A HYPERSPECTRAL VIEW OF THE CRAB NEBULA

Journal Article · Sat May 15 00:00:00 EDT 2010 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/139/5/2083· OSTI ID:21443106

Charlebois, M; Drissen, L; Bernier, A -P ^[1]; Grandmont, F ^[2]; Binette, L ^[3]

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1. Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1V 0A6 (Canada)
2. ABB Bomem Inc., 585 boulevard Charest est, Suite 300, Quebec, Quebec G1K 9H4 (Canada)
3. Instituto de AstronomIa, UNAM, Ap.70-264, 04510 Mexico, DF (Mexico)

We have obtained spatially resolved spectra of the Crab nebula in the spectral ranges 450-520 nm and 650-680 nm, encompassing the H{beta}, [O III] {lambda}4959, {lambda}5007, H{alpha}, [N II] {lambda}6548, {lambda}6584, and [S II] {lambda}6717, {lambda}6731 emission lines, with the imaging Fourier transform spectrometer SpIOMM at the Observatoire du Mont-Megantic's 1.6 m telescope. We first compare our data with published observations obtained either from a Fabry-Perot interferometer or from a long-slit spectrograph. Using a spectral deconvolution technique similar to the one developed by Cadez et al., we identify and resolve multiple emission lines separated by large Doppler shifts and contained within the rapidly expanding filamentary structure of the Crab. This allows us to measure important line ratios, such as [N II]/H{alpha}, [S II]/H{alpha}, and [S II] {lambda}6717 /[S II] {lambda}6731 of individual filaments, providing a new insight on the SE-NW asymmetry in the Crab. From our analysis of the spatial distribution of the electronic density and of the respective shocked versus photoionized gas components, we deduce that the skin-less NW region must have evolved faster than the rest of the nebula. Assuming a very simple expansion model for the ejecta material, our data provide us with a complete tridimensional view of the Crab.

• OSTI ID: 21443106
• Journal Information: Astronomical Journal (New York, N.Y. Online), Vol. 139, Issue 5; Other Information: DOI: 10.1088/0004-6256/139/5/2083; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASYMMETRY
CRAB NEBULA
DOPPLER EFFECT
EMISSION
EXPANSION
FABRY-PEROT INTERFEROMETER
FOURIER TRANSFORM SPECTROMETERS
PHOTOIONIZATION
RADIAL VELOCITY
SPATIAL DISTRIBUTION
SUPERNOVAE
TELESCOPES
BINARY STARS
COSMIC RADIO SOURCES
DISTRIBUTION
ERUPTIVE VARIABLE STARS
INTERFEROMETERS
IONIZATION
MEASURING INSTRUMENTS
NEBULAE
SPECTROMETERS
STARS
SUPERNOVA REMNANTS
VARIABLE STARS
VELOCITY