scholarly journals Polarization Tomography with Stokes Parameters

Galaxies ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 92
Author(s):  
Lawrence Rudnick ◽  
Debora Katz ◽  
Lerato Sebokolodi
Keyword(s):  
Stokes Parameter ◽  
Radio Galaxies ◽  
Initial Orientation ◽  
Stokes Parameters ◽  
Powerful Technique ◽  
Cygnus A ◽  
Polarization Tomography ◽  
Polarized Emission ◽  
Hidden Patterns

We present a simple but powerful technique for the analysis of polarized emission from radio galaxies and other objects. It is based on the fact that images of Stokes parameters often contain considerably more information than is available in polarized intensity and angle maps. In general, however, the orientation of the Stokes parameters will not be matched to the position angles of structures in the source. Polarization tomography, the technique presented in this paper, consists of making a series of single linear Stokes parameter images, S(ρ), where each image is rotated by an angle ρ from the initial orientation of Q and U. Examination of these images, in a series of still frames or a movie, reveals often hidden patterns of polarization angles, as well as structures that were obscured by the presence of overlapping polarized emission. We provide both cartoon examples and a quick look at the complex polarized structure in Cygnus A.

Extreme Rotation Measure Radio Galaxies Measuring Cluster Magnetic Fields

1996 ◽  
Vol 175 ◽  
pp. 159-162 ◽  
Author(s):  
C.L. Carilli ◽  
R.A. Perley ◽  
G. Miley ◽  
H. Röttgering ◽  
R. Van OJIK
Keyword(s):  
Magnetic Fields ◽  
Wavelength Dependence ◽  
Radio Galaxies ◽  
Cygnus A ◽  
Rotation Measure ◽  
Polarized Emission

Slysh (1966) first pointed out the bizarre properties of the polarized emission from Cygnus A: a strong wavelength dependence on fractional polarization, and a large difference in rotation measures (RMs) for the (integrated) emission from each lobe. These properties were confirmed, but not resolved, in the work of Mitton (1971) and Alexander et al., (1984).

scholarly journals Modelling of the Magnetic Configuration of CP Stars from Polarimetric Observations

1998 ◽  
Vol 11 (2) ◽  
pp. 679-681
Author(s):  
M. Landolfi
Keyword(s):  
Magnetic Field ◽  
Stokes Parameter ◽  
Quadratic Field ◽  
Mean Field ◽  
Longitudinal Component ◽  
Stokes Parameters ◽  
Longitudinal Field ◽  
The Mean ◽  
The Magnetic Field ◽  
Polarized Radiation

The observational quantities commonly used to study the magnetic field of CP stars – the mean field modulus and the mean longitudinal field, as well as the ‘mean asymmetry of the longitudinal field’ and the ‘mean quadratic field’ recently introduced by Mathys (1995a,b) – are based either on the Stokes parameter / or on the Stokes parameter V. However, a complete description of polarized radiation requires the knowledge of the full Stokes vector: in other words, we should expect that useful information is also contained in linear polarization (the Stokes parameters Q and U); or rather we should expect the information contained in (Q, U) and in V to be complementary, since linear and circular polarization are basically related to the transverse and the longitudinal component of the magnetic field, respectively.

scholarly journals The V-Stokes Parameter as a Manifestation of Envelope Activity for Cool, Bright, Evolved Stars

1988 ◽  
Vol 108 ◽  
pp. 189-190
Author(s):  
B. D. Holenstein ◽  
R. H. Koch ◽  
R. J. Pfeiffer
Keyword(s):  
Radiation Field ◽  
Stokes Parameter ◽  
Stokes Parameters ◽  
Close Binaries ◽  
Evolved Stars

At Pennsylvania’s Flower and Cook Observatory, instrumentation has been developed to measure simultaneously the four Stokes parameters of the filtered radiation field from a celestial source. The instrumental Q/U/V-parameters have been found to be very small and well-behaved. Thus far, the program has concentrated on cool bright giants and supergiants and on hot, evolving close binaries. A single season’s investigation of Alp Ori has already been reported (Holenstein 1987) and the present paper is a summary of current results for the cool, evolved program stars.For Psi1 Aur, V CVn, 6 Gem, 72 Leo and 119 Tau no V-signal at the level of 3σhas been detected from data from the 1986-1987 season. At the level of 0.0n%, unambiguous and variable V-signals have been detected for VV Cep, Mu Cep, Alp Her, Alp Ori, Bet Peg, and Alp Sco.

A Novel Deduction of Stokes Parameters Based on 2-ordered Basis Matrices

2014 ◽  
Vol 556-562 ◽  
pp. 3598-3601
Author(s):  
Jin Zu Ji
Keyword(s):  
Electromagnetic Wave ◽  
Complex Number ◽  
Coordinate Transformation ◽  
Stokes Parameter ◽  
The Other ◽  
Stokes Parameters ◽  
Algebra Structure ◽  
Wave Polarization ◽  
Matrix Operation ◽  
Matrix Problems

Four two-ordered basis matrices were introduced to deduct Stokes parameter representing electromagnetic wave polarization. Two of them have algebra features similar to unity and imaginary of complex number, so an exponential function was defined which can easily express some matrix operation such as coordination rotation in 2-dimension. The other 2 basis matrices were also incorporated to deduce the Stokes parameters. The four matrices have some fatigue algebra structure which was incorporated in deduction. The coordinate transformation was converted to some matrix problems and we get a more concise result.

scholarly journals Observations of Three Radio Galaxies with The Einstein X-Ray Observatory

1980 ◽  
Vol 5 ◽  
pp. 695-697
Author(s):  
E. D. Feigelson ◽  
E. J. Schreier
Keyword(s):  
Radio Galaxies ◽  
X Ray ◽  
Cygnus A ◽  
Early Results ◽  
Radio Lobe ◽  
Extended Radio ◽  
Double Radio Source ◽  
Parent Galaxy ◽  
Detailed Presentation ◽  
Centaurus A

We would like to present early results from the EINSTEIN X-ray Observatory on three radio galaxies: Centaurus A, NGC 315 = DW0055+30, and Cygnus A = 3C405. We hope to demonstrate that imaging X-ray astronomy can provide important insights into the physics and environment of radio galaxies and their extended radio components.NGC 5128, the parent galaxy of the double-double radio source Centaurus A, is the nearest radio galaxy, providing the best testing ground for high resolution X-ray studies. The X-ray morphology has proved to be rich and varied. We detect four distinct components to the X-ray emission: (1) the strong, compact nucleus detected by earlier satellites; (2) extended emission around the nucleus; (3) emission from the inner radio lobes; and (4) a unique X-ray jet between the nucleus and the NE radio lobe. A detailed presentation of these observations can be found in Schreier et al. (1979).

scholarly journals RETRIEVAL OF AEROSOL PHASE FUNCTION AND POLARIZED PHASE FUNCTION FROM POLARIZATION OF SKYLIGHT FOR DIFFERENT OBSERVATION GEOMETRIES

2018 ◽  
Vol XLII-3 ◽  
pp. 857-863
Author(s):  
L. Li ◽  
L. L. Qie ◽  
H. Xu ◽  
Z. Q. Li
Keyword(s):  
Zenith Angle ◽  
Phase Function ◽  
Solar Zenith Angle ◽  
Stokes Parameter ◽  
Principal Plane ◽  
Stokes Parameters ◽  
Retrieval Algorithm ◽  
Optical Parameters ◽  
Skylight Polarization ◽  
Observation Geometry

The phase function and polarized phase function are important optical parameters, which describe scattering properties of atmospheric aerosol particles. Polarization of skylight induced by the scattering processes is sensitive to the scattering properties of aerosols. The Stokes parameters <i>I, Q, U</i> and the polarized radiance <i>L<sub>p</sub></i> of skylight measured by the CIMEL dual-polar sun-sky radiometer CE318- DP can be use to retrieve the phase function and polarized phase function, respectively. Two different observation geometries (i.e., the principal plane and almucantar) are preformed by the CE318-DP to detect skylight polarization. Polarization of skylight depends on the illumination and observation geometries. For the same solar zenith angle, retrievals of the phase function and the polarized phase function are still affected by the observation geometry. The performance of the retrieval algorithm for the principal plane and almucantar observation geometries was assessed by the numerical experiments at two typical high and low sun’s positions (i.e. solar zenith angles are equal to 45&amp;deg; and 65&amp;deg;). Comparing the results for the principal plane and almucantar geometries, it is recommended to utilize the principal plane observations to retrieve the phase function when the solar zenith angle is small. The Stokes parameter <i>U</i> and the polarized radiance <i>L<sub>p</sub></i> from the almucantar observations are suggested to retrieve the polarized phase function, especially for short wavelength channels (e.g., 440 and 500&amp;thinsp;nm).

scholarly journals Polarized Optical and Infrared Emission from High Redshift Radio Galaxies

1994 ◽  
Vol 159 ◽  
pp. 470-470 ◽  
Author(s):  
Buell T. Jannuzi
Keyword(s):  
Active Galactic Nucleus ◽  
Rest Frame ◽  
Near Infrared ◽  
Uv Light ◽  
High Redshift ◽  
Radio Galaxies ◽  
Infrared Emission ◽  
Significant Component ◽  
Extended Radio ◽  
Polarized Emission

We have detected highly polarized (> 5%) optical and/or infrared emission (rest frame UV to near infrared) from 5 of the 8 high redshift radio galaxies (HZRG; z > 0.7) we have observed. There are now a total of 9 (out of 12 observed) HZRG known to be polarized in spatially integrated measurements (cf.). We have made images of the extended polarized emission from two radio galaxies (3C 265 and 3C 256). Detection of extended polarized emission from a HZRG has previously been reported for 3C 368. All of the existing polarization observations support the hypothesis that the “alignment effect” (the tendency of the extended UV light to be aligned with the extended radio emission, e.g.) is not solely produced by a burst of star formation, but contains a very significant component produced by the scattering of the light from a hidden active galactic nucleus (AGN). Our modeling of the frequency dependence of the polarized flux from 3C 265 suggests that the most probable scatterer is dust.

Polarization-Squeezed Light Formation in Cubic–Nonlinear Medium with Dissipation

1997 ◽  
Vol 06 (04) ◽  
pp. 455-466 ◽  
Author(s):  
A. S. Chirkin ◽  
V. V. Volokhovsky
Keyword(s):  
Radiation Intensity ◽  
Noise Level ◽  
Thermal Noise ◽  
Stokes Parameter ◽  
Stokes Parameters ◽  
Correlation Property ◽  
Third Order ◽  
Interaction Length ◽  
Mean Values ◽  
Squeezed Light

The influence of losses and thermal noise on the polarization-squeezed light formation in a medium with third order nonlinearity has been analysed. A method of analysis based on the delta-correlation property of noise was developed. Mean values and variances of some Stokes parameter of the light was calculated. It was shown that optimal interaction length for effective fluctuation suppression in the Stokes parameters is determined by damping constants, noise level, and radiation intensity.

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