scholarly journals Discovery of Interstellar Circular Polarization in the Direction of the Crab Nebula

1973 ◽  
Vol 52 ◽  
pp. 169-179
Author(s):  
P. G. Martin ◽  
R. Illing ◽  
J. R. P. Angel
Keyword(s):  
Circular Polarization ◽  
Crab Nebula ◽  
Small Component ◽  
Metallic Particles ◽  
The Crab Nebula

A search in many small regions of the Crab Nebula has resulted in the detection of a small component of circular polarization. The variation of the sign and magnitude with position in the Nebula indicates that the polarization is of interstellar origin. On the basis of the polarity, strength, and colour dependence, it is concluded that the composition of the aligned grains causing this polarization is dielectric. Metallic particles are clearly ruled out.

scholarly journals A sensitive upper limit to the circular polarization of the Crab nebula atλ3 mm

2011 ◽  
Vol 528 ◽  
pp. A11 ◽  
Author(s):  
H. Wiesemeyer ◽  
C. Thum ◽  
D. Morris ◽  
J. Aumont ◽  
C. Rosset
Keyword(s):  
Circular Polarization ◽  
Crab Nebula ◽  
Upper Limit ◽  
The Crab Nebula

Search for Optical Circular Polarization in the Crab Nebula

Nature ◽  
1971 ◽  
Vol 230 (5289) ◽  
pp. 103-103 ◽  
Author(s):  
J. D. LANDSTREET ◽  
J. R. P. ANGEL
Keyword(s):  
Circular Polarization ◽  
Crab Nebula ◽  
The Crab Nebula

Observation of Polarization for the Crab Nebula with PHENEX Polarimeter

2010 ◽  
Vol 8 (ists27) ◽  
pp. Tm_35-Tm_40 ◽  
Author(s):  
Yuji KISHIMOTO ◽  
Shuichi GUNJI ◽  
Yushi ISHIKAWA ◽  
Makoto TAKADA ◽  
Tatehiro MIHARA ◽  
...  
Keyword(s):  
Crab Nebula ◽  
The Crab Nebula

A Model for the Moving “Wisps” in the Crab Nebula

1999 ◽  
Vol 512 (2) ◽  
pp. 755-760 ◽  
Author(s):  
Mitchell C. Begelman
Keyword(s):  
Crab Nebula ◽  
The Crab Nebula

scholarly journals Strong Waves from Pulsars and Morphologies in SNRs

1983 ◽  
Vol 101 ◽  
pp. 499-501
Author(s):  
Gregory Benford ◽  
Attilio Ferrari ◽  
Silvano Massaglia
Keyword(s):  
Large Amplitude ◽  
Crab Nebula ◽  
Surrounding Medium ◽  
Low Frequency ◽  
Optical Emission ◽  
Amplitude Wave ◽  
Surface Magnetic Field ◽  
Plasma Absorption ◽  
The Crab Nebula ◽  
Large Amplitude Wave

Canonical models for pulsars predict the emission of low–frequency waves of large amplitudes, produced by the rotation of a neutron star possessing a strong surface magnetic field. Pacini (1968) proposed this as the basic drain which yields to the pulsar slowing–down rate. The main relevance of the large amplitude wave (LAW) is the energetic link it provides between the pulsar and the surrounding medium. This role has been differently emphasized (Rees and Gunn, 1974; Ferrari, 1974), referring to absorption effects by relativistic particle acceleration and thermal heating, either close to the pulsar magnetosphere or in the nebula. It has been analyzed in the special case of the Crab Nebula, where observations are especially rich (Rees, 1971). As the Crab Nebula displays a cavity around the pulsar of dimension ∼1017cm, the function of the wave in sweeping dense gas away from the circumpulsar region is widely accepted. Absorption probably occurs at the inner edges of the nebula; i.e., where the wave pressure and the nebular pressure come into balance. Ferrari (1974) interpreted the wisps of the Crab Nebula as the region where plasma absorption occurs, damping the large amplitude wave and driving “parametric” plasma turbulence, thus trasferring energy to optical radiation powering the nebula. The mechanism has been extended to interpret the specific features of the “wisps” emission (Benford et al., 1978). Possibly the wave fills the nebula completely, permeating the space outside filaments with electromagnetic energy, continuously accelerating electrons for the extended radio and optical emission (Rees, 1971).

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