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相关论文: Kpc-scale radio-jets in narrow-line Seyfert 1 gala…

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In recent years, several Radio-Loud Narrow-Line Seyfert 1 galaxies (RL-NLS1) possessing relativistic jets have come into attention with their detections in Very Large Baseline Array (VLBA) and in $\gamma$-ray observations. In this paper we…

星系天体物理 · 物理学 2018-07-09 Veeresh Singh , Hum Chand

We report the finding of kiloparsec (kpc)-scale radio structures in three radio-loud narrow-line Seyfert 1 (NLS1) galaxies from the Faint Images of the Radio Sky at Twenty-centimeters (FIRST) of the Very Large Array (VLA), which increases…

星系天体物理 · 物理学 2015-06-11 Akihiro Doi , Hiroshi Nagira , Nozomu Kawakatu , Motoki Kino , Hiroshi Nagai , Keiichi Asada

Narrow-line Seyfert 1 (NLS1) galaxies are a type of active galactic nuclei (AGN) that were originally classified as sources with little to no radio emission. Although the class is rather unified from an optical perspective, their radio…

星系天体物理 · 物理学 2025-11-26 I. Varglund , E. Järvelä , M. J. Hardcastle , S. Varglund , A. Lähteenmäki

Narrow-line Seyfert 1 galaxies (NLS1) are active galactic nuclei (AGN) known to have small masses of the central black hole and high accretion rates. NLS1s are generally radio-quiet, but a small part of them (about 7\%) are radio-loud. The…

星系天体物理 · 物理学 2016-02-25 M. Berton , L. Foschini , A. Caccianiga , J. L. Richards , S. Ciroi , E. Congiu , V. Cracco , G. La Mura , L. Marafatto , P. Rafanelli

Seyfert galaxies commonly host compact jets spanning 10-100 pc scales, but larger structures (KSRs) are resolved out in long baseline, aperture synthesis surveys. We report a new, short baseline Very Large Array (VLA) survey of a complete…

天体物理学 · 物理学 2008-11-26 J. F. Gallimore , D. J. Axon , C. P. O'Dea , S. A. Baum , A. Pedlar

Seyfert and LINER galaxies are known to exhibit compact radio emission on $\sim$ 10 to 100 parsec scales, but larger Kiloparsec-Scale Radio structures (KSRs) often remain undetected in sub-arcsec high resolution observations. We investigate…

星系天体物理 · 物理学 2014-10-13 Veeresh Singh , C. H. Ishwara-Chandra , Yogesh Wadadekar , Alexandre Beelen , Preeti Kharb

Narrow-line Seyfert 1 (NLS1) galaxies are active galactic nuclei (AGN) believed to be in the early stages of their evolution. A fraction of them have been found to host relativistic jets. Due to the lack of large-scale diffuse radio…

星系天体物理 · 物理学 2021-08-20 Emilia Järvelä , Marco Berton , Luca Crepaldi

Narrow-line Seyfert 1 galaxies (NLS1s) are active galactic nuclei (AGN) recently identified as a new class of $\gamma$-ray sources. The high energy emission is explained by the presence of a relativistic jet observed at small angles, just…

Narrow-line Seyfert 1 galaxies (NLS1s), a subclass of active galactic nuclei (AGNs) at early stage of accretion process, are also found to host relativistic jets. However, currently known jetted NLS1s are rare. The majority of NLS1s are…

星系天体物理 · 物理学 2024-02-23 Xu-Liang Fan

We present the first systematic study of (non-radio-selected) radio-loud narrow-line Seyfert 1 (NLS1) galaxies. Cross-correlation of the `Catalogue of Quasars and Active Nuclei' with several radio and optical catalogues led to the…

天体物理学 · 物理学 2008-11-26 S. Komossa , W. Voges , D. Xu , S. Mathur , H. -M. Adorf , G. Lemson , W. Duschl , D. Grupe

The last decade has witnessed a steadily increasing number of observational studies concerning the rare class of radio loud narrow-line Seyfert 1 galaxies, of which several hundred are currently known. According to the current AGN paradigm,…

星系天体物理 · 物理学 2018-05-15 Matthew L. Lister

We present the results of new radio observations carried out with the Karl G. Jansky Very Large Array C-configuration at 5.5 GHz for a sample of southern narrow-line Seyfert 1 galaxies (NLS1s). This work increases the number of known…

星系天体物理 · 物理学 2020-09-02 S. Chen , E. Jarvela , L. Crepaldi , M. Zhou , S. Ciroi , M. Berton , P. Kharb , L. Foschini , M. Gu , G. La Mura , A. Vietri

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

Narrow-line Seyfert 1 (NLS1) galaxies provide us with unique insights into the drivers of AGN activity under extreme conditions. Given their low black hole (BH) masses and near-Eddington accretion rates, they represent a class of galaxies…

高能天体物理现象 · 物理学 2017-06-28 V. Karamanavis , E. Angelakis , S. Komossa , I. Myserlis , D. Blinov , J. A. Zensus

Radio-loud Narrow-line Seyfert 1 (NLS1) galaxies are unique probes of the formation of powerful radio jets at extreme (near-Eddington) accretion rates and low black hole masses, in a regime very different from classical blazars and,…

星系天体物理 · 物理学 2018-08-07 S. Komossa

Flat-spectrum radio-loud Narrow-Line Seyfert 1 galaxies (NLS1s) are a recently discovered class of $\gamma$-ray emitting Active Galactic Nuclei (AGN), that exhibit some blazar-like properties which are explained with the presence of a…

The origin of the radio emission in active galactic nuclei (AGN) is still debated. Multiple physical mechanisms can contribute to the spectrum at these frequencies, including relativistic jets, the jet base, outflows, star formation, and…

Several narrow-line Seyfert 1 galaxies (NLS1s) have now been detected in gamma rays, providing firm evidence that at least some of this class of active galactic nuclei (AGN) produce relativistic jets. The presence of jets in NLS1s is…

Narrow-line Seyfert 1 (NLS1) galaxies are peculiar active galactic nuclei (AGN). Most of them do not show strong radio emission, but recently seven radio-quiet (or -silent) NLS1s have been detected flaring multiple times at 37 GHz by the…

星系天体物理 · 物理学 2020-04-22 M. Berton , E. Järvelä , L. Crepaldi , A. Lähteenmäki , M. Tornikoski , E. Congiu , P. Kharb , G. Terreran , A. Vietri

A fraction of Narrow Line Seyfert 1 galaxies (NLS1) are hosted by galaxies that present a disturbed morphology, in some cases hinting for merger processes, that are putative sources of gas replenishment. We have been investigating the…

星系天体物理 · 物理学 2018-09-06 Sonia Anton , Alessandro Caccianiga , Luca Bizzocchi , Jose Afonso
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