SLAS Faukles Crab APOD discussion draft by kaf v3.0

Toroidal wisps of a dynamic Crab
Credit & Copyright: Salt Lake Astronomical Society and the Faulkes North Telescope Project, Haleakala, Maui, Hawaii taken Jan. 15, 2010
Click here for feature labeled image

Time and our two-dimensional telescopic view obscures the structure of a dynamic Crab Nebula (Messier 1).  Made using the 2 meter Faulkes North Telescope, this image reveals M1's pulsar and central cavity (false-colored light-blue).  Movement of the pulsar can be heard as it rotates at 30 times a second.  The pulsar's magnetic field generates a synchrotron disk about 1 light-year in diameter.  Gas in the disk moves at 50% of light-speed.  Movement of gas in the synchrotron disk can be seen on a monthly time scale.  The synchrotron disk emits toroidal wisps of gas - seen in the image - that travel at 8% of light-speed.  Movement of the torodial wisps can be seen over an annual time scale.  The pulsar heats and stirs gas in the central cavity, conributing to the 10 light-year diameter nebula expansion at 1160 kms-1.  Movement of central cavity's boundary can be seen over two decades.  Heated gas of the central cavity rises into outer dense nebula layers, cools and then falls back towards the pulsar in tube-like fingers (false-colored pink)   Spectroscopic measurement of these fingers confirms the oblate spherical shape of the Crab in three dimensions.  Most of the Crab's outer dense-gas layer is outside of the image frame. A large filamentary jet protrudes through that layer.

Related links

Jodrell Bank Centre for Astrophysics, Univ. of Manchester. 12-23-2008. The Sounds of Pulsars (audio recording of Crab pulsar). APOD. 3-26-2005. Composite Crab (composite image of puslar and synchrotron). Chandra X-Ray Observatory. 12-28-2009. Crab Nebula Movie Animations (central pulsar over two years). Faulkes Telescope Project. 2009. Crab Nebula animation - pulsar shock blasting out at almost speed of light. News Release. (O. Gomez animation assembled from 2 1/2 years of Faulkes Telescope Project archive images). APOD. 12-27-2001. The Incredible Expanding Crab (animation of two Kitt Peak M1 images taken 24 years apart). Hester, J.J., Stone, J.M, Scowen, P.A. and Jun, B. et al. 1996. WFPC2 Studies of the Crab Nebula. III. Magnetic Rayleigh-Taylor Instabilities and the Origin of the Filaments. Astrophysical J. 456:225-233 at 231 (Fig. 2 illustrates central cavity heating and cooling gas forming Rayleigh-Taylor fingers).

APOD. 10-25-2009. M1: The Crab Nebula from Hubble (detail of the tube-like Rayleigh-Tayler filaments). Space Science Institute. Dec. 1, 2005. Crab Nebula: a Dead Star Creates Celestial Havoc (showing filament jet protruding from outer wall of Crab Nebula at top of image). Fesen, R. A. and Gull, T. R. July 1986. The optical structure of the Crab Nebula's 'jet'.  Astrophysical J. 306(1):259-265 (Figure 1 shows the filamentary jet in relation to the nebula). Cadez, A., Carramiņana, A,.and Vidrih, S. July 2004. Spectroscopy and Three-Dimensional Imaging of the Crab Nebula. Astrophysical J. 609(2):797-809 (Shell is expanding at 1160 kms-1). Vidrih, Simon. 2005. Simon Vidrih Publications List (with link to Crab Nebula 3D movie). APOD. 11-22-1999. VTL-ESO Image of the Crab Nebula (similar image). ESO. 11-17-1999. Centre of the Crab Nebula in Taurus.