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Related papers: The Galactic Centre region

200 papers

G359.87+0.18 is an enigmatic object located 15' from Sgr A*. It has been variously classified as an extragalactic source, Galactic jet source, and young supernova remnant. We present new observations of G359.87+0.18 between 0.33 and 15 GHz…

We present 610 MHz spectropolarimetric images from the Giant Metrewave Radio Telescope (GMRT). We discuss the properties of the GMRT's full-polarisation mode in detail and provide a technical characterisation of the instrument's…

Instrumentation and Methods for Astrophysics · Physics 2013-12-02 J. S. Farnes , D. A. Green , N. G. Kantharia

We present 5, 8, and 15 GHz total intensity and polarimetric observations of the radio source PKS 2322-123 taken with the Very Large Array (VLA). This small (11 kpc) source is located at the center of the cooling-core cluster Abell 2597.…

Astrophysics · Physics 2009-11-10 L. K. Pollack , G. B. Taylor , S. W. Allen

We have modelled the high-energy astrophysics of the inner 200 pc of the Galaxy with a view to explaining the diffuse, broad-band (radio continuum to TeV gamma-ray), non-thermal signal detected from this region. Our modelling pins down the…

High Energy Astrophysical Phenomena · Physics 2011-03-29 Roland M. Crocker

Due to its extraordinarily high concentration of known relativistic particle accelerators such as pulsar wind nebula, supernova remnants, dense molecular cloud regions, and the supermassive black hole (Sgr A*); the center of the Milky Way…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Andrew W. Smith

The Australia Telescope 20 GHz (AT20G) survey is a blind survey of the whole Southern sky at 20 GHz with follow-up observations at 4.8, 8.6, and 20 GHz carried out with the Australia Telescope Compact Array (ATCA). In this paper we present…

The magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of stars. The field associated with ionized…

We present polarisation data for 180 extragalactic sources extracted from the Australia Telescope 20 GHz (AT20G) survey catalog, and observed with the Australia Telescope Compact Array during a dedicated, high sensitivity run. For the sake…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 M. Massardi , S. G. Burke-Spolaor , T. Murphy , R. Ricci , M. Lopez-Caniego , M. Negrello , R. Chhetri , G. De Zotti , R. D. Ekers , R. B. Partridge , E. M. Sadler

We present full-polarisation, broadband observations of the radio galaxy NGC 612 (PKS B0131-637) from 1.3 to 3.1 GHz using the Australia Telescope Compact Array. The relatively large angular scale of the radio galaxy makes it a good…

Astrophysics of Galaxies · Physics 2018-02-07 J. F. Kaczmarek , C. R. Purcell , B. M. Gaensler , X. Sun , S. P. O'Sullivan , N. M. McClure-Griffiths

The large scale magnetic fields of our Galaxy have been mostly revealed by rotation measures ($RM$s) of pulsars and extragalactic radio sources. In the disk of our Galaxy, the average field strength over a few kpc scale is about 1.8 $\mu$G,…

Astrophysics · Physics 2009-10-31 J. L. Han

We explore the magneto-ionic environment of the isolated radio galaxy B2 0755+37 using detailed imaging of the distributions of Faraday rotation and depolarization over the radio source from Very Large Array observations at 1385,1465 and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 D. Guidetti , R. A. Laing , J. H. Croston , A. H. Bridle , P. Parma

Radio-wave scattering is enhanced dramatically for Galactic center sources in a region with radius >~ 15 arc min. Using scattering from Sgr A* and other sources, we show that pulse broadening for pulsars in the Galactic center is {\em at…

Astrophysics · Physics 2009-10-28 James M. Cordes , T. Joseph W. Lazio

Most galactic nuclei are now believed to harbour supermassive black holes. Studies of stellar motions in the central few light-years of our Milky Way Galaxy indicate the presence of a dark object with a mass of about 2.6 million solar…

The BeppoSAX satellite performed a survey of the Galactic Center Region in the 1-10 keV energy band with its Narrow Field Instruments. Several bright X-ray sources containing neutron stars and black holes have been observed and studied,…

Astrophysics · Physics 2009-10-31 L. Sidoli , S. Mereghetti , A. Treves , L. Chiappetti , G. L. Israel , M. Orlandini , ;

We present observations of the region between 5deg < l < 45deg and |b| < 3deg, in the OH 1612 MHz line, taken from 1993 to 1995 with the VLA. These observations are the last part of a larger survey, covering |l| < 45deg and |b| < 3deg, with…

Astrophysics · Physics 2019-08-17 M. Sevenster , H. v. Langevelde , R. Moody , J. Chapman , H. Habing , N. Killeen

We have used polarimetric imaging to study the magneto-ionic medium of the Galaxy, obtaining 1420 MHz images with an angular resolution of 1' over more than 40 square-degrees of sky around the W3/W4/W5/HB3 HII region/SNR complex in the…

Astrophysics · Physics 2009-10-31 A. D. Gray , T. L. Landecker , P. E. Dewdney , A. R. Taylor , A. G. Willis , M. Normandeau

We summarize previous VLBI observations of Sgr A* at millimeter wavelengths and present new results from VLBI observations at 86 and at 215 GHz. At 86 GHz the measured closure phase is close to zero, consistent with a point-like or…

Astrophysics · Physics 2007-05-23 T. P. Krichbaum , A. Witzel , J. A. Zensus

We discuss a high resolution (FWHM~ 0.45 arcsec) image of the emissive polarization from warm dust in the minispiral in the Galactic Centre and discuss the implications for the magnetic field in the dusty filaments. The image was obtained…

Astrophysics of Galaxies · Physics 2018-08-01 P. F. Roche , E. Lopez-Rodriguez , C. M. Telesco , R. Schodel , C. Packham

This paper introduces a new program to find high-redshift radio galaxies in the southern hemisphere through ultra-steep spectrum (USS) selection. We define a sample of 234 USS radio sources with spectral indices alpha_408^843 < -1.0 and…

Astrophysics · Physics 2009-11-13 J. W. Broderick , J. J. Bryant , R. W. Hunstead , E. M. Sadler , T. Murphy

The forthcoming new-generation radio telescope SKA (Square Kilometre Array) and its precursors will provide a rapidly growing number of polarized radio sources. Our analysis aims on what can be learned from these sources concerning the…

Astrophysics · Physics 2009-11-13 Rodion Stepanov , Tigran G. Arshakian , Rainer Beck , Peter Frick , Marita Krause