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相关论文: Relics of Double Radio Sources

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We present a study of the extended radio emission in a sample of 8434 low redshift (z < 0.35) broad line active galactic nuclei (AGN) from the Sloan Digital Sky Survey (SDSS). To calculate the jet and lobe contributions to the total radio…

宇宙学与河外天体物理 · 物理学 2015-05-20 Stephen E. Rafter , D. Michael Crenshaw , Paul J. Wiita

Study of high-redshift radio galaxies (HzRGs) can shed light on the active galactic nuclei (AGNs) evolution in massive elliptical galaxies. The vast majority of observed high-redshift AGNs are quasars, and there are very few radio galaxies…

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…

天体物理学 · 物理学 2009-11-06 J. Machalski , M. Jamrozy , S. Zola

The cessation of AGN activity in radio galaxies leads to a remnant phase during which jets are no longer sustained, but lobes can be detected for a period of time before they fade away due to radiative and dynamical energy losses. The…

星系天体物理 · 物理学 2022-12-19 Sushant Dutta , Veeresh Singh , C. H. Ishwara Chandra , Yogesh Wadadekar , Abhijit Kayal

We have cross-matched the 1.4 GHz NRAO VLA Sky Survey (NVSS) with the first 210 fields observed in the 2dF Galaxy Redshift Survey (2dFGRS), covering an effective area of 325 square degrees (about 20% of the final 2dFGRS area). This yields a…

In the time domain, the radio sky in particular along the Galactic plane direction may vary significantly because of various energetic activities associated with stars, stellar and supermassive black holes. Using multi-epoch Very Large…

高能天体物理现象 · 物理学 2022-01-12 Jun Yang , Yongjun Chen , Leonid I. Gurvits , Zsolt Paragi , Aiyuan Yang , Xiaolong Yang , Zhiqiang Shen

We have discovered a number of relatively strong radio sources in the field-of-view of SDSS galaxy clusters which present no optical counterparts down to the magnitude limits of the SDSS. The optically faint radio sources appear as…

宇宙学与河外天体物理 · 物理学 2015-05-30 Mercedes E. Filho , Jarle Brinchmann , Catarina Lobo , Sonia Antón

In order to find more examples of the elusive high-redshift molecular absorbers, we have embarked on a systematic discovery program for highly obscured, radio-loud "invisible AGN" using the VLA Faint Images of the Radio Sky at Twenty…

宇宙学与河外天体物理 · 物理学 2015-06-11 T. Yan , J. T. Stocke , J. Darling , F. Hearty

We have used the VLBA at 5 GHz to observe all galaxies with nuclear radio flux densities above 3.5 mJy found in a VLA survey at 15 GHz of a sample of nearby LINER galaxies. All galaxies were detected revealing high brightness temperature…

天体物理学 · 物理学 2009-10-31 Heino Falcke , Neil M. Nagar , Andrew S. Wilson , James S. Ulvestad

We present a multi-wavelength study into the nature of faint radio sources in a deep radio image with the Giant Meterwave Radio Telescope at 612\,MHz covering 1.2 deg$^2$ of the ELAIS N1 region. We detect 2800 sources above…

星系天体物理 · 物理学 2017-04-12 E. F. Ocran , A. R. Taylor , M. Vaccari , D. A. Green

We have identified 7824 radio sources from the 1.4GHz NRAO VLA Sky Survey (NVSS) with galaxies brighter than K=12.75 mag. in the Second Incremental Data Release of the 6dF Galaxy Survey (6dFGS DR2). The resulting sample of redshifts and…

天体物理学 · 物理学 2008-11-26 Tom Mauch , Elaine M. Sadler

We present a sample of 373 peaked-spectrum (PS) sources with spectral peaks around 150MHz, selected using a subset of two LOFAR all-sky surveys, the LOFAR Two Meter Sky Survey and the LOFAR LBA Sky Survey. These surveys are the most…

In order to understand the possible mechanisms of recurrent jet activity in radio galaxies and quasars, which are still unclear, we have identified such sources with a large range of linear sizes (220 $-$ 917 kpc), and hence time scales of…

星系天体物理 · 物理学 2019-07-17 S. Nandi , D. J. Saikia , R. Roy , P. Dabhade , Y. Wadadekar , J. Larsson , M. Baes , H. C. Chandola , M. Singh

We have started a search for High Redshift Radio Galaxies (HZRGs) in an area covering 7 sr by selecting a sample of Ultra Steep Spectrum (USS) sources with a low flux density cut-off S(1400 MHz) > 10 mJy and a steep spectral index cut-off…

天体物理学 · 物理学 2016-01-27 Carlos De Breuck , Wil van Breugel , Huub Rottgering , George Miley

Cheung identified a sample of 100 candidate X-shaped radio galaxies using the NRAO FIRST survey; these are small-axial-ratio extended radio sources with off-axis emission. Here we present radio images of 52 of these sources that have been…

星系天体物理 · 物理学 2015-09-16 David H. Roberts , Jake P. Cohen , Jing Lu , Lakshmi Saripalli , Ravi Subrahmanyan

We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a sample of 81 galaxies that possess double-peaked narrow optical emission line spectra in the Sloan Digital Sky Survey, have two optical AGN emission components…

Basing our analysis on ROGUE I, a catalog of over 32,000 radio sources associated with optical galaxies, we provide two diagnostics to select the galaxies where the radio emission is due to an active galactic nucleus (AGN). Each of these…

We present four Mpc-sized radio galaxies which consist of a pair of double-lobed radio sources, aligned along the same axis, and with a coinciding radio core. We have called these peculiar radio sources `double-double' radio galaxies (DDRG)…

天体物理学 · 物理学 2009-10-31 Arno P. Schoenmakers , A. G. de Bruyn , H. J. A. Rottgering , H. van der Laan , C. R. Kaiser

Radio-emitting active galactic nuclei (AGNs) are common in elliptical galaxies and AGN feedback is one of the possible mechanisms for regulating star formation in massive galaxies. It is unclear if all passive galaxy populations host radio…

星系天体物理 · 物理学 2025-07-16 Hei Yung Chan , Michael J. I. Brown

The radio structures and optical identifications of a sample of 242 sources classified as double-double radio sources by Proctor (2011) from a morphological study of sources in the FIRST (Faint Images of the Radio Sky at Twenty centimeters)…

宇宙学与河外天体物理 · 物理学 2012-08-16 S. Nandi , D. J. Saikia
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