Infrared spectroscopy and imaging of the Crab Nebula

Journal Article · Thu Mar 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168525· OSTI ID:6865768

Graham, J R; Wright, G S; Longmore, A J ^[1]

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1. California Institute of Technology, Pasadena (USA) Joint Astronomy Center, Hilo, HI (USA) Royal Observatory, Edinburgh (Scotland)

Infrared spectrophotometry and a forbidden Fe II 1.644 micron emission-line image of the Crab Nebula are presented. Bright Fe II 1.644 micron emission has been detected in three filaments, with values similar to the emission from the supernova remnants IC 443 and the Cygnus Loop. However, unlike the forbidden Fe II emission from the latter objects, which is shock-excited, the emission-line filaments in the Crab are photoionized by the power-law synchrotron emission, which produces an extended, warm photodissociation region where the forbidden Fe II line is collisionally excited. The forbidden Fe II line image shows structure very similar to H-alpha and other emission lines, confirming that the infrared forbidden Fe II line has its origin in the filamentary gas where the optically emitting species are excited. 66 refs.

• OSTI ID: 6865768
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 352; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BREMSSTRAHLUNG
COSMIC GASES
COSMIC RADIO SOURCES
CRAB NEBULA
DISSOCIATION
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
FLUIDS
GASES
INFRARED RADIATION
IONIZATION
NEBULAE
PHOTOIONIZATION
RADIATIONS
SHOCK WAVES
SPECTRA
SPECTROPHOTOMETRY
SUPERNOVA REMNANTS
SYNCHROTRON RADIATION