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We analyze the optical spectra of massive (log M*/Msun > 11.4) radio-loud galaxies at z~0.2 and z~0.6. By comparing stellar population parameters of these radio-loud samples with radio-quiet control samples, we investigate how the presence…

Narrow-line Seyfert 1 galaxies (NLS1) are an intriguing subclass of active galactic nuclei. Their observed properties indicate low central black hole mass and high accretion rate. The extremely radio-loud NLS1 sources often show…

Astrophysics of Galaxies · Physics 2017-11-07 K. É. Gabányi , S. Frey , Z. Paragi , E. Järvelä , T. Morokuma , T. An , M. Tanaka , I. Tar

Context: Recent XMM-Newton observations have revealed that IRAS 17020+4544 is a very unusual example of black hole wind-produced feedback by a moderately luminous AGN in a spiral galaxy. Aims: Since the source is known for being a radio…

Astrophysics of Galaxies · Physics 2017-04-12 M. Giroletti , F. Panessa , A. L. Longinotti , Y. Krongold , M. Guainazzi , E. Costantini , M. Santos-Lleo

Using empty-field `Quick Look' images from the first two epochs of the VLA Sky Survey (VLASS) observations, centred on the positions of $\sim3700$ individually radio-non-detected active galactic nuclei (AGNs) at $z\ge4$, we performed image…

Astrophysics of Galaxies · Physics 2023-11-03 Krisztina Perger , Sándor Frey , Krisztina É. Gabányi

We present e-MERLIN and EVN observations which reveal unambiguous jet activity within radio quiet quasar HS~0810+2554. With an intrinsic flux density of 880~nJy, this is the faintest radio source ever imaged. The findings present new…

Astrophysics of Galaxies · Physics 2019-03-06 P. Hartley , N. Jackson , D. Sluse , H. R. Stacey , H. Vives-Arias

We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio…

We present a survey of X-ray point sources in a 91 ksec Chandra ACIS-S observation of the z=0.83 cluster MS1054-0321. We detect 47 X-ray sources within the 8.3 arcmin by 8.3 arcmin field, of which two are immediately confirmed from…

Astrophysics · Physics 2009-11-07 O. Johnson , P. N. Best , O. Almaini

We report the results of high-resolution 5 GHz Very Long Baseline Array and European VLBI Network observations of 36 nearby galaxies, an extension of the Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies (LeMMINGs) survey. Our sample…

High Energy Astrophysical Phenomena · Physics 2025-02-19 Xiaopeng Cheng , Tao An , Willem Baan , Raneri D. Baldi , David R. A. Williams-Baldwin , Bong Won Sohn , Robert Beswick , Ian M. Mchardy

Active galactic nuclei (AGNs) make up about 35 per cent of the more than 250 sources detected in very-high-energy (VHE) gamma rays to date with Imaging Atmospheric Cherenkov Telescopes. Apart from four nearby radio galaxies and two AGNs of…

We study the cosmic evolution of radio sources out to $z \simeq 1.5$ using a GMRT 610 MHz survey covering $\sim$1.86 deg$^2$ of the ELAIS N1 field with a minimum/median rms noise 7.1/19.5\,$\mu$Jy / beam and an angular resolution of…

Astrophysics of Galaxies · Physics 2020-11-25 E. F. Ocran , A. R. Taylor , M. Vaccari , C. H. Ishwara-Chandra , I. Prandoni , M. Prescott , C. Mancuso

This is the first of a series of three papers exploring the connection between the multiwavelength properties of AGNs in nearby early-type galaxies and the characteristics of their hosts. We selected two samples, both with high resolution 5…

Astrophysics · Physics 2009-11-13 Alessandro Capetti , Barbara Balmaverde

Identifying the source population of ionizing radiation, responsible for the reionization of the universe, is currently a hotly debated subject with conflicting results. Studies of faint, high-redshift star-forming galaxies, in most cases,…

Astrophysics of Galaxies · Physics 2018-12-12 K. Boutsia , A. Grazian , E. Giallongo , F. Fiore , F. Civano

We study the nature of the faint radio source population detected in the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Early Science data in the COSMOS field, focusing on the properties of the radio-loud active…

In this Letter, we report the discovery of a radio halo in the high-redshift galaxy cluster PSZ2 G099.86+58.45 ($z=0.616$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz. This is one of the most distant radio halos discovered so far.…

Centaurus A, at a distance of less than 4 Mpc, is the nearest radio-loud AGN. Its emission is detected from radio to very-high energy gamma-rays. Despite the fact that Cen A is one of the best studied extragalactic objects the origin of its…

High Energy Astrophysical Phenomena · Physics 2015-05-14 H. Steinle

We present an analysis of the AGN broad-line regions of 6 powerful radio galaxies at z>~2 (HzRGs) with rest-frame optical imaging spectroscopy obtained at the VLT. All galaxies have luminous (L(H-alpha)=few x 10^44 erg s^-1), spatially…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Nicole P. H. Nesvadba , Carlos De Breuck , Matt D. Lehnert , Philip N. Best , Luc Binette , Daniel Proga

The results of Chandra snapshot observations of 11 LINERs (Low-Ionization Nuclear Emission-line Regions), three low-luminosity Seyfert galaxies, and one HII-LINER transition object are presented. Our sample consists of all the objects with…

Astrophysics · Physics 2010-04-06 Yuichi Terashima , Andrew S. Wilson

We report a serendipitous discovery of six very low-luminosity active galactic nuclei (AGNs) only by optical variability in one-month baseline. The detected flux variability is ~ 1-5% of the total luminosity of host galaxies. Careful…

Astrophysics · Physics 2009-11-10 Tomonori Totani , Takahiro Sumi , George Kosugi , Naoki Yasuda , Mamoru Doi , Takeshi Oda

The central nuclei of galaxies, where super-massive black holes (SMBHs) are thought to reside, can experience phases of activity when they become Active Galactic Nuclei (AGN). An AGN can eject winds, jets, and produce radiation across the…

Astrophysics of Galaxies · Physics 2019-02-18 Francesca Panessa , Ranieri D. Baldi , Ari Laor , Paolo Padovani , Ehud Behar , Ian McHardy
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