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Related papers: Radio Linear and Circular Polarization from M81*

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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

We conducted a Very Large Array survey of eleven low luminosity active galactic nuclei for linear and circular polarization at 8.4 GHz. We detected circular polarization in one source (M81*) and linear polarization in 3 sources. Sensitivity…

Astrophysics · Physics 2009-11-07 Geoffrey C. Bower , Heino Falcke , Richard R. Mellon

Sgr A* is variable at radio and submillimeter wavelengths on hourly time scales showing time delays between the peaks of flare emission as well as linearly polarized emission at millimeter and sub-mm wavelengths. To determine the…

Astrophysics · Physics 2009-11-13 F. Yusef-Zadeh , M. Wardle , W. D. Cotton , C. O. Heinke , D. A. Roberts

We describe recent results for Sgr A*, M81* and other low luminosity active galactic nuclei. We have conducted linear and circular polarimetry over a frequency range of 1.4 to 230 GHz and detected a variety of phenomena. The polarization…

Astrophysics · Physics 2009-11-07 Geoffrey C. Bower

We summarize the current state of polarization observations of Sagittarius A*, the compact radio source and supermassive black hole candidate in the Galactic Center. These observations are providing new tools for understanding accretion…

Astrophysics · Physics 2007-05-23 Geoffrey C. Bower

We report here multi-epoch, multi-frequency observations of the circular polarization in Sagittarius A*, the compact radio source in the Galactic Center. Data taken from the VLA archive indicate that the fractional circular polarization at…

Astrophysics · Physics 2009-11-07 Geoffrey C. Bower , Heino Falcke , Robert J. Sault , Donald C. Backer

The radio source M81* at the core of the nearby spiral galaxy M81 is a low-luminosity active galactic nucleus. The close distance of 3.63Mpc allows its morphology to be studied in great detail. Here we present preliminary results from…

Astrophysics · Physics 2008-11-27 Eduardo Ros , Miguel-Angel Perez-Torres

The nearby spiral galaxy M81 harbors in its core a Low-Luminosity AGN (LLAGN), and appears closely related to the more distant and powerful AGNs seen in quasars and radio galaxies. The intrinsic size of this object is unknown due to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 E. Ros , M. A. Perez-Torres

We report on high angular resolution polarimetric observations of the nearby radio galaxy M87 using the Very Long Baseline Array at 24 GHz ($\lambda=$1.3 cm) and 43 GHz ($\lambda=$7 mm) in 2017-2018. New images of the linear polarization…

Astrophysics of Galaxies · Physics 2020-06-15 E. V. Kravchenko , M. Giroletti , K. Hada , D. L. Meier , M. Nakamura , J. Park , R. C. Walker

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…

Astrophysics · Physics 2009-10-31 Geoffrey C. Bower , Donald C. Backer , Jun-Hui Zhao , Miller Goss , Heino Falcke

We report here the detection of circular polarization in the Galactic Center black hole candidate, Sagittarius A*. The detection was made at 4.8 GHz and 8.4 GHz with the Very Large Array. We find that the fractional circular polarization at…

Astrophysics · Physics 2009-10-31 Geoffrey C. Bower , Heino Falcke , Donald C. Backer

There are still many open questions as to the physical mechanisms at work in Low Luminosity AGN that accrete in the extreme sub-Eddington regime. Simultaneous multi-wavelength studies have been very successful in constraining the properties…

Astrophysics · Physics 2015-06-24 R. Schoedel , M. Krips , S. Markoff , R. Neri , A. Eckart

Polarization measurements at low radio frequencies allow detection of small Faraday rotation measures caused by regular magnetic fields in galaxies and in the foreground of the Milky Way. The galaxy M31 was observed in two overlapping…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 René Gießübel , George Heald , Rainer Beck , Tigran Arshakian

We report on VLBI observations of M81*, the northwest-southeast oriented nuclear core-jet source of the spiral galaxy M81, at five different frequencies between 1.7 and 14.8 GHz. By phase referencing to supernova 1993J we can accurately…

Astrophysics · Physics 2009-11-10 M. F. Bietenholz , N. Bartel , M. P. Rupen

Our aim is to characterize the polarized continuum emission properties including intensity, polarization position angle, and polarization percentage of Sgr A* at $\sim$100 (3.0 mm), $\sim$230 (1.3 mm), $\sim$345 (0.87 mm), $\sim$500 (0.6…

M81 is the nearest galaxy with an active galactic nucleus, with the possibly exception of Cen A. The nucleus is exceptionally compact. Here we present results from new VLA and VLBI observations of the nucleus of M81. The VLA shows that its…

Astrophysics · Physics 2008-02-03 M. F. Bietenholz , N. Bartel , M. P. Rupen

We report results from a deep polarization imaging of the nearby radio galaxy 3C$\,$84 (NGC$\,$1275). The source was observed with the Global Millimeter VLBI Array (GMVA) at 86$\,$GHz at an ultra-high angular resolution of $50\mu$as…

We present a statistical analysis of polarized near-infrared (NIR) light from Sgr A*, the radio source associated with the supermassive black hole at the center of the Milky Way. The observations have been carried out using the adaptive…

We report here BIMA array observations of linear polarization in Sagittarius A*, the compact radio source in the Galactic Center. These observations had a resolution of 20 arcsec x 5 arcsec oriented North-South. We do not detect linear or…

Astrophysics · Physics 2009-11-06 Geoffrey C. Bower , Melvyn C. H. Wright , Heino Falcke , Donald C. Backer

We have proposed previously that Sgr A* is simply a scaled down AGN with a black hole, an accretion disk and a radio jet operating at a very low power. It appears as if M81* - the nuclear source in the nearby galaxy M81 - is an ideal…

Astrophysics · Physics 2007-05-23 Heino Falcke
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