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

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We present observational results for extragalactic radio sources with milliarcsecond components, obtained with the 600 meter ring radio telescope RATAN-600 from 1st to 22nd December, 1997. For each source, a six frequency broad band radio…

To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of two flat spectrum radio quasars, 3C 454.3 and 3C 279, plus one BL Lac, S5 0716+714, all of which have been exhibiting remarkably…

We present radio observations at three frequencies and contemporaneous optical monitoring of the peculiar BL Lac object AO 0235+164. During a three-week campaign with the VLA we observed intraday variability in this source and found a…

Located at the center of the Perseus cluster, 3C 84 is an extremely bright and nearby radio galaxy. Because of the strong diffuse thermal emission from the cluster in X-rays, the detailed properties and the origin of a power-law component…

High Energy Astrophysical Phenomena · Physics 2018-10-31 B. Rani , G. M. Madejski , R. F. Mushotzky , C. Reynolds , J. A. Hodgson

We present the results of variability power spectral density (PSD) analysis using multiwavelength radio to GeV\,$\gamma$-ray light curves covering decades/years to days/minutes timescales for the blazars 3C 279 and PKS 1510-089. The PSDs…

The large number of differences between high- and low-redshift radio galaxies have almost all been discovered by looking at the bright 3C sample of radio sources. This has the disadvantage that the strong correlation between radio…

Astrophysics · Physics 2007-05-23 Stephen Eales

In order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5 and 180 micron. Each pair was selected such that both the…

Astrophysics · Physics 2009-11-06 K. Meisenheimer , M. Haas , S. A. H. Müller , R. Chini , U. Klaas , D. Lemke

NGC 3783 was observed for approximately 210ks by Suzaku and in this time showed significant spectral and flux variability at both short (20ks) and long (100ks) time scales. The full observation is found to consist of approximately six…

High Energy Astrophysical Phenomena · Physics 2015-06-03 R. C. Reis , A. C. Fabian , C. S. Reynolds , L. W. Brenneman , D. J. Walton , M. Trippe , J. M. Miller , R. F. Mushotzky , M. A. Nowak

Classical energy detection (ED) methods for cognitive radio (CR) have addressed noise uncertainty as deviations in noise power and signal uncertainty as variability in signal characteristics, which use probabilistic methods and assume fixed…

Information Theory · Computer Science 2026-05-21 Jialiang Fu , Wen-Xuan Lang

The radio emission mechanisms from accreting protoplanets, and their variability, link observations and physical properties. We revisit the variability of the ~343GHz (ALMA Band7) flux density from PDS70c (F_B7). The subtraction of the…

Context: Fast radio bursts are transient radio pulses of extragalactic origin. Their dispersion measure is indicative of the baryon content in the ionized intergalactic medium between the source and the observer. However, inference using…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-12 Stefan Hackstein , Marcus Brüggen , Franco Vazza

In a previous paper we showed that the radio sources selected by combining large areas radio and optical surveys, present a strong deficit of radio emission with respect to 3CR radio-galaxies matched in line emission luminosity. We argued…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Ranieri D. Baldi , Alessandro Capetti

We have acquired radio continuum data between 70\,MHz and 48\,GHz for a sample of 19 southern starburst galaxies at moderate redshifts ($0.067 < z < 0.227$) with the aim of separating synchrotron and free-free emission components. Using a…

The infrared-radio correlation (IRRC) offers a way to assess star formation from radio emission. Multiple studies found the IRRC to decrease with increasing redshift. This may in part be due to the lack of knowledge about the possible radio…

The 100-m Robert C. Byrd Green Bank Telescope (GBT) and the Owens Valley Radio Observatory (OVRO) 40-m radio telescope have been used to conduct a survey of 3165 known extragalactic radio sources over 143 square degrees of the sky. Target…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 B. S. Mason , L. C. Weintraub , J. L. Sievers , J. R. Bond , S. T. Myers , T. J. Pearson , A. C. S. Readhead , M. C. Shepherd

We report on the first simultaneous high-time resolution X-ray and infrared (IR) observations of a neutron star low mass X-ray binary in its hard state. We performed $\approx 2\,$h of simultaneous observations of 4U 1728-34 using…

We present new JVLA multi-frequency measurements of a set of stars in transition from the post-AGB to the Planetary Nebula phase monitored in the radio range over several years. Clear variability is found for five sources. Their light…

Solar and Stellar Astrophysics · Physics 2017-05-03 L. Cerrigone , G. Umana , C. Trigilio , P. Leto , C. S. Buemi , A. Ingallinera

The optical (BVRI) and radio (8.4 GHz) light curves of S5 1803+784 on a time span of nearly 6 years are presented and discussed. The optical light curve showed an overall variation greater than 3 mag, and the largest changes occured in…

Astrophysics · Physics 2009-11-07 R. Nesci , E. Massaro , M. Maesano , F. Montagni , S. Sclavi , T. Venturi , D. Dallacasa , F. D'Alessio

We present a detailed spectral and spatial analysis of the X-ray properties of the compact and unusual radio galaxy 3C 346, combining information from ROSAT and ASCA. The dominant component of X-ray emission (~ 10^44 ergs/s in each of the…

Astrophysics · Physics 2009-10-31 D. M. Worrall , M. Birkinshaw

We investigate the old stellar populations of the 3CR radio galaxies at redshift z ~ 1, using observations made with the Hubble Space Telescope and the United Kingdom InfraRed Telescope. At radii r < 35 kpc, the infrared radial intensity…

Astrophysics · Physics 2007-05-23 P. N. Best , M. S. Longair , H. J. A. Röttgering