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相关论文: Identifying Radio Active Galactic Nuclei with Mach…

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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…

星系天体物理 · 物理学 2020-11-25 E. F. Ocran , A. R. Taylor , M. Vaccari , C. H. Ishwara-Chandra , I. Prandoni , M. Prescott , C. Mancuso

We present a catalogue of local ($z<0.1$) galaxies that contain faint AGN. We select these objects by identifying galaxies that exhibit a significant excess in their radio luminosities, compared to what is expected from the observed levels…

星系天体物理 · 物理学 2018-06-06 E. K. Lofthouse , S. Kaviraj , D. J. B. Smith , M. J. Hardcastle

Identifying active galactic nuclei (AGN) is extremely important for understanding galaxy evolution and its connection with the assembly of supermassive black holes (SMBH). With the advent of deep and high angular resolution imaging surveys…

星系天体物理 · 物理学 2026-02-18 Berta Margalef-Bentabol , Lingyu Wang , Antonio La Marca , Vicente Rodriguez-Gomez

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

The wide-area component of the LOFAR Two-Metre Sky Survey (LoTSS) is currently the largest radio survey ever carried out, and a large fraction of the 4.5 million radio sources it contains have been optically identified with galaxies or…

Radio observations being insensitive to the dust-obscuration, have been exploited to unveil the population of Active Galactic Nuclei (AGN) residing in galaxies with large dust content. In this paper, we investigate the radio characteristics…

星系天体物理 · 物理学 2022-11-22 Abhijit Kayal , Veeresh Singh , C. H. Ishwara Chandra , Yogesh Wadadekar , Sushant Dutta

Blazars are among the most studied sources in high-energy astrophysics as they form the largest fraction of extragalactic gamma-ray sources and are considered prime candidates for being the counterparts of high-energy astrophysical…

We construct a sample of 3,516 radio-loud host galaxies of active galactic nuclei (AGN) from the optical Sloan Digital Sky Survey (SDSS) and Faint Images of the Radio Sky at Twenty cm (FIRST). These have 1.4 GHz luminosities in the range…

宇宙学与河外天体物理 · 物理学 2011-08-17 Elizabeth J. A. Mannering , Diana M. Worrall , Mark Birkinshaw

We extend the Unified Radio Catalog, a catalog of sources detected by various (NVSS, FIRST, WENSS, GB6) radio surveys, and SDSS, to IR wavelengths by matching it to the IRAS Point and Faint Source catalogs. By fitting each NVSS-selected…

星系天体物理 · 物理学 2015-05-20 Igor Moric , Vernesa Smolcic , Amy Kimball , Dominik A. Riechers , Zeljko Ivezic , Nick Scoville

Narrow-line Seyfert 1 (NLS1) galaxies are believed to be active galactic nuclei (AGN) in the early stages of their evolution. Some dozens of them have been found to host relativistic jets, whilst the majority has not even been detected in…

星系天体物理 · 物理学 2022-01-26 Emilia Järvelä , Rohan Dahale , Luca Crepaldi , Marco Berton , Enrico Congiu , Robert Antonucci

Active galactic nuclei (AGN) are typically identified through their distinctive X-ray or radio emissions, mid-infrared (MIR) colors, or emission lines. However, each method captures different subsets of AGN due to signal-to-noise (SNR)…

The current deepest radio surveys detect hundreds of sources per square degree below 0.1mJy. There is a growing consensus that a large fraction of these sources are dominated by star formation although the exact proportion has been debated…

宇宙学与河外天体物理 · 物理学 2009-11-25 Nick Seymour

To understand the cosmic accretion history of supermassive black holes, separating the radiation from active galactic nuclei (AGNs) and star-forming galaxies (SFGs) is critical. However, a reliable solution on photometrically recognising…

The field of radio astronomy is witnessing a boom in the amount of data produced per day due to newly commissioned radio telescopes. One of the most crucial problems in this field is the automatic classification of extragalactic radio…

天体物理仪器与方法 · 物理学 2023-08-04 Abdollah Masoud Darya , Ilias Fernini , Marley Vellasco , Abir Hussain

In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…

宇宙学与河外天体物理 · 物理学 2009-03-25 Pietro M. Reviglio , David J. Helfand

We use machine learning techniques to investigate their performance in classifying active galactic nuclei (AGNs), including X-ray selected AGNs (XAGNs), infrared selected AGNs (IRAGNs), and radio selected AGNs (RAGNs). Using known physical…

Accurate active galactic nucleus (AGN) identifications and spatially resolved host galaxy properties are a powerful combination for studies of the role of AGNs and AGN feedback in the coevolution of galaxies and their central supermassive…

We collect data at all frequencies for the new sources classified as unknown active galactic nuclei (AGNs) in the latest Burst Alert Telescope (BAT) all-sky hard X-ray catalog. Focusing on the 36 sources with measured redshift, we compute…

高能天体物理现象 · 物理学 2021-04-07 Luca Giuliani , Gabriele Ghisellini , Tullia Sbarrato

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

Modern radio telescope surveys, capable of detecting billions of galaxies in wide-field surveys, have made manual morphological classification impracticable. This applies in particular when the Square Kilometre Array Observatory (SKAO)…

星系天体物理 · 物理学 2026-01-09 Philipp Denzel , Manuel Weiss , Elena Gavagnin , Frank-Peter Schilling