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Related papers: A search for sub-second radio variability predicte…

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Searches for slow radio transients and variables have generally focused on extragalactic populations, and the basic parameters of Galactic populations remain poorly characterized. We present a large 3 GHz survey performed with the Allen…

(abridged) The results of deep long-slit optical spectroscopy for a sample of 8 6C radio galaxies at z~1 are presented. Emission line ratios are derived for emission lines with rest-frame wavelengths of 1500 - 4500Ang, and the kinematic…

Astrophysics · Physics 2009-11-07 K. J. Inskip , P. N. Best , S. Rawlings , M. S. Longair , G. Cotter , H. J. A. Rottgering , S. Eales

We present low-frequency observations starting from ~150 MHz with the Giant Metrewave Radio Telescope (GMRT), and high-frequency observations with the Very Large Array (VLA) of two large radio galaxies 3C46 and 3C452. These observations…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. Nandi , A. Pirya , S. Pal , C. Konar , D. J. Saikia , M. Singh

Solar radio bursts are strongly affected by radio-wave scattering on density inhomogeneities, changing their observed time characteristics, sizes, and positions. The same turbulence causes angular broadening and scintillation of galactic…

Chandra observations of 17 nearby galaxies were analysed and 166 bright sources with X-ray counts > 100, were chosen for temporal analysis. Fractional root mean square variability amplitudes were estimated for lightcurves binned at ~ 4 ksec…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Soma Mandal , Ranjeev Misra , Gulab Dewangan

We present the results of our study of cross-correlations between long-term multi-band observations of the radio variability of the blazar 3C 279. More than a decade (2008-2022) of radio data were collected at seven different frequencies…

The radio galaxy 3C 84 is a representative of gamma-ray-bright misaligned active galactic nuclei (AGNs) and one of the best laboratories to study the radio properties of the sub-pc jet in connection with the gamma-ray emission. In order to…

We investigate the short-term variability properties and the power spectral density (PSD) of the Broad-Line Radio Galaxy (BLRG) 3C 390.3 using observations made by XMM, RXTE, and Suzaku on several occasions between October 2004 and December…

High Energy Astrophysical Phenomena · Physics 2009-08-06 M. Gliozzi , I. E. Papadakis , M. Eracleous , R. M. Sambruna , D. R. Ballantyne , V. Braito , J. N. Reeves

We suggest that extragalactic radio sources are intermittent on timescales of 10^4-10^5 yr. Using a simple spherical model of a cocoon/shock system, it is found that inactive sources fade rapidly in radio luminosity but the shock in the…

Astrophysics · Physics 2009-10-30 C. S. Reynolds , M. C. Begelman

Stellar coronae have been invoked to explain the apparently extragalactic dispersion measures observed in fast radio bursts. This paper demonstrates that the suggested plasma densities would lead to deviations from the standard dispersion…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-10 Artem V. Tuntsov

Galaxy colours are determined for two samples of 6C and 3CR radio sources at z~1, differing by a factor of ~6 in radio power. Corrections are made for emission line contamination and the presence of any nuclear point source, and the data…

Astrophysics · Physics 2009-11-11 K. J. Inskip , P. N. Best , M. S. Longair

We have undertaken a nearly simultaneous optical/UV and X-ray variability study of the flat spectrum radio quasar, 3C 273 using data available from the XMM$-$Newton satellite mission from June 2000 to July 2012. Here we focus on the…

Astrophysics of Galaxies · Physics 2015-06-02 Nibedita Kalita , Alok C. Gupta , Paul J. Wiita , Jai Bhagwan , Kalpana Duorah

I define 3 samples of extragalactic radio sources of type FRII, containing 26 objects in total. The control sample consists of 6C and 7C sources with radio-luminosities of around 10E27 W\Hz at 151 MHz and z~1. The other samples contain 3CRR…

Astrophysics · Physics 2009-09-29 Julie-Ann Goodlet

Violent multi-wavelength variabilities are observed in gamma-ray-selected blazars. We present an analysis of long-term light curves for eight bright blazars to explore the co-variation pattern in the gamma-ray and radio bands. We extract…

High Energy Astrophysical Phenomena · Physics 2020-05-27 Hai-Ming Zhang , Zhen-Jie Wang , Jin Zhang , Ting-Feng Yi , Liang Chen , Rui-Jing Lu , En-Wei Liang

We have used the VLA to study radio variability among a sample of 18 low luminosity active galactic nuclei (LLAGNs), on time scales of a few hours to 10 days. The goal was to measure or limit the sizes of the LLAGN radio-emitting regions,…

Astrophysics · Physics 2009-11-10 James M. Anderson , James S. Ulvestad

The `radio sky' is relatively unexplored for transient signals, although the potential of radio-transient searches is high, as demonstrated recently by the discovery of a previously unknown type of source which varies on timescales of…

The `missing baryons' of the near universe are believed to be principally in a partially ionized state. Although passing electromagnetic waves are dispersed by the plasma, the effect has hitherto not been utilized as a means of detection…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Richard Lieu , Lingze Duan , T. W. B. Kibble

We present high resolution images of the radio source 3C 84 at 43 GHz, from 121 observations conducted by the BEAM-ME monitoring program between 2010 and 2023. Imaging was performed using the recent forward modeling imaging method…

High Energy Astrophysical Phenomena · Physics 2025-04-02 M. Foschi , J. L. Gómez , A. Fuentes , I. Cho , A. P. Marscher , S. Jorstad

The redshifts of faint radio galaxies identified with giant radio source candidates selected from the sample of Machalski et al. (2001) have been measured. Given the redshift, the projected linear size and radio luminosity are then…

We present the final observations of a complete sample of 37 radio galaxies from the Third Cambridge Catalog (3C) with redshift <0.3 and declination <20 degrees obtained with the VLT/MUSE optical integral field spectrograph. These data were…

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