English
Related papers

Related papers: Radio Galaxy Zoo: Morphological classification by …

200 papers

In this paper, we present the identification of five previously unknown giant radio galaxies (GRGs) using Data Release 1 of the Radio Galaxy Zoo citizen science project and a selection method appropriate to the training and validation of…

Astrophysics of Galaxies · Physics 2020-10-14 H. Tang , A. M. M. Scaife , O. I. Wong , A. D. Kapinska , L. Rudnick , S. S. Shabala , N. Seymour , R. P. Norris

We applied the image-based approach with a convolutional neural network model to the sample of low-redshifts galaxies with $-24^{m}<M_{r}<-19.4^{m}$ from the SDSS DR9. We divided it into two subsamples, SDSS DR9 galaxy dataset and Galaxy…

Astrophysics of Galaxies · Physics 2022-08-04 I. B. Vavilova , V. Khramtsov , D. V. Dobrycheva , M. Yu. Vasylenko , A. A. Elyiv , O. V. Melnyk

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between the optical and radio positions, it will be important to align the GAIA frame and the International Celestial…

Astrophysics · Physics 2009-11-13 Geraldine Bourda , Patrick Charlot , Richard Porcas , Simon Garrington

Radio-loud compact radio sources (CRSs) are characterised by morphological compactness of the jet structure centred on the active nucleus of the galaxy. Most of the local elliptical galaxies are found to host a CRS with nuclear luminosities…

Astrophysics of Galaxies · Physics 2023-07-18 Ranieri D. Baldi

The role played by the large-scale environment on the nuclear activity of radio galaxies (RGs), is still not completely understood. Accretion mode, jet power and galaxy evolution are connected with their large-scale environment from tens to…

High Energy Astrophysical Phenomena · Physics 2019-08-17 F. Massaro , N. Álvarez-Crespo , A. Capetti , R. D. Baldi , I. Pillitteri , R. Campana , A. Paggi

Fanaroff-Riley (FR) type 0 radio galaxies are a subclass of radio-loud active galactic nuclei (AGN) that lack extended kpc-scale jets, different from the classical FRI and FRII radio galaxies. They constitute the most abundant population of…

Astrophysics of Galaxies · Physics 2025-01-08 R. D. Baldi , G. Giovannini , A. Capetti , R. Lico

Using ROSAT observations, we estimate gas pressures in the X-ray-emitting medium surrounding 63 FRII radio galaxies and quasars. We compare these pressures with the internal pressures of the radio-emitting plasma estimated by assuming…

Astrophysics · Physics 2009-10-31 M. J. Hardcastle , D. M. Worrall

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

We describe a new method for identifying and characterizing the thermodynamic state of large samples of evolved galaxy groups at high redshifts using high-resolution, low-frequency radio surveys, such as those that will be carried out with…

Astrophysics of Galaxies · Physics 2017-07-26 J. H. Croston , J. Ineson , M. J. Hardcastle , B. Mingo

We explore the implications of our optical spectroscopic survey of 3CR radio sources with z<0.3 for the unified model (UM) for radio-loud AGN, focusing on objects with a FRII radio morphology. The sample contains 33 high ionization galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Ranieri D. Baldi , Alessandro Capetti , Sara Buttiglione , Marco Chiaberge , Annalisa Celotti

Generation of science-ready data from processed data products is one of the major challenges in next-generation radio continuum surveys with the Square Kilometre Array (SKA) and its precursors, due to the expected data volume and the need…

Instrumentation and Methods for Astrophysics · Physics 2024-02-26 S. Riggi , G. Umana , C. Trigilio , C. Bordiu , F. Bufano , A. Ingallinera , F. Cavallaro , Y. Gordon , R. P. Norris , G. Gürkan , P. Leto , C. Buemi , S. Loru , A. M. Hopkins , M. D. Filipović , T. Cecconello

Large-scale sky surveys at low frequencies, like the LOFAR Two-metre Sky Survey (LoTSS), allow for the detection and characterisation of unprecedented numbers of giant radio galaxies (GRGs, or 'giants'). In this work, by automating the…

With the goal of identifying high redshift radio galaxies with FRI classification, here are presented high resolution, wide-field radio observations, near infra-red and optical imaging and multi-object spectroscopy of two fields of the…

Astrophysics · Physics 2009-11-13 E. E. Rigby , I. A. Snellen , P. N. Best

Based on their differing radio morphologies, powerful radio galaxies can be separated into the Fanaroff-Riley I (FR-I) and II (FR-II) classes. Hybrid morphology radio sources (HyMoRS) contain morphologies consistent with each type of jet on…

Astrophysics of Galaxies · Physics 2022-12-28 Andra Stroe , Victoria Catlett , Jeremy J. Harwood , Tessa Vernstrom , Beatriz Mingo

We obtain a sample of 87 radio-loud QSOs in the redshift range 3.6<z<4.4 by cross-correlating sources in the FIRST radio survey S{1.4GHz} > 1 mJy with star-like objects having r <20.2 in SDSS Data Release 7. Of these 87 QSOs, 80 are…

Astrophysics of Galaxies · Physics 2015-06-23 D. Tuccillo , J. I. Gonzalez-Serrano , C. R. Benn

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between the optical and radio positions, it will be important to align the GAIA frame and the International Celestial…

Astrophysics · Physics 2008-12-18 G. Bourda , P. Charlot , R. Porcas , S. Garrington

We investigate the validity of the quasar - radio galaxy unification scenario and detect dust tori within radio galaxies of various types. Using VISIR on the VLT, we acquired sub-arcsecond (~0.40") resolution N-band images, at a wavelength…

Astrophysics of Galaxies · Physics 2014-11-20 G. van der Wolk , P. D. Barthel , R. F. Peletier , J. W. Pel

The purpose of this work is two-fold: (1) to quantify the occurrence of ultra-steep spectrum remnant FRII radio galaxies in a 74 MHz flux limited sample, and (2) perform Monte-Carlo simulations of the population of active and remnant FRII…

Astrophysics of Galaxies · Physics 2017-08-16 L. E. H. Godfrey , R. Morganti , M. Brienza

($ABRIDGED$) We probe the physical properties and large-scale environment of radio AGN in the faintest FR population to-date, and link them to their radio structure. We use the VLA-COSMOS Large Project at 3 GHz, with resolution and…

This paper presents a detailed analysis of the radio properties for the sample of faint radio sources introduced in Magliocchetti et al. (2000). The sample comprises mainly intrinsically low-power sources whose majority ($\simgt 70$ per…

Astrophysics · Physics 2009-11-07 M. Magliocchetti , A. Celotti , L. Danese