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Related papers: Millijansky Radio Variability in SDSS Stripe 82

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We investigate the long-term variability exhibited by the X-ray point sources in the starburst galaxy M82. By combining 9 Chandra observations taken between 1999 and 2007, we detect 58 X-ray point sources within the D25 isophote of M82 down…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Yi-Kuan Chiang , Albert K. H. Kong

Using 8.4 years of photometry from the AllWISE/NEOWISE multi-epoch catalogs, we compare the mid-infrared variability properties of a sample of 2197 dwarf galaxies (M_stellar < 2 x 10^9 h^-2 M_sun) to a sample of 6591 more massive galaxies…

Astrophysics of Galaxies · Physics 2020-09-09 Nathan Secrest , Shobita Satyapal

We report on two surveys of radio-weak AGN to look for radio variability. We find significant variability with an RMS of 10-20% on a timescale of months in radio-quiet and radio-intermediate quasars. This exceeds the variability of radio…

Astrophysics · Physics 2007-05-23 Heino Falcke , Joseph Lehar , Richard Barvainis , Neil M. Nagar , Andrew S. Wilson

We perform a blind search for the variability of the gamma-ray sky in the energy range E>1 GeV using 308 weeks of the Fermi-LAT data. We use the technique based on the comparison of the weekly photon counts and exposures in sky pixels by…

High Energy Astrophysical Phenomena · Physics 2015-12-22 M. S. Pshirkov , G. I. Rubtsov

We release the next installment of the Stripe 82 X-ray survey point-source catalog, which currently covers 31.3 deg$^2$ of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are significantly…

Since late 2007, we have been monitoring a large sample of known and likely gamma-ray-loud blazars at 15 GHz twice per week with the Owens Valley Radio Observatory (OVRO) 40 m Telescope. Our initial sample included the 1158 sources above…

We positionally match sources observed by the Sloan Digital Sky Survey (SDSS), the Two Micron All Sky Survey (2MASS), and the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. Practically all 2MASS sources are matched to an SDSS…

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

The radio spectral index is a powerful probe for classifying cosmic radio sources and understanding the origin of the radio emission. Combining data at 147 MHz and 1.4 GHz from the TIFR GMRT Sky Survey (TGSS) and the NRAO VLA Sky Survey…

Instrumentation and Methods for Astrophysics · Physics 2018-01-10 F. de Gasperin , H. T. Intema , D. A. Frail

We report the results of $g-$, $r-$, and $i-$dropout selections based on optical identifications of Very Large Array Sky Survey (VLASS) radio sources using the Hyper Suprime-Cam Subaru Strategic Program survey (HSC--SSP). By positional…

We present a search for transient radio sources on timescales of 2 to 9 yr at 150 MHz. This search is conducted by comparing the first Alternative Data Release of the TIFR GMRT Sky Survey (TGSS ADR1) and the second data release of the LOFAR…

We present the first results of an ongoing intra-day variability (IDV) flux density monitoring program of 107 blazars, which were selected from a sample of RadioAstron space very long baseline interferometry (VLBI) targets. The~IDV…

Predictions of the number of faint polarised radio sources that can be detected by SKA pathfinder telescopes and the SKA depend on the polarisation properties of radio sources with a total flux density around 1 mJy. Total intensity source…

Astrophysics · Physics 2009-06-23 J. M. Stil , A. R. Taylor , M. Krause , R. Beck

We present the first results from the Distant Radio Galaxies Optically Non-detected in the SDSS (DRaGONS) Survey. Using a novel selection technique for identifying high redshift radio galaxy (HzRG) candidates, a large sample of bright…

Astrophysics · Physics 2008-11-26 S. J. Schmidt , A. J. Connolly , A. M. Hopkins

We have conducted sensitive (1 sigma<30 uJy) 1.4 GHz radio observations with the Australia Telescope Compact Array of a field largely coincident with infrared observations of the Spitzer Wide-Area Extragalactic Survey. The field is centred…

A new generation of radio telescopes with excellent sensitivity, instantaneous {\it uv} coverage, and large fields of view, are providing unprecedented opportunities for performing commensal transient searches. Here we present such a…

High Energy Astrophysical Phenomena · Physics 2023-09-18 S. I. Chastain , A. J. van der Horst , A. Rowlinson , L. Rhodes , A. Andersson , R. Diretse , R. P. Fender , P. A. Woudt

We present the optical and infrared identifications of the 266 radio sources detected at 20 cm with the Very Large Array in the Chandra Deep Field South (Kellermann et al. 2008). Using deep i-band Advanced Camera for Surveys, R-band Wide…

Variability at all observed wavelengths is a distinctive property of AGN. Hard X-rays provide us with a view of the innermost regions of AGN, mostly unbiased by absorption along the line of sight. Swift/BAT offers the unique opportunity to…

High Energy Astrophysical Phenomena · Physics 2015-06-17 S. Soldi , V. Beckmann , W. H. Baumgartner , G. Ponti , C. R. Shrader , P. Lubinski , H. A. Krimm , F. Mattana , J. Tueller

We use highly spectroscopically complete observations of the radio sources from the VLA 1.4 GHz survey of the HDF-N region to study the faint radio galaxy population and its evolution. We spectrally classify the sources into four spectral…

Astrophysics · Physics 2011-02-11 A. J. Barger , L. L. Cowie , W. -H. Wang

The population of radio-loud stars has to date been studied primarily through either targeted observations of a small number of highly active stars or widefield, single-epoch surveys that cannot easily distinguish stellar emission from…

Solar and Stellar Astrophysics · Physics 2023-12-19 Joshua Pritchard , Tara Murphy , George Heald , Michael S. Wheatland , David L. Kaplan , Emil Lenc , Andrew O'Brien , Ziteng Wang