Does the Crab Have a Shell?

  title={Does the Crab Have a Shell?},
  author={Dale A. Frail and Namir E. Kassim and Tim J. Cornwell and W. M. Goss},
  journal={The Astrophysical Journal Letters},
  pages={L129 - L132}
We present deep images of a region around the Crab Nebula made with the VLA, utilizing new imaging and deconvolution algorithms in a search for a faint radio shell. The existence of a high-velocity, hydrogen-rich envelope has been predicted to account for the low total mass and kinetic energy of the observed nebula. No radio emission was detected from an extended source outside the Crab Nebula. Our limits on surface brightness are sufficiently low to rule out the existence of a shell around the… 
Observations of the Crab Nebula and Its Pulsar in the Far-Ultraviolet and in the Optical
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Chandra Observations of the X-Ray Halo around the Crab Nebula
Two Chandra observations have been used to search for thermal X-ray emission from within and around the Crab Nebula. Dead time was minimized by excluding the brightest part of the nebula from the
Constraints on fast ejecta in the Crab supernova remnant from optical spectral lines
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Search for thermal X-ray features from the Crab nebula with the Hitomi soft X-ray spectrometer
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The Crab Nebula, henceforth the Crab, the remnant of the historical super- nova of 1054 AD, has long been of intense interest. The pulsar at the center of the Crab has a spin-down luminosity ∼10 5
The Crab nebula and the class of Type IIn-P supernovae caused by sub-energetic electron-capture explosions
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The Crab Nebula's dynamical age as measured from its northern filamentary jet
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A Radio Survey for Pulsar Wind Nebulae
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Limits on a radio shell around the Crab Nebula
It has been suggested1 that the supernova of AD1054, which produced the Crab Nebula, was of Type II and resulted from the explosion of a massive (10–15 M\cirċ) star. In this picture, the well
Multifrequency VLA observations of the Crab Nebula at different epochs: expansion and radio spectra of filaments
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G0. 9 + 0. 1 and the emerging class of composite supernova remnants
High-resolution, multifrequency maps of a bright extended radio source near the Galactic center have revealed it to be a classic example of a composite supernova remnant. A steep-spectrum shell of
Halo around the Crab Nebula
It has been argued1 that the supernova of AD 1054 which left the Crab Nebula supernova remnant was of Type II. Such super-novae occur in the spiral arms of galaxies and are believed to have initial
The synchrotron bays of the Crab Nebula - A magnetic structure associated with a presupernova circumstellar disk
We investigate the nature of two large conical indentations in the Crab Nebula's synchrotron emission, commonly known as the east and west 'bays'. Optical images spanning nearly nine decades
Motions and Structure of the Filamentary Envelope of the Crab Nebula
Proper motions have been measured for 132 line-emitting filaments in the Crab Nebula on direct plates taken with the 100 and 200-inch telescopes. These motions, if assumed constant and extrapolated
Formation of the dark bays in the Crab optical synchrotron nebula - Is the Crab pulsar wind bubble interacting with its progenitor's wind?
Models are presented for the formation of the two dark bays in the Crab optical synchrotron nebula, from which the optical synchrotron-emitting particles seem to be excluded. It is proposed that the
The expansion of the Crab Nebula
Using high-resolution radio observations from 1982 and 1987 the expansion of the synchrotron component of the Crab Nebula was measured, including a measurement of the expansion of the nebula's outer
1 Galactic and Extragalactic Radio Astronomy
During 1984 the following programs of research on the interstellar medium and star formation were pursued: 1. In an attempt to determine the interaction between the Sgr A molecular clouds and the
No shell around 3C 58
VLA observations were made in a search for radio emission outside the Crablike remnant 3C 58, where the supernova ejecta might be expected to be interacting with the interstellar medium. No evidence