A Stochastic Theory for the Wavelength Dependence of Linear Polarization of Radio Sources

1968 ◽  
Vol 151 ◽  
pp. 65 ◽  
Author(s):  
Samuel J., Jr. Goldstein
Keyword(s):  
Linear Polarization ◽  
Stochastic Theory ◽  
Wavelength Dependence ◽  
Radio Sources

scholarly journals Observations of the Linear Polarization of Radio Sources at 6 cm Wavelength

1968 ◽  
Vol 21 (4) ◽  
pp. 493 ◽  
Author(s):  
D Morris ◽  
JB Whiteoak
Keyword(s):  
Linear Polarization ◽  
High Frequency ◽  
Wavelength Dependence ◽  
Radio Galaxies ◽  
Short Wave ◽  
Radio Sources ◽  
Polarization Data ◽  
Stellar Objects ◽  
Quasi Stellar Objects

The polarizations of 45 sources have been measured at 6 cm wavelength and have been compared with values obtained at longer wavelengths. The resulting wavelength dependence has been studied in relation to the spectra of the sources. For the quasi. stellar objects in particular, polarization features at short wave� lengths are associated with the young components of the source which radiate at high frequency. However, it is not possible to distinguish between radio galaxies and quasi-stellar objects solely on the basis of polarization data.

scholarly journals Oh Observations in the Directions of Galactic Thermal Sources

1967 ◽  
Vol 20 (4) ◽  
pp. 407 ◽  
Author(s):  
RX McGee ◽  
FF Gardner ◽  
BJ Robinson
Keyword(s):  
Linear Polarization ◽  
The Other ◽  
Radio Sources ◽  
Line Radiation ◽  
Thermal Sources ◽  
Made In

A survey for the hydroxyl line radiation has been made in the directions of 30 radio sources (most of them thermal) with the 210 ft telescope of beamwidth 12'� 2 and the multichannel line receiver of bandwidths 10 and 37 kHz. The line at frequency 1665�401 MHz was observed for all sources and the other three lines at 1612, 1667, and 1720 MHz were observed for 10 of the more important sources. The latter were investigated for circular and linear polarization.

scholarly journals Polarization Measurements of Some Herbig Ae/Be Stars

1990 ◽  
Vol 140 ◽  
pp. 323-324
Author(s):  
S. K. Jain ◽  
H.C. Bhatt ◽  
Ram Sagar
Keyword(s):  
Linear Polarization ◽  
Wavelength Dependence ◽  
Be Stars ◽  
Polarization Measurements

We have measured the linear polarization of 8 bright Herbig Ae/Be stars in UBVRI bands. No unique wavelength dependence of polarization magnitude as well as direction is found in these measurements.

scholarly journals Simultaneous Five Color (UBVRI) Polarimetry of VV Puppis

1987 ◽  
Vol 93 ◽  
pp. 203-203
Author(s):  
V. Piirola ◽  
A. Reiz ◽  
G.V. Coyne
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Wavelength Dependence ◽  
Position Angle ◽  
Orbital Inclination ◽  
V Band ◽  
Highly Active ◽  
Phase Interval ◽  
In The Beginning ◽  
Bright Phase

AbstractObservations of linear and circular polarization in five colour bands during a highly active state of VV Puppis in January 86 are reported. A strong linear polarization pulse with the maximum in the blue, PB ≈ 22%, is observed at the end of the bright phase when the active pole is at the limb and a weaker secondary pulse, PB ≈ 7%, is seen in the beginning of the bright phase, when the active pole reappears. Strong positive circular polarization is also observed in the blue and the ultraviolet, РU ≈ PB ≈ 18%, PV ≈ 10% during the bright phase. The circular polarization reverses the sign in the B and V bands during the faint phase and a negative polarization hump is seen when the active pole crosses the limb. The circular polarization in the V band reaches the value PV ≈ −10% at the hump, after which it remains near PV ≈ −5% during the faint phase. This is probably due to radiation coming from the second, less active pole and accretion thus takes place onto both poles. The wavelength dependences of the positive and negative parts of the circular polarization curve are different and no polarization reversal is seen in the U band. The position angle of the linear polarization is well determined during a large portion of the cycle, especially in the V band, thanks to the activity from both poles. A best fit to the position angle curve, taking into account also the duration of the positive circular polarization phase interval ΔΦ = 0.40 (in the V band), yields the values of orbital inclination i = 78° ± 2° and the colatitude of the active magnetic pole ß = 146° ± 2°. The relatively good fit to the position angle data indicates that the simple dipole model is nearly correct in the case of VV Puppis. Some wavelength dependence is, however, seen in the position angle curves, especially in the I band where the slope Δθ/ΔΦ at the main pulse is considerably smaller than in the other bands. The shape of the position angle curves changes also in the blue and the ultraviolet around the middle of the bright phase. This is probably due to optical thickness effects as the side of the accretion column which is toward the observer changes near this phase.

Very long baseline interferometry polarization studies of quasars and active galactic nuclei

1986 ◽  
Vol 64 (4) ◽  
pp. 434-439 ◽  
Author(s):  
J. F. C. Wardle ◽  
D. H. Roberts
Keyword(s):  
Active Galactic Nuclei ◽  
Linear Polarization ◽  
Very Long Baseline Interferometry ◽  
Galactic Nuclei ◽  
Radio Sources ◽  
Long Baseline ◽  
First Results ◽  
Polarization Studies ◽  
Theoretical Issues

We present some first results of a program to map the distribution of linear polarization in compact radio sources with milliarcsecond resolution. We show first-epoch maps of 3C345 and 0735 + 178 and first- and second-epoch maps of OJ287. In general, the polarization is mainly associated with optically thin (jet) components. In the case of OJ287, polarization maps made 1 year apart are strikingly different. We also discuss some of the theoretical issues raised by these observations.

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