Polarization Distribution Measurements Research Articles

Comparison of polarization distribution measurement by the LIMM and PWP methods

Two different methods of measurement of polarization distributions in piezoelectric materials, the laser intensity modulation method (LIMM) and the pressure wave propagation (PWP) method, are compared. The two techniques are described, and measurements made on different PVDF-based samples, one with a symmetric and the other one with an antisymmetric structure, are reported. Although the LIMM responds to diffusion of heat and the PWP method to the propagation of a pressure wave, the direct observation of the raw data gives similar information in both cases as far as the symmetry of the polarization distribution is concerned. The specific characteristics of each method are analyzed. >

The Structure of Extended Extragalactic Radio Sources

The observational properties of extragalactic radio sources of sizes comparable with or greater than a typical galactic diameter and intrinsic luminosities at 408 MHz greater than 10 to the 23rd W/Hz are discussed. Following a survey of the major instrumental and observational techniques developed over the last three decades for the measurement of source structure, classes of radio structure that are commonly observed, including narrow edge-brightened and -darkened double sources, narrow- and wide-tailed sources and cluster halos, are described, and various taxonomic sequences of these morphologies are discussed. Means by which such physical properties as the energetics, confinement parameters, magnetic fields, sites of electron acceleration and rotation are derived from intensity and polarization distribution measurements are examined, and the observed characteristics of the various components of extended radio sources are considered in detail, including diffuse emission regions, hot spots, cores and jets. Finally, relationships of radio source morphologies to the properties of the parent galaxies and clusters are reviewed, and a model of the radio-source phenomenon is proposed.

On the Measurement of Polarization Distributions Over Radio Sources.

view Abstract Citations (69) References (4) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Measurement of Polarization Distributions Over Radio Sources. Morris, D. ; Radhakrishnan, V. ; Seielstad, G. A. Abstract `method for the determination of polarization distributions over radio sources by means of internetric techniques is described. An expression is given for the response of an interferometer with rarily polarized antennas, and some special cases of interest are discussed. Publication: The Astrophysical Journal Pub Date: February 1964 DOI: 10.1086/147784 Bibcode: 1964ApJ...139..551M full text sources ADS |