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Related papers: Variability of sub-mJy radio sources

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We have produced sensitive, high-resolution radio maps of 12 SMGs in the Lockman Hole using combined MERLIN and VLA data at a frequency of 1.4 GHz. Integrating for 350hr yielded an r.m.s. noise of 6.0 uJy/beam and a resolution of 0.2-0.5".…

Astrophysics · Physics 2009-11-13 A. D. Biggs , R. J. Ivison

We have obtained a deep radio image with the Very Large Array at 6 cm in the Lockman Hole. The noise level in the central part of the field is about 11 microJy. From these data we have extracted a catalogue of 63 radio sources. The analysis…

Astrophysics · Physics 2009-11-07 P. Ciliegi , G. Zamorani , G. Hasinger , I. Lehmann , G. P. Szokoly , G. Wilson

The Lockman Hole is a well-studied extragalactic field with extensive multi-band ancillary data covering a wide range in frequency, essential for characterising the physical and evolutionary properties of the various source populations…

We use archival data from the Phoenix Deep Survey to investigate the variable radio source population above 1mJy/beam at 1.4GHz. Given the similarity of this survey to other such surveys we take the opportunity to investigate the…

Astrophysics of Galaxies · Physics 2016-08-03 Paul Hancock , Jason Drury , Martin Bell , Tara Murphy , Bryan Gaensler

This paper is part of a series discussing the results obtained in the framework of a wide international collaboration - the Lockman Hole Project - aimed at improving the extensive multiband coverage available in the Lockman Hole region,…

Astrophysics of Galaxies · Physics 2018-10-17 I. Prandoni , G. Guglielmino , R. Morganti , M. Vaccari , A. Maini , H. J. A. Rottgering , M. J. Jarvis , M. A. Garrett

Radio source counts constrain galaxy populations and evolution, as well as the global star formation history. However, there is considerable disagreement among the published 1.4-GHz source counts below 100 microJy. Here we present a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 T. Vernstrom , Douglas Scott , J. V. Wall , J. J. Condon , W. D. Cotton , E. B. Fomalont , K. I. Kellermann , N. Miller , R. A. Perley

We describe multi-frequency data designed to probe the emission mechanism that dominates in faint radio sources. Our analysis is based on observations of the Lockman Hole using the GMRT - the deepest 610-MHz imaging yet reported - together…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Edo Ibar , R. J. Ivison , A. D. Biggs , D. V. Lal , P. N. Best , D. A. Green

We present a three epoch survey for transient and variables in the extended Chandra Deep Field South at 5.5 GHz with the Australia Telescope Compact Array. A region covering $\sim$0.3 deg$^{2}$ was observed on timescales of 2.5 months and…

Astrophysics of Galaxies · Physics 2015-06-17 M. E. Bell , M. T. Huynh , P. Hancock , Tara Murphy , B. M. Gaensler , D. Burlon , C. Trott , K. Bannister

The mJy variable extragalactic radio sky is known to be broadly non-changing with approximately $3\%$ of persistent radio sources exhibiting variability which is largely AGN-related. In the faint (<mJy) flux density regime, it is widely…

We present further observations of the Lockman Hole field, made with the Giant Metrewave Radio Telescope at 610 MHz with a resolution of 6 x 5 arcsec^2. These complement our earlier observations of the central approx 5 deg^2 by covering a…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-11 T. S. Garn , D. A. Green , J. M. Riley , P. Alexander

Variability of a galaxy's core radio source can be a significant consequence of AGN accretion. However, this variability has not been well studied, particularly at high radio frequencies. As such, we report on a campaign monitoring the high…

We investigate the radio properties of a sample of 53 sources selected at 850 $\mu$m from the SCUBA-2 Cosmology Legacy Survey using new deep, low-frequency radio imaging of the Lockman Hole field from the Low Frequency Array. Combining…

The degree of beaming in Gamma-Ray Bursts (GRBs) is currently unknown. The uncertainty in the gamma-ray beaming angle, theta, leaves the total energy release (proportional to theta^2) and the event rate per galaxy (proportional to…

Astrophysics · Physics 2009-10-31 Rosalba Perna , Abraham Loeb

We present a study of the 1173 sources brighter than $S_{1.4\,\rm GHz}= 120\,\mu$Jy detected over an area of $\simeq 1.4\,\hbox{deg}^{2}$ in the Lockman Hole field. Exploiting the multi-band information available in this field for $\sim$79%…

Astrophysics of Galaxies · Physics 2020-12-08 Matteo Bonato , Isabella Prandoni , Gianfranco De Zotti , Marisa Brienza , Raffaella Morganti , Mattia Vaccari

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 aim to study the nature of the faint, polarised radio source population whose source composition and redshift dependence contain information about the strength, morphology, and evolution of magnetic fields over cosmic timescales. We use…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 A. Berger , B. Adebahr , N. Herrera Ruiz , A. H. Wright , I. Prandoni , R. -J. Dettmar

We present observations of the Lockman Hole with the Giant Metrewave Radio Telescope (GMRT). Twelve pointings were observed, covering a total area of ~ five square degrees with a resolution of 6 x 5 arcsec, position angle +45deg. The…

Astrophysics · Physics 2009-11-13 Timothy Garn , David A. Green , Julia M. Riley , Paul Alexander

Observational studies of GHz peaked spectrum (GPS) sources contribute to the understanding of the radiative properties and interstellar environment of host galaxies. We present the results from the multi-frequency high-resolution VLBI…

High Energy Astrophysical Phenomena · Physics 2023-03-07 Xiaopeng Cheng , Tao An , Ailing Wang , Sumit Jaiswal

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

We report multiple epoch VLA/JVLA observations of 89 northern hemisphere sources, most with 37\,GHz flux density > 1 Jy, observed at 4.8, 8.5, 33.5, and 43.3 GHz. The high frequency selection leads to a predominantly flat spectrum sample,…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-21 Noah Kurinsky , Anna Sajina , Bruce Partridge , Steve Myers , Xi Chen , Marcos López-Caniego
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