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Related papers: Radio Linear and Circular Polarization from M81*

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Sgr A*, the massive black hole at the center of the Galaxy, varies in radio through X-ray emission on hourly time scales. The flare activity is thought to arise from the innermost region of an accretion flow onto Sgr A*. We present…

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

We measured the linear polarization of Sagittarius A* to be 7.2 +/- 0.6 % at 230 GHzusing the BIMA array with a resolution of 3.6 x 0.9 arcsec. This confirms the previously reported detection with the JCMT 14-m antenna. Our high resolution…

Astrophysics · Physics 2008-11-26 Geoffrey C. Bower , Melvyn C. H. Wright , Heino Falcke , Donald C. Backer

We have studied the linear polarization of 86 active galactic nuclei (AGN) in the observed frequency range 80-267 GHz (3.7-1.1mm in wavelength), corresponding to rest-frame frequencies 82-738 GHz, with the IRAM Plateau de Bure…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. Trippe , R. Neri , M. Krips , A. Castro-Carrizo , M. Bremer , V. Pietu , A. L. Fontana

The grand-design spiral galaxy M51 was observed with the LOFAR High Frequency Antennas (HBA) and imaged in total intensity and polarisation. This observation covered the frequencies between 115 MHz and 175 MHz. We produced an image of total…

We present new deep multi-frequency radio-polarimetric images of a sample of high redshift radio galaxies (HzRGs), having redshift between 1.7 and 4.1. The radio data at 4.7 and 8.2 GHz were taken with the Very Large Array in the A…

Astrophysics · Physics 2019-08-17 L. Pentericci , W. Van Reeven , C. L. Carilli , H. J. A. Rottgering , G. K. Miley

The central kiloparsec of M81 has been observed in the CO(J=1-0) line and the 3 mm continuum at 100 pc resolution in an attempt to probe molecular gas, and to search for the nuclear inner Lindblad resonance (NILR), around the low-luminosity…

Astrophysics · Physics 2009-11-06 Kazushi Sakamoto , Hiroyuki Fukuda , Keiichi Wada , Asao Habe

We study the exponential scale length of total radio emission, the spectral index distribution, and the linear radio polarization in the Scd galaxy M33. Observations were carried out using the 3.6 cm dual channel and the 6.2 cm four channel…

Astrophysics · Physics 2009-11-13 F. S. Tabatabaei , M. Krause , R. Beck

We report 235 GHz linear and circular polarization (LP and CP) detections of Sgr A* at levels of $\sim10\%$ and $\sim-1\%$, respectively, using ALMA. We describe the first full-Stokes modeling of an observed submillimeter flare with an…

High Energy Astrophysical Phenomena · Physics 2023-02-08 Joseph M. Michail , Farhad Yusef-Zadeh , Mark Wardle , Devaky Kunneriath

We present results of a wideband high-resolution polarization study of Hydra A, one of the most luminous FR I radio galaxies known and amongst the most well-studied. The radio emission from this source displays extremely large Faraday…

Astrophysics of Galaxies · Physics 2023-08-14 Lerato Baidoo , Richard A. Perley , Jean Eilek , Oleg Smirnov , Valentina Vacca , Torsten Ensslin

We report the first detections of circularly polarized emission at submillimeter wavelengths from the compact radio source and supermassive black hole candidate Sgr A* at a level of 1.2\pm0.3% at 1.3 mm wavelength (230 GHz) and 1.6\pm0.3%…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Diego J. Muñoz , Daniel P. Marrone , James M. Moran , Ramprasad Rao

Supernova 1987A in the Large Magellanic Cloud has proven a unique laboratory to investigate particle acceleration in young supernova remnants. Here we report the first detection of linear polarization of the supernova's synchrotron emission…

High Energy Astrophysical Phenomena · Physics 2018-07-18 Giovanna Zanardo , Lister Staveley-Smith , B. M. Gaensler , Remy Indebetouw , C. -Y. Ng , Mikako Matsuura , A. K. Tzioumis

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…

Astrophysics · Physics 2009-11-10 A. L. Cox , L. S. Sparke

The recent detection of significant linear polarization at mm and sub-mm wavelengths in the spectrum of Sgr A* (if confirmed) will be a useful probe of the conditions within several Schwarzschild radii ($r_S$) of the event horizon at the…

Astrophysics · Physics 2009-10-31 Fulvio Melia , Siming Liu , Robert Coker

We have observed the central 45' region of the Galaxy at 620 MHz band of the Giant Metrewave Radio Telescope (GMRT) in radio continuum, and measured the polarisation properties of 64 small diameter background extragalactic sources seen…

Astrophysics · Physics 2007-05-23 Subhashis Roy

The nearby low-luminosity active galactic nucleus (LLAGN) NGC 4258 has a weak radio continuum emission at the galactic center. Quasi-simultaneous multi-frequency observations using the Very Large Array (VLA) from 5 GHz (6 cm) to 22 GHz (1.3…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-29 Akihiro Doi , Kotaro Kohno , Kouichiro Nakanishi , Seiji Kameno , Makoto Inoue , Kazuhiro Hada , Kazuo Sorai

The grand-design face-on spiral galaxy M51 is an excellent laboratory for studying magnetic fields in galaxies. We present new observations of M51 using the VLA at the frequency range of S-band (2-4GHz), to shed new light on the transition…

Astrophysics of Galaxies · Physics 2020-10-21 M. Kierdorf , S. A. Mao , R. Beck , A. Basu , A. Fletcher , C. Horellou , F. Tabatabaei , J. Ott , M. Haverkorn

Radio galaxies are linearly polarized -- an important property that allows us to infer the properties of the magnetic field of the source and its environment. However at low frequencies, Faraday rotation substantially depolarizes the…

We report the detection of variable linear polarization from Sgr A* at a wavelength of 3.5mm, the longest wavelength yet at which a detection has been made. The mean polarization is 2.1 +/- 0.1% at a position angle of 16 +/- 2 deg with rms…

We have previously presented the results of a 325 MHz radio survey of M31, conducted with the A-configuration of the Very Large Array. In this survey, a total of 405 radio sources between <6" and 170" in extent were mapped with a resolution…

Astrophysics · Physics 2009-11-11 Joseph D. Gelfand , T. J. W. Lazio , B. M. Gaensler

The radio source Sgr A* in the Galactic center emits a polarized spectrum at millimeter and sub-millimeter wavelengths that is strongly suggestive of relativistic disk accretion onto a massive black hole. We use the well-constrained mass of…

Astrophysics · Physics 2009-11-06 Benjamin C. Bromley , Fulvio Melia , Siming Liu