UNRAVELING THE GEOMETRY OF THE CRAB NEBULA's 'INNER RING'

Journal Article · Fri Feb 10 00:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/746/1/41· OSTI ID:22011834

Weisskopf, Martin C; Elsner, Ronald F; Kolodziejczak, Jeffery J; O'Dell, Stephen L; Tennant, Allyn F ^[1]

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1. Space Science Office, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

Chandra images of the Crab Nebula resolve the detailed structure of its 'inner ring', possibly a termination shock where pulsar-accelerated relativistic particles begin to emit X radiation. Analysis of these images finds that the center of the ellipse-presumably a circular ring in projection-lies about 0.''9 (10 light days at 2 kpc) from the pulsar's image, at a position angle of about 300 Degree-Sign (east of north). This analysis also measures properties of the ellipse: the position angle of the semi-major axis is about 210 Degree-Sign (east of north); the aspect ratio is 0.49. In a simple-albeit, not unique-de-projection of the observed geometry, a circular ring is centered on the axis of symmetry of the pulsar wind nebula. This ring is not equatorial but rather lies near +4.{sup 0}5 latitude in pulsar-centered coordinates. Alternative geometries are briefly discussed.

• OSTI ID: 22011834
• Journal Information: Astrophysical Journal, Vol. 746, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASPECT RATIO
CRAB NEBULA
PULSARS
RELATIVISTIC RANGE
SYMMETRY