts

Chadid

Sneden

Preston

2017

ApJ

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We investigate atmospheric properties of 35 stable RRab stars that possess the full ranges of period, light amplitude, and metal abundance found in Galactic RR Lyrae stars. Our results are derived from several thousand echelle spectra obtained over several years with the du Pont telescope of Las Campanas Observatory. Radial velocities of metal lines and the Hα line were used to construct curves of radial velocity versus pulsation phase. From these we estimated radial velocity amplitudes for metal lines (formed near the photosphere) and Hα Doppler cores (formed at small optical depths). We also measured Hα emission fluxes when they appear during primary light rises. Spectra shifted to rest wavelengths, binned into small phase intervals, and coadded were used to perform model atmospheric and abundance analyses. The derived metallicities and those of some previous spectroscopic surveys were combined to produce a new calibration of the Layden abundance scale. We then divided our RRab sample into metal-rich (disk) and metal-poor (halo) groups at [Fe/H] = −1.0, The atmospheres of RRab families, so defined, differ with respect to (a) peak strength of Hα emission flux, (b) Hα radial velocity amplitude, (c) dynamical gravity, (d) stellar radius variation, (e) secondary acceleration during the photometric bump that precedes minimum light, and (g) duration of Hα line-doubling. We also detected Hα line-doubling during the "bump" in the metal-poor family, but not in the metal-rich one. Though all RRab probably are core helium-burning horizontal branch stars, the metal-rich group appear to be a species sui generis.

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Section: Emission Lines and Shock Wavesmentioning

confidence: 99%

Spectroscopic Comparison of Metal-rich RRab Stars of the Galactic Field with their Metal-poor Counterparts

Chadid

Sneden

Preston

2017

ApJ

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“…If we neglect, for the moment, the energy deposition in cosmic rays, and radiative losses, the Hugoniot relations in the limit of high Mach number shocks state (e.g. Zeldovich & Raizer, 1966;McKee & Hollenbach, 1980):…”

Section: Shock Structure and Electron-ion Tempererature Equilibrationmentioning

confidence: 99%

Shocks and particle acceleration in supernova remnants: observational features

Vink

2004

Advances in Space Research

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The last ten years a number of observational advances have substantially increased our knowledge of shock phenomena in supernova remnants. This progress has mainly been made possible by the recent improvements in X-ray and γ-ray instrumentation. It has become clear that some shell-type supernova remnants, e.g. SN 1006, have X-ray emission dominated by synchrotron radiation, proving that electrons are accelerated up to 100 TeV. This is still an order of magnitude below 3 × 10 15 eV, at which energy the ion cosmic ray spectrum at earth shows a spectral break. So one of the major goals is to prove that supernova remnants are capable of accelerating ions at least up that energy. Here I review the evidence that ions and electrons are accelerated up to energies ∼ 100 TeV in supernova remnants, and, in addition, the recent progress that has been made in understanding the physics of collisionless shock fronts and the magnetic fields inside supernova remnants.

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“…In their numerical scheme, MacLow and McCray employ the approximation by Kompaneets (1960, cf. Zeldovich andRaizer 1968) for the dynamics of a thin shell. This approximation, which should be excellent for the problem at hand, consists of assuming that the interior is isobaric and that the surface moves in the direction of its local normal.…”

Section: Supershell Dynamicsmentioning

confidence: 99%

Supershells

McCray

1988

International Astronomical Union Colloquium

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Repeated supernovae from an OB association will, in a few xlO 7 yr, create a cavity of coronal gas in the interstellar medium, with radius > 100 pc, surrounded by a dense expanding shell of cool interstellar gas. Such a cavity will likely burst through the gas layer of a disk galaxy. Such holes and "supershells" have been observed in optical and H I radio emission maps of the Milky Way and other nearby galaxies. The gas swept up in the supershell is likely to become gravitationally unstable, providing a mechanism for propagating star formation that may be particularly effective in irregular galaxies.

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Elements of Gasdynamics And the Classical Theory of Shock Waves

Cited by 60 publications

References 0 publications

Spectroscopic Comparison of Metal-rich RRab Stars of the Galactic Field with their Metal-poor Counterparts

Spectroscopic Comparison of Metal-rich RRab Stars of the Galactic Field with their Metal-poor Counterparts

Shocks and particle acceleration in supernova remnants: observational features

Supershells

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