› › Radio Polarisation Study Of Th




Diffuse Radio Foregrounds

Author : Matias Vidal Navarro

Publisher : Springer

Page : 231 pages

File Size : 37,83 MB

Release : 2015-12-15

Category : Science

ISBN : 3319262637

Get eBook

Book Description

This extensive thesis work covers several topics, including intensity and polarization, focusing on a new polarization bias reduction method. Vidal studied data from the WMAP satellite, which is low signal-to-noise and as such has to be corrected for polarization bias. He presents a new method for correcting the data, based on knowledge of the underlying angle of polarization. Using this novel method, he sets upper limits for the polarization fraction of regions known to emit significant amounts of spinning dust emissions. He also studies the large-scale loops and filaments that dominate the synchrotron sky. The dominant features are investigated, including identification of several new features. For the North Polar Spur, a model of an expanding shell in the vicinity of the Sun is tested, which appears to fit the data. Implications for CMB polarization surveys are also discussed. In addition, Vidal presents interferometric observations of the dark cloud LDN 1780 at 31 GHz and shows that the spinning dust hypothesis can explain the radio properties observed.



POLARIZATION MEASUREMENTS OF SOLAR TYPE III RADIO BURSTS AT 25.3 MHz

Author : Stanford University. Institute for Plasma Research

Publisher :

Page : 82 pages

File Size : 11,64 MB

Release : 1969

Category :

ISBN :

Get eBook

Book Description

Reported are the results of 1966, 1968, and 1969 polarization measurements of Solar type 3 radio noise bursts made by recording the output of two orthogonally polarized receiving channels and subsequent digital processing of selected data. The processed data yield total intensity, degree of polarization, ellipticity, and polarization ellipse orientation at 1 second intervals. The measurements are made in a 100 Hz bandwidth to minimize the influence of the propagating medium on the measurements. The mean degree of polarization was found to be about 65% in contrast to previous studies which indicated that type 3 events were more weakly polarized. By assuming that type 3 bursts are flare related we study the polarization characteristics of type 3 bursts as a function of the solar longitude of the related flares. The relation between type 3 event polarization characteristics and flare importance is also investigated. The significance of polarization measurements in studies of solar radio events is pointed out and relevant suggestions for further theoretical research are given. (Author).









Cosmic Magnetism,

Author : Percy Seymour

Publisher : CRC Press

Page : 168 pages

File Size : 38,3 MB

Release : 1986

Category : Art

ISBN :

Get eBook

Book Description

The study of extraterrestrial magnetic fields is a relatively new one, confirmation of the existance of the first such field (that of our Sun) having come a s late as 1908. In the past 30 years a great ammount of knowledge has been accumulated on Cosmic Magnetism, which has turned out to be a truly fascinating topic for study. Percy Seymour's book is the first to deal with the topic in a non-mathematical way, and he offers a fine introduction to his subject. The first three chapters consolidate our knowledge on magnetism in general and the magnetic field of the Earth, as well as discussing the reasons for studying astronomy and cosmic magnetism in particular. The remainder of the book is devoted to the main areas of cosmic magnetism - solar, plantetary and interplanetary fields, fields in stars and pulsars, fields of the milky way and fields in other galaxies. Cosmic Magnetism in an ideal book for sixth-formers and undergraduates studying physics or astronomy and will also appeal to amateur astronomers. as previous work on this topic has been 'hidden' in specialised academic journals.