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Related papers: The Galactic Centre region

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We have observed a sample of 64 small diameter sources towards the central -6 degree < l< 6 degree, -2 degree < b < 2 degree of the Galaxy with the aim of studying the Faraday rotation measure near the Galactic Centre (GC) region. All the…

Astrophysics · Physics 2008-11-26 Subhashis Roy , A. Pramesh Rao , Ravi Subrahmanyan

To determine the properties of the Faraday screen and the magnetic field near the central region of the Galaxy, we measured the Faraday rotation measure (RM) towards 60 background extragalactic source components through the -6 deg < l <6…

Astrophysics · Physics 2009-11-13 Subhashis Roy , A. Pramesh Rao , Ravi Subrahmanyan

We present new 6 and 20 cm Very Large Array (VLA) observations of polarized continuum emission of roughly 0.5 square degrees of the Galactic center (GC) region. The 6 cm observations detect diffuse linearly-polarized emission throughout the…

Astrophysics of Galaxies · Physics 2015-05-27 C. J. Law , M. A. Brentjens , G. Novak

The central region of the Galaxy has been observed at 580, 620 and 1010 MHz with the Giant Metrewave Radio Telescope (GMRT). We detect emission from Sgr-A*, the compact object at the dynamical centre of the Galaxy, and estimate its flux…

Astrophysics · Physics 2009-11-10 Subhashis Roy , A. Pramesh Rao

To study the strength and structure of the magnetic field in the Galactic centre (GC) we measured Faraday rotation of the radio emission of pulsars which are seen towards the GC. Three of these pulsars have the largest rotation measures…

Astrophysics of Galaxies · Physics 2016-04-20 D. H. F. M. Schnitzeler , R. P. Eatough , K. Ferrière , M. Kramer , K. J. Lee , A. Noutsos , R. M. Shannon

We present the results of a $\lambda$20 cm VLA observation of the compact Galactic center radio source Sgr A$^*$. The scatter-broadened image is elongated in the East-West direction, with an axial ratio of 0.6$\pm$0.05 and a position angle…

Astrophysics · Physics 2007-05-23 F. Yusef-Zadeh W. Cotton M. Wardle F. Melia , D. Roberts

Observing the magnetic fields of low-mass interacting galaxies tells us how they have evolved over cosmic time and their importance in galaxy evolution. We have measured the Faraday rotation of 80 extra-galactic radio sources behind the…

Astrophysics of Galaxies · Physics 2021-12-22 J. D. Livingston , N. M. McClure-Griffiths , S. A. Mao , Y. K. Ma , B. M. Gaensler , G. Heald , A. Seta

We have determined 194 Faraday rotation measures (RMs) of polarized extragalactic radio sources using new, multi-channel polarization observations at frequencies around 1.4 GHz from the Very Large Array (VLA) in the Galactic plane at…

The scattering diameters of Sgr A* and several nearby OH masers (~ 1" at 1 GHz) indicate that a region of enhanced scattering is along the line of sight to the Galactic center. The scattering diameter of an extragalactic source seen through…

Astrophysics · Physics 2009-10-30 T. Joseph W. Lazio , James M. Cordes

The amplitude of the magnetic field near the Galactic Centre has been uncertain by two orders of magnitude for several decades. On a scale of approximately 100 pc fields of approximately 1000 microG have been reported, implying a magnetic…

Astrophysics of Galaxies · Physics 2010-01-11 Roland M. Crocker , David Jones , Fulvio Melia , Jürgen Ott , Raymond J. Protheroe

The absolute position of the compact radio source at the dynamical center of the Galaxy, Sgr A$^*$, was known only to an accuracy of $0.2''$ in spite of its accurate location with respect to near-IR stellar sources to within 30…

Astrophysics · Physics 2009-10-31 F. Yusef-Zadeh , D. Choate , W. Cotton

We have observed the linear polarization of 450 micron continuum emission from the Galactic center, using a new polarimetric detector system that is operated on a 2 m telescope at the South Pole. The resulting polarization map extends ~ 170…

The current state of research of the Galactic magnetic field is reviewed critically. The average (equipartition) strength of the total field derived from radio synchrotron data is 6 +/- 2 muG locally and about 10 +/- 3 muG at 3 kpc Galactic…

Astrophysics · Physics 2021-04-28 Rainer Beck

New observations of Sgr A have been carried out with the VLA using the broadband (2 GHz) continuum mode at 5.5 GHz, covering the central 30 pc region of the RBZ at the Galactic center. Using the MS-MFS algorithms in CASA, we have imaged Sgr…

Astrophysics of Galaxies · Physics 2016-02-17 Jun-Hui Zhao , Mark R. Morris , W. M. Goss

With the Westerbork Synthesis Radio Telescope (WSRT), multi-frequency polarimetric images were taken of the diffuse radio synchrotron background in a region centered on (l,b) = (161,16). The observations were done simultaneously in 5…

Astrophysics · Physics 2011-05-23 Marijke Haverkorn , Peter Katgert , Ger de Bruyn

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

Deep radio observations at 5 and 8 GHz are presented of a complete sample of 11 radio galaxies with redshifts 0.85 < z < 1.5, selected from the 6C sample of Eales. The radio data, taken using the VLA in A, B and C array configurations,…

Astrophysics · Physics 2015-06-24 P. N. Best , S. A. Eales , S. Rawlings , H. J. A. R"ottgering , M. S. Longair

Polarised radio emission from PSR J1745-2900 has already been used to investigate the strength of the magnetic field in the Galactic Centre, close to Sagittarius A*. Here we report how persistent radio emission from this magnetar, for over…

We present 7 mm lambda VLBA observations of the compact nonthermal radio source in the Galactic Center, Sgr A*. These observations confirm the hypothesis that the image of Sgr A* is a resolved elliptical Gaussian caused by the scattering of…

Astrophysics · Physics 2009-10-30 Geoffrey C. Bower , Donald C. Backer

We have observed the Galactic Center (GC) region at 0.154 and 0.255 GHz with the GMRT. A total of 62 compact likely extragalactic sources are detected. Their scattering sizes go down linearly with increasing angular distance from the GC up…

Astrophysics of Galaxies · Physics 2015-06-16 Subhashis Roy
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