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相关论文: Where has all the polarization gone?

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We present the results of a multi-frequency study of the inversion symmetric radio galaxy NGC326 based on Very Large Array observations at 1.4, 1.6, 4.8, 8.5 and 14.9 GHz. The morphological, spectral and polarization properties of this…

天体物理学 · 物理学 2009-11-07 M. Murgia , P. Parma , H. R. de Ruiter , M. Bondi , R. D. Ekers , R. Fanti , E. B. Fomalont

We present 2-4 GHz observations of polarized radio galaxies towards eight fast radio bursts (FRBs), producing grids of Faraday rotation measure (RM) sources with sky densities of 9-28 polarized sources per square degree. Using a Bayesian…

The spiral galaxy NGC 6946 was observed in total intensity and linear polarization in five radio bands between 3cm and 21cm. At the inner edge of the inner gas spiral arm the ordered magnetic field is only mildly compressed and turns…

天体物理学 · 物理学 2009-11-13 Rainer Beck

We observed three radio relics in galaxy clusters and one radio relic candidate at 4.85 and 8.35 GHz in total emission and linearly polarized emission with the Effelsberg 100-m telescope and one radio relic candidate in X-rays with the…

Synchrotron radiation from active galactic nuclei (AGN) is often highly polarized. We present a search for linear polarization with the Very Large Array (VLA) at 4.8 GHz and 8.4 GHz from the nearest AGN, Sagittarius A*. As a part of this…

天体物理学 · 物理学 2009-10-31 Geoffrey C. Bower , Donald C. Backer , Jun-Hui Zhao , Miller Goss , Heino Falcke

We have analyzed the polarization properties of pulsars at an observing frequency of 4.9 GHz. Together with low frequency data, we are able to trace polarization profiles over more than three octaves into an interesting frequency regime. At…

天体物理学 · 物理学 2007-05-23 A. von Hoensbroech , J. Kijak , A. Krawczyk

We use the integrated polarized radio emission at 1.4 GHz ($\Pi_{\rm 1.4\,GHz}$) from a large sample of AGN (796 sources at redshifts $z<0.7$) to study the large-scale magnetic field properties of radio galaxies in relation to the host…

星系天体物理 · 物理学 2015-06-17 Shane P. O'Sullivan , B. M. Gaensler , M. A. Lara-López , S. van Velzen , J. K. Banfield , J. S. Farnes

The existence of a primordial magnetic field at the last scattering surface may induce a measurable Faraday rotation in the polarization of the cosmic microwave background. We calculate the magnitude of this effect by evolving the radiative…

天体物理学 · 物理学 2009-10-28 Abraham Loeb , Arthur Kosowsky

We present an analysis of the polarization of compact radio sources from six pointings of the Westerbork Synthesis Radio Telescope (WSRT) at 350 MHz with 35% coverage in lambda^2. After correcting for the off-axis instrumental polarization…

宇宙学与河外天体物理 · 物理学 2015-05-27 Damon Farnsworth , Lawrence Rudnick , Shea Brown

We present integrated polarization properties of nearby spiral galaxies at 4.8 GHz, and models for the integrated polarization of spiral galaxy disks as a function of inclination. Spiral galaxies in our sample have observed integrated…

天体物理学 · 物理学 2011-02-11 Jeroen M. Stil , Marita Krause , Rainer Beck , A. Russell Taylor

We analyse the polarized emission at 1.4 GHz in a 3x3 deg^2 area at high Galactic latitude (b ~ -40deg). The region, centred in (RA=5h, Dec=-49deg), was observed with the Australia Telescope Compact Array radio-interferometer, whose 3-30…

天体物理学 · 物理学 2009-11-10 E. Carretti , G. Bernardi , R. J. Sault , S. Cortiglioni , S. Poppi

The polarization properties of extragalactic radio sources at frequencies higher than 20 GHz are still poorly constrained. However, their characterization would provide invaluable information about the physics of the emission processes and…

星系天体物理 · 物理学 2016-11-28 V. Galluzzi , M. Massardi

We have used the Very Large Array aperture synthesis telescope to conduct a radio continuum survey of polar-ring galaxies, at 20cm and 6cm. Forty objects were observed at 20cm with 5" resolution. Twenty (50%) of the program sources were…

天体物理学 · 物理学 2009-11-10 A. L. Cox , L. S. Sparke

Multi-frequency (4.6, 5, 5.5, 8, 8.8, 13, 15, 22 & 43 GHz) polarization observations of 6 "blazars" were obtained on the American Very Long Baseline Array (VLBA) over a 24-hr period on 2 July 2006. Observing at several frequencies,…

天体物理学 · 物理学 2009-11-13 Shane P. O'Sullivan , Denise C. Gabuzda

Radio galaxies harbouring jetted active galactic nuclei are a frequent target of very-long-baseline interferometry (VLBI) because they play an essential role in exploring how jets form and propagate. Hence, only few have not been detected…

Deep observations of 6cm polarized radio continuum emission of 8 Virgo spiral galaxies are presented. All galaxies show strongly asymmetric distributions of polarized intensity with elongated ridges located in the outer galactic disk. Such…

天体物理学 · 物理学 2009-11-13 B. Vollmer , M. Soida , R. Beck , M. Urbanik , K. Chyzy , K. Otmianowska-Mazur , J. Kenney , J. van Gorkom

A sample of 129 unresolved radio sources with ultrahigh linear polarization (>30 per cent) has been selected from the NRAO VLA Sky Survey. Such high average linear polarization is unusual in extragalactic sources. Higher resolution…

星系天体物理 · 物理学 2010-09-21 H. Shi , H. Liang , J. L. Han , R. W. Hunstead

In order to determine whether unified models of active galactic nuclei apply to low-luminosity objects, we have undertaken a spectropolarimetric survey of of LINERs and Seyfert nuclei at the Keck Observatory. The 14 objects observed have a…

天体物理学 · 物理学 2009-10-31 A. J. Barth , A. V. Filippenko , E. C. Moran

Centaurus A (Cen A) is a bright radio source associated with the nearby galaxy NGC 5128 where high-resolution radio observations can probe the jet at scales of less than a light-day. The South Pole Telescope (SPT) and the Atacama Pathfinder…

The recent detection of polarized radiation from Sgr A* requires a non-thermal electron distribution for the emitting plasma. The Faraday rotation measure must be small, placing strong limits on the density and magnetic field strength. We…

天体物理学 · 物理学 2009-10-31 Eric Agol