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Mass entrainment and turbulence-driven acceleration of ultra-high energy cosmic rays in Centaurus A
(2013-10)
Observations of the FR I radio galaxy Centaurus A in radio, X-ray, and gamma-ray bands provide evidence for lepton acceleration up to several TeV and clues about hadron acceleration to tens of EeV. Synthesising the available ...
A 325-MHz GMRT survey of the Herschel-ATLAS/GAMA fields
(2013-10-01)
We describe a 325-MHz survey, undertaken with the Giant Metrewave Radio Telescope (GMRT), which covers a large part of the three equatorial fields at 9, 12 and 14.5 h of right ascension from the Herschel-Astrophysical ...
The fading of two transient ultraluminous x-ray sources to below the stellar mass Eddington limit
(2013-09-20)
We report new detections of the two transient ultraluminous X-ray sources (ULXs) in NGC 5128 from an ongoing series of Chandra observations. Both sources have previously been observed L (2-3) × ∼10 erg s, at the lower end ...
Synchrotron and inverse-Compton emission from radio galaxies with non-uniform magnetic field and electron distributions
(2013-08)
I investigate the effect of non-uniform magnetic fields in the extended structures of radio galaxies on the observed synchrotron and inverse-Compton emission. On the assumption of an isotropic field, with a given power ...
Herschel-ATLAS/GAMA : the environmental density of far-infrared bright galaxies at z < 0.5
(2013-07)
We compare the environmental and star formation properties of far-infrared detected and non-far-infrared detected galaxies out to z similar to 0.5. Using optical spectroscopy and photometry from the Galaxy And Mass Assembly ...
Radio-Loud Active Galactic Nucleus : is there a link between luminosity and cluster environment?
(2013-06-20)
We present here the first results from the Chandra ERA (Environments of Radio-loud AGN) Large Project, characterizing the cluster environments of a sample of 26 radio-loud active galactic nuclei (AGNs) at z similar to 0.5 ...
Herschel-ATLAS/GAMA: What determines the far-infrared properties of radio galaxies?
(2013-06)
We perform a stacking analysis of Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) data in order to obtain isothermal dust temperatures and rest-frame luminosities at 250 mu m (L-250), for a well-defined sample ...
Episodic radio galaxies J0116-4722 and J1158+2621 : Can we constrain the quiescent phase of nuclear activity?
(2013-04-11)
We present multifrequency radio observations of two well-known episodic Fanaroff-Railey type II (FR II) radio galaxies (J0116-4722 and J1158+2621) and a detailed investigation of the life cycle of episodic radio galaxies ...
Mining the Herschel-astrophysical terahertz large area survey : Submillimetre-selected blazars in equatorial fields
(2013-04-11)
The Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) provides an unprecedented opportunity to search for blazars at sub-mm wavelengths. We cross-matched the Faint Images of the Radio Sky at Twenty-cm (FIRST) ...
Spectral properties of X-ray binaries in Centaurus A
(2013-04-01)
We present a spectral investigation of X-ray binaries (XBs) in NGC 5128 (Cen A), using six 100 ks Chandra observations taken over two months in 2007. We divide our sample into thermally and non-thermally dominated states ...