English
Related papers

Related papers: LOFAR low-band antenna observations of the 3C295 a…

200 papers

The jets and lobes of nearby radio galaxies are ideal laboratories to explore the spectral and dynamical evolution of the radio-emitting plasma that emanates from active galactic nuclei. Here, we present a high-resolution radio continuum…

High Energy Astrophysical Phenomena · Physics 2026-04-15 Luca Ricci , Luisa Ostorero , Raffaella Morganti , Judith H. Croston , Martin J. Hardcastle , Timothy W. Shimwell

We present deep multifrequency observations using the Giant Metrewave Radio Telescope at 153, 244, 610 and 1260 MHz of a field centered on J0916+6348, to search for evidence of fossil radio lobes which could be due to an earlier cycle of…

Astrophysics · Physics 2009-11-13 S. K. Sirothia , D. J. Saikia , C. H. Ishwara-Chandra , N. G. Kantharia

Spectra have been obtained with the low-resolution modules of the Infrared Spectrograph (IRS) on the Spitzer Space Telescope (Spitzer) for 58 sources having f$_{\nu}$(24 micron) > 0.75 mJy. Sources were chosen from a survey of 8.2 deg$^{2}$…

The redshifted 21-cm signal of neutral hydrogen from the Epoch of Reionization (EoR) can potentially be detected using low-frequency radio instruments such as the Low-Frequency Array (LOFAR). So far, LOFAR upper limits on the 21-cm signal…

We present one of the deepest radio continuum surveys to date at a wavelength ~1 meter, at 324.5 MHz. The data reduction and analysis are described and an electronic catalog of the sources detected above 5 sigma is presented. We also…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Frazer N. Owen , G. E. Morrison , Matthew D. Klimek , Eric W. Greisen

We report on a time-domain search for pulsars in 44 steep spectrum radio sources originally identified from recent imaging surveys. The time-domain search was conducted at 327 MHz using the Ooty radio telescope, and utilized a semi-coherent…

High Energy Astrophysical Phenomena · Physics 2018-09-05 Yogesh Maan , Cees Bassa , Joeri van Leeuwen , M. A. Krishnakumar , Bhal Chandra Joshi

Aims. An efficient means of locating calibrator sources for International LOFAR is developed and used to determine the average density of usable calibrator sources on the sky for subarcsecond observations at 140 MHz. Methods. We used the…

FRB 20180916B is a well-studied repeating fast radio burst source. Its proximity (~150 Mpc), along with detailed studies of the bursts, have revealed many clues about its nature -- including a 16.3-day periodicity in its activity. Here we…

We present deep polarimetric observations of the European Large Area ISO Survey-North 1 (ELAIS-N1) field using the Low Frequency Array (LOFAR) at 114.9-177.4 MHz. The ELAIS-N1 field is part of the LOFAR Two-metre Sky Survey deep fields data…

Dense aperture arrays provide key benefits in modern astrophysical research. They are flexible, employing cheap receivers, while relying on the ever more sophisticated compute back-end to deal with the complexities of signal processing…

Instrumentation and Methods for Astrophysics · Physics 2022-04-06 A. Shulevski , T. M. O. Franzen , W. L. Williams , T. Vernstrom , B. K. Gehlot , M. Kuiack , R. A. M. J. Wijers

High-redshift quasars are important to study galaxy and active galactic nuclei (AGN) evolution, test cosmological models, and study supermassive black hole growth. Optical searches for high-redshift sources have been very successful, but…

We present parameterized broadband spectral models valid at frequencies between 30-300 MHz for six bright radio sources selected from the 3C survey, spread in Right Ascension from 0-24 hours. For each source, data from the literature are…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Anna M. M. Scaife , George H. Heald

We used the Near Infrared Camera on Keck I to obtain Ks-band images of four candidate high-redshift radio galaxies selected using optical and radio data in the NOAO Deep Wide-Field Survey in Bootes. Our targets have 1.4 GHz radio flux…

We present a sample of 1,483 sources that display spectral peaks between 72 MHz and 1.4 GHz, selected from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. The GLEAM survey is the widest fractional bandwidth…

We have conducted two pilot surveys for radio pulsars and fast transients with the Low-Frequency Array (LOFAR) around 140 MHz and here report on the first low-frequency fast-radio burst limit and the discovery of two new pulsars. The first…

We present an overview of the LOFAR Tied-Array All-Sky Survey (LOTAAS) for radio pulsars and fast transients. The survey uses the high-band antennas of the LOFAR Superterp, the dense inner part of the LOFAR core, to survey the northern sky…

We present the Multifrequency Snapshot Sky Survey (MSSS), the first northern-sky LOFAR imaging survey. In this introductory paper, we first describe in detail the motivation and design of the survey. Compared to previous radio surveys, MSSS…

Instrumentation and Methods for Astrophysics · Physics 2015-11-04 G. H. Heald , R. F. Pizzo , E. Orrú , R. P. Breton , D. Carbone , C. Ferrari , M. J. Hardcastle , W. Jurusik , G. Macario , D. Mulcahy , D. Rafferty , A. Asgekar , M. Brentjens , R. A. Fallows , W. Frieswijk , M. C. Toribio , B. Adebahr , M. Arts , M. R. Bell , A. Bonafede , J. Bray , J. Broderick , T. Cantwell , P. Carroll , Y. Cendes , A. O. Clarke , J. Croston , S. Daiboo , F. de Gasperin , J. Gregson , J. Harwood , T. Hassall , V. Heesen , A. Horneffer , A. J. van der Horst , M. Iacobelli , V. Jelić , D. Jones , D. Kant , G. Kokotanekov , P. Martin , J. P. McKean , L. K. Morabito , B. Nikiel-Wroczyński , A. Offringa , V. N. Pandey , M. Pandey-Pommier , M. Pietka , L. Pratley , C. Riseley , A. Rowlinson , J. Sabater , A. M. M. Scaife , L. H. A. Scheers , K. Sendlinger , A. Shulevski , M. Sipior , C. Sobey , A. J. Stewart , A. Stroe , J. Swinbank , C. Tasse , J. Trüstedt , E. Varenius , S. van Velzen , N. Vilchez , R. J. van Weeren , S. Wijnholds , W. L. Williams , A. G. de Bruyn , R. Nijboer , M. Wise , A. Alexov , J. Anderson , I. M. Avruch , R. Beck , M. E. Bell , I. van Bemmel , M. J. Bentum , G. Bernardi , P. Best , F. Breitling , W. N. Brouw , M. Brüggen , H. R. Butcher , B. Ciardi , J. E. Conway , E. de Geus , A. de Jong , M. de Vos , A. Deller , R. J. Dettmar , S. Duscha , J. Eislöffel , D. Engels , H. Falcke , R. Fender , M. A. Garrett , J. Grießmeier , A. W. Gunst , J. P. Hamaker , J. W. T. Hessels , M. Hoeft , J. Hörandel , H. A. Holties , H. Intema , N. J. Jackson , E. Jütte , A. Karastergiou , W. F. A. Klijn , V. I. Kondratiev , L. V. E. Koopmans , M. Kuniyoshi , G. Kuper , C. Law , J. van Leeuwen , M. Loose , P. Maat , S. Markoff , R. McFadden , D. McKay-Bukowski , M. Mevius , J. C. A. Miller-Jones , R. Morganti , H. Munk , A. Nelles , J. E. Noordam , M. J. Norden , H. Paas , A. G. Polatidis , W. Reich , A. Renting , H. Röttgering , A. Schoenmakers , D. Schwarz , J. Sluman , O. Smirnov , B. W. Stappers , M. Steinmetz , M. Tagger , Y. Tang , S. ter Veen , S. Thoudam , R. Vermeulen , C. Vocks , C. Vogt , R. A. M. J. Wijers , O. Wucknitz , S. Yatawatta , P. Zarka

The Australia Telescope Low-brightness survey (ATLBS; \cite{SESS10}) regions have been mosaic imaged at a radio frequency of 1.4 GHz with $6\arcsec$ angular resolution and 72 $\mu$Jy beam$^{-1}$ rms noise. The images (centered at RA:…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 K. Thorat , R. Subrahmanyan , L. Saripalli , R. D. Ekers

We started a follow-up investigation of the Deep X-ray Radio Blazar Survey objects with declination >-10 deg. We undertook a survey with the EVN at 5GHz to make the first images of a complete sample of weak blazars, aiming at a comparison…

Astrophysics of Galaxies · Physics 2015-04-29 F. Mantovani , M. Bondi , K. -H. Mack , W. Alef , E. Ros , J. A. Zensus
‹ Prev 1 3 4 5 6 7 10 Next ›