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Related papers: The Galactic Centre region

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We present sensitive radio continuum images at high resolution of 37 radio galaxies at z > 2. The observations were made with the Very Large Array (VLA) at 4.7 GHz and 8.2 GHz, with typical resolutions of 0.45'' and 0.25'', respectively.…

We present a large-scale view of the magnetic field in the central 2deg * 2deg region of our Galaxy. The polarization of point sources has been measured in the J, H, and Ks bands using the near-infrared polarimetric camera SIRPOL on the 1.4…

Magnetic fields remain an enigmatic part of the content of galaxy clusters. Faraday rotation and depolarisation of extragalactic radio sources are useful probes, but the limited availability of polarised radio sources necessitates stacking…

At radio wavelengths, images of the compact radio source Sagittarius A* (Sgr A*) in the Galactic Center are scatter broadened with a lambda^2 dependence due to an intervening ionized medium. We present VLBI observations of Sgr A* at 86 GHz…

We present new, multiwavelength Very Large Array observations of the 3 radio galaxies in the cluster Abell 119: 0053-015, 0053-016 and 3C 29. The first two radio galaxies, which lie close to the cluster center, show a narrow-angle-tailed…

Astrophysics · Physics 2007-05-23 L. Feretti , D. Dallacasa , F. Govoni , G. Giovannini , G. B. Taylor , U. Klein

Studying the interaction between AGN jets and lobes and their surrounding environment is important in order to understand how they transfer energy to their environment as well as determining the intrinsic physical properties of the sources…

Astrophysics of Galaxies · Physics 2018-11-08 S. Knuettel , S. P. O'Sullivan , S. Curiel , B. H. C. Emonts

We examine the magnetic field in NGC 4214, a nearby irregular galaxy, using multi-wavelength radio continuum polarization data from the Very Large Array. We find that the global radio continuum spectrum shows signs that free-free absorption…

Astrophysics of Galaxies · Physics 2015-05-28 Amanda Kepley , Ellen Zweibel , Eric Wilcots , Kelsey Johnson , Timothy Robishaw

We report the detection of circular polarization in the compact radio jet of the nearby spiral galaxy M81 (M81*). The observations were made with the Very Large Array at 4.8 and 8.4 GHz and circular polarization was detected at both…

Astrophysics · Physics 2009-11-07 A. Brunthaler , G. C. Bower , H. Falcke , R. R. Mellon

The magnetic structure in the Galactic disk, the Galactic center and the Galactic halo can be delineated more clearly than ever before. In the Galactic disk, the magnetic structure has been revealed by starlight polarization within 2 or 3…

Astrophysics of Galaxies · Physics 2009-11-13 J. L. Han

Observations by the H.E.S.S. system of imaging atmospheric Cherenkov telescopes provide the most sensitive measurements of the Galactic Centre region in the energy range 150 GeV - 30 TeV. The vicinity of the kinetic centre of our galaxy…

Astrophysics · Physics 2008-11-26 C. van Eldik , O. Bolz , I. Braun , G. Hermann , J. Hinton , W. Hofmann

We describe a first attempt to derive properties of the regular and turbulent Galactic magnetic field from multi-frequency polarimetric observations of the diffuse Galactic synchrotron background. A single-cell-size model of the thin…

Astrophysics · Physics 2009-11-10 M. Haverkorn , P. Katgert , A. G. de Bruyn

We present a catalog of Faraday rotation measures (RMs) and redshifts for 4003 extragalactic radio sources detected at 1.4 GHz, derived by identifying optical counterparts and spectroscopic redshifts for linearly polarized radio sources…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-02 Alison M. Hammond , Timothy Robishaw , B. M. Gaensler

The evidence for the presence of a concentration of dark matter at the Galactic center is now very compelling. There is no question that the stellar and gas kinematics within 0.01 pc is dominated by under-luminous matter in the form of…

Astrophysics · Physics 2009-10-30 Fulvio Melia , Robert Coker

We study the properties of magnetic fields in the circumgalactic medium (CGM) of $z<1$ galaxies by correlating Faraday rotation measures of $\sim 1,000$ high-redshift radio sources with the foreground galaxy number density estimated from…

Astrophysics of Galaxies · Physics 2020-06-24 Ting-Wen Lan , J. Xavier Prochaska

Multifrequency polarimetric observations made with the Very Long Baseline Array of the quasar 3C216 reveal the presence of Faraday rotation measures (RMs) in excess of 2000 rad/m**2 in the source rest frame, in the arc of emission located…

Astrophysics · Physics 2009-10-31 T. Venturi , G. B. 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…

Astrophysics · Physics 2009-11-10 E. Carretti , G. Bernardi , R. J. Sault , S. Cortiglioni , S. Poppi

Observational evidence for the existence of cosmic magnetic fields in intergalactic space coherent over Mpc scales is presented. Using an unprecedentedly large sample of Faraday rotation measures of radio sources from the NRAO VLA Sky…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-16 Jounghun Lee , Ue-Li Pen , A. Russell Taylor , Jeroen M. Stil , Caleb Sunstrum

The goal of this work is to constrain the strength and structure of the magnetic field associated with the environment of the radio source 3C 449, using observations of Faraday rotation, which we model with a structure function technique…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 D. Guidetti , R. A. Laing , M. Murgia , F. Govoni , L. Gregorini , P. Parma

Preliminary VLBA polarisation results on 6 ``blazars'' from 6.5-cm to 7-mm are presented here. Observing at several different wavelengths, separated by short and long intervals, enabled reliable information about the magnetic (B) field…

Astrophysics · Physics 2007-10-02 Shane P. O'Sullivan , Denise C. Gabuzda

At the center of the Milky Way lurks a unique compact nonthermal radio source, Sgr A*. It is thought to be powered by a 2.6 million solar mass black hole that is accreting the stellar winds from the numerous early-type stars that exist in…

Astrophysics · Physics 2007-05-23 R. F. Coker , S. Markoff
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