English
Related papers

Related papers: A statistical study of SDSS radio-emitters

200 papers

Building the radio sky template are crucial for detecting the 21 cm emission line signal from the Epoch of Reionization (EoR), as well as for other cosmological research endeavors. Utilizing data from the LOFAR Two-meter Sky Survey (LoTSS)…

Astrophysics of Galaxies · Physics 2024-11-07 Jinyang Lin , Zhenghao Zhu , Renyi Ma , Anna Bonaldi , Huanyuan Shan

We have collected emission line ([Oiii] 5007 and Halpha+[Nii]) and radio continuum images for a volume limited (cz <= 3600 km/s) sample of southern Seyfert galaxies. The optical data were obtained at ESO using the 2.2 m, NTT and 3.6 m…

Astrophysics · Physics 2007-05-23 Z. Tsvetanov , R. Morganti , R. A. E. Fosbury , M. G. Allen , J. Gallimore

Although studying outflows in the host galaxies of AGN have become the forefront of extra-galactic astronomy in recent years, estimating the energy associated with these outflows have been a major challenge. Determination of the energy…

This is the first paper in a series dedicated to the study of the emission-line and continuum properties of narrow line Seyfert 1 galaxies (NLS1s). We carried out a systematic search for NLS1s from objects assigned as ``QSOs'' or…

Astrophysics · Physics 2009-07-28 Hongyan Zhou , Tinggui Wang , Weimin Yuan , Honglin Lu , Xiaobo Dong , Junxian Wang , Youjun Lu

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 2007-05-23 Yuichi Terashima , Andrew S. Wilson

We study a complete and distance-limited sample of 25 LINERs, 21 of which have been imaged with the Hubble Space Telescope to study their physical properties and to compare their radio and optical properties with those of other samples of…

Astrophysics · Physics 2015-06-24 F. D. Macchetto , M. Chiaberge

We study the radio properties at 1.4 GHz of Seyfert galaxies with strong forbidden high-ionization lines (FHILs), selected from the Sloan Digital Sky Survey - a large-sized sample containing nearly equal proportion of diverse range of…

Astrophysics of Galaxies · Physics 2016-01-05 Dharam V. Lal

We aim to characterize the nature of galaxies whose optical emission line diagnostics are consistent with star formation, but whose X-ray properties strongly point towards the presence of an AGN. Understanding these sources is of particular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 N. Castelló-Mor , X. Barcons , L. Ballo , F. J. Carrera , M. J. Ward , C. Jin

We analyzed a large sample of SDSS spectra of Seyfert galaxies, subdividing Seyfert 1s based on their narrow-to-broad Halpha components. Comparing their narrow-lines (NL) to Seyfert2s in line-ratio diagrams, most of the NL of strong Sy 1.0…

Astrophysics of Galaxies · Physics 2026-01-13 Matthew Malkan , Lisbeth Jensen , Lei Hao

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…

High Energy Astrophysical Phenomena · Physics 2026-04-01 M. Berton , E. Järvelä , S. Chen , L. Crepaldi , I. Varglund , M. Coloma Puga , A. Jimenez-Gallardo , A. Lähteenmäki , S. Panda , C. Piscitelli , A. Tortosa

Discerning the exact nature of the sub-mJy radio population has been historically difficult due to the low luminosity of these sources at most wavelengths. Using deep ground based optical follow-up and observations from the Spitzer Space…

Astrophysics · Physics 2009-11-13 N. Seymour , T. Dwelly , D. Moss , I. McHardy , A. Zoghbi , G. Rieke , M. Page , A. Hopkins , N. Loaring

To get insight in the nature of the ionized gas in the nuclear region of LINERs we have performed a study of HST Halpha imaging of 32 LINERs. The main conclusion from this analysis is that for the large majority of LINERs (84%) an…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 J. Masegosa , I. Márquez , A. Ramirez , O. González-Martín

We study a complete and distance-limited sample of 25 LINERs, 21 of which have been imaged with the Hubble Space Telescope. In nine objects we detect an unresolved nucleus. In order to study their physical properties, we compare the radio…

Astrophysics · Physics 2009-11-10 Marco Chiaberge , Alessandro Capetti , F. Duccio Macchetto

The dominant fraction of the extragalactic $\gamma$-ray sources are blazars, active galactic nuclei with jets inclined at a small angle to the line of sight. Apart from blazars, a few dozen narrow-line Seyfert 1 galaxies (NLS1) and a number…

High Energy Astrophysical Phenomena · Physics 2025-03-06 K. É. Gabányi , S. Frey , K. Perger , E. Kun

This paper compares the optical spectra of a wide range of galaxies categorised as members of the Low Ionisation Nuclear Emission Region (LINER) class of active galactic nuclei (AGN). LINERs are defined by emission spectra with relatively…

Astrophysics of Galaxies · Physics 2014-09-11 Hartmut Winkler

Passive red galaxies frequently contain warm ionized gas and have spectra similar to low-ionization nuclear emission-line regions (LINERs). Here we investigate the nature of the ionizing sources powering this emission, by comparing nuclear…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Renbin Yan , Michael R. Blanton

We have examined ROSAT soft X-ray observations of a complete, distance-limited sample of Seyfert and LINER galaxies. X-ray data are available for 46 out of 60 such objects which lie within a hemisphere of radius 18 Mpc. We have constructed…

Astrophysics · Physics 2009-11-06 Eve L. Halderson , Edward C. Moran , Alexei V. Filippenko , Luis C. Ho

We present optical spectroscopic observations of 93 galaxies taken from the infra-red selected COLA (Compact Objects in Low Power AGN) sample. The sample spans the range of far-IR luminosities from normal galaxies to LIRGs. Of the galaxies…

The {\gamma}-ray detection from several radio-loud (RL) narrow-line Seyfert 1 (NLS1) galaxies has enabled us to study powerful relativistic jets in active galactic nuclei (AGNs) with smaller black hole masses and higher accretion rates than…

High Energy Astrophysical Phenomena · Physics 2018-07-27 Hui Yang , Weimin Yuan , Su Yao , Hai-Wu Pan , S. Komossa