English
Related papers

Related papers: High Frequency Peakers: Baby Radio Sources?

200 papers

Historically, the blazar population has been poorly understood at low frequencies because survey sensitivity and angular resolution limitations have made it difficult to identify megahertz counterparts. We used the LOFAR Two-Metre Sky…

Extragalactic peaked-spectrum radio sources are thought to be the progenitors of larger, radio-loud active galactic nuclei (AGN). Synchrotron self-absorption (SSA) has often been identified as the cause of their spectral peak. The…

Astrophysics of Galaxies · Physics 2019-08-07 M. A. Keim , J. R. Callingham , H. J. A. Röttgering

We discuss our current understanding of the nature of the faint, high-frequency radio sky. The Tenth Cambridge (10C) survey at 15.7 GHz is the deepest high-frequency radio survey to date, covering 12 square degrees to a completeness limit…

Astrophysics of Galaxies · Physics 2016-03-01 Imogen H. Whittam , Julia M. Riley , David A. Green , Matt J. Jarvis

We present the first results from a study of the radio continuum properties of galaxies in the 2dF Galaxy Redshift Survey, based on thirty 2dF fields covering a total area of about 100 square degrees. About 1.5% of galaxies with b(J) < 19.4…

Astrophysics · Physics 2015-06-24 Elaine M. Sadler , V. J. McIntyre , C. A. Jackson , R. D. Cannon

The relation between star formation rates and stellar masses, i.e. the galaxy main sequence, is a useful diagnostic of galaxy evolution. We present the distributions relative to the main sequence of 55 optically-selected PG and 12…

Astrophysics of Galaxies · Physics 2016-03-23 Zhoujian Zhang , Yong Shi , George H. Rieke , Xiaoyang Xia , Yikang Wang , Bingqing Sun , Linfeng Wan

A new sample of very large angular size radio sources has been selected from the 1.4 GHz VLA surveys: FIRST and NVSS. This sample will be very useful for an observational constraint on the time evolution of double radio sources, especially…

Astrophysics · Physics 2009-11-06 J. Machalski , M. Jamrozy , S. Zola

We present the result of 27 ASCA observations of 26 radio-quiet quasars (RQQs) from the PG survey. All the RQQs were detected except 2 BALQSOs. We find the variability characteristics of the sources to be consistent with Seyf-1s. A powerlaw…

Astrophysics · Physics 2009-10-31 I. M. George , T. J. Turner , T. Yaqoob , H. Netzer , A. Laor , R. F. Mushotzky , K. Nandra , T. Takahashi

We present a study of the radio and optical properties of the high-frequency peaker (HFP) blazar PKS 1614+051 at $z=3.21$ based on the data covering the time period of 1997-2024. The radio data are represented by the almost instantaneous…

The redshift distribution of flat-spectrum radio sources with 5 GHz flux densities S>5 mJy is a key component in using current radio lens surveys to probe the cosmological model. We have constructed the first flat-spectrum radio sample in…

Astrophysics · Physics 2009-11-07 J. A. Munoz , E. E. Falco , C. S. Kochanek , J. Lehar , E. Mediavilla

We present the results of Karl G. Jansky Very Large Array (VLA) observations to study the properties of FR0 radio galaxies, the compact radio sources associated with early-type galaxies which represent the bulk of the local radio-loud AGN…

Astrophysics of Galaxies · Physics 2018-11-28 Ranieri D. Baldi , Alessandro Capetti , Gabriele Giovannini

A complete, flux density limited sample of 96 faint ($> 0.5$ mJy) radio sources is selected from the 10C survey at 15.7 GHz in the Lockman Hole. We have matched this sample to a range of multi-wavelength catalogues, including SERVS, SWIRE,…

Astrophysics of Galaxies · Physics 2015-09-30 I. H. Whittam , J. M. Riley , D. A. Green , M. J. Jarvis , M. Vaccari

We have conducted an optical study of the environments of seven radio-loud quasars at redshifts 1<z<1.6. In this paper we describe deep B and R band images obtained for fields of $\sim6\times$6 arcmin around these quasars with 3$\sigma$…

Astrophysics · Physics 2007-05-23 S. F. Sanchez , J. I. Gonzalez-Serrano

We report MIPS photometry of 20 radio-loud quasars and galaxies at 24 and 70 um (and of five at 160 um). We combine this sample with additional sources detected in the far infrared by IRAS and ISO for a total of 47 objects, including 23…

We report the radio continuum properties for several samples of peaked spectrum (PS) radio sources. Broadband spectra of the objects were analysed using the RATAN-600 six-frequency (1.2-22 GHz) observations and available literature data,…

Astrophysics of Galaxies · Physics 2021-11-10 Yu. Sotnikova , T. Mufakharov , M. Mingaliev , A. Mikhailov

A wide range of phenomena, from explosive transients to active galactic nuclei, exhibit variability at radio wavelengths on timescales of a few years. Characterizing the rate and scale of variability in the radio sky can provide keen…

Astrophysics of Galaxies · Physics 2026-05-21 Yjan A. Gordon , Peter S. Ferguson , Michael N. Martinez , Eric J. Hooper

We investigate the nuclear environment of galaxies with observed 22 GHz water megamaser in their subparsec edge-on accretion disks, using 33 GHz (9mm) radio continuum data from VLA, with a resolution of ~ 0.2-0.5 arcsecs, and relate the…

The regular monitoring of flat-spectrum radio quasars (FSRQs) in $\gamma$-rays by Fermi-LAT since past 12 years indicated six sources who exhibited extreme $\gamma$-ray outbursts crossing daily flux of $10^{-5}$ photons/cm$^{2}$/s. We…

High Energy Astrophysical Phenomena · Physics 2021-04-20 Abhradeep Roy , Sonal R. Patel , Arkadipta Sarkar , Anshu Chatterjee , Varsha R. Chitnis

Data from a recent Australia Telescope Compact Array (ATCA) program of multi-frequency, multi-epoch monitoring of 202 active galactic nuclei with declinations < +10 degrees have been searched for GHz Peaked Spectrum (GPS) and Compact Steep…

Astrophysics · Physics 2009-11-10 P. G. Edwards , S. J. Tingay

We present results from the Very Long Baseline Array (VLBA) multi-frequency (1.6, 4.4, 8.6, 22 GHz), high-sensitivity (~25 microJy beam^-1), sub-parsec scale (<1 pc) observations and Spectral Energy Distributions (SEDs) for a sample of 12…

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