Radio-loud Narrow-Line Type 1 Quasars

By S. Komossa, Wolfgang Voges, Da-wei Xu, S. Mathur, H. Adorf, Gerard Lemson, Wolfgang J. Duschl, D. Grupe. 2006

251 citations recorded by the source corpus.

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 catalogs led to the identification of ∼11 radio-loud NLS1 candidates, including four previously known ones. This study almost triples the number of known radio-loud NLS1 galaxies if all candidates are confirmed. Most of the radio-loud NLS1 galaxies are compact, steep-spectrum sources accreting close to or above the Eddington limit. The radio-loud NLS1 galaxies of our sample are remarkable in that they occupy a previously rarely populated regime in NLS1 multiwavelength parameter space. While their [O III]/Hβ and Fe II/Hβ intensity ratios almost cover the whole range observed in NLS1 galaxies, their radio properties extend the range of radio-loud objects to those with small widths of the broad Balmer lines. Their black hole masses are generally at the upper observed end among NLS1 galaxies but are still unusually small in view of the radio loudness of the sources. Among the radio-detected NLS1 galaxies, the radio index R is distributed quite smoothly up to the critical value of R ≃ 10 and covers about 4 orders of magnitude in total. Statistics show that ∼7% of the NLS1 galaxies are formally radio-loud, while only 2.5% exceed a radio index R > 100. Implications for NLS1 models are discussed. Several mechanisms are considered as explanations for the radio loudness of the NLS1 galaxies and for the lower frequency of radio-loud galaxies among NLS1 galaxies than among quasars. While properties of most sources (with two to three exceptions) generally do not favor relativistic beaming, the combination of accretion mode and spin may explain the observations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/0099cd1f5a7374839b38bf9dca2998e26b243879

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. G. Ghisellini
2. Bing Zhang
3. F. Tavecchio
4. E. Orlando
5. Luigi Foschini
6. L. Maraschi
7. C. Dermer
8. S. Komossa

In Nuclear and High Energy Physics

1. G. Ghisellini
2. F. Tavecchio
3. Luigi Foschini
4. E. Orlando
5. L. Maraschi
6. C. Dermer
7. A. Reimer
8. Y. Kovalev

Citations in the corpus

• Properties of flat-spectrum radio-loud Narrow-Line Seyfert 1 Galaxies (2014, methodology): “The early surveys revealed only a handful of objects: 11 by Zhou & Wang (2002) and Komossa et al. (2006a), and 16 by Whalen et al. (2006).”
• Radio Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications (2006, background): “They are exceptionally radio-quiet as a class (Ulvestad et al. 1995; Greene et al. 2006), with only few reaching R > 100, and none producing a prominent extended radio structure (Zhou&Wang 2002;Whalen et al. 2006; Komossa et al. 2006).”
• On the Nature of Seyfert Galaxies with High [O III] λ5007 Blueshifts (2008, background): “On average, they tend to be less radio-loud than BLS1 galaxies (Zhou et al. 2006, Komossa et al. 2006) and share some similarities with compact steep spectrum radio sources (Komossa et al. 2006).”
• THE SIMULTANEOUS OPTICAL-TO-X-RAY SPECTRAL ENERGY DISTRIBUTION OF SOFT X-RAY SELECTED ACTIVE GALACTIC NUCLEI OBSERVED BY SWIFT (2010, background): “2–4258 is one of a few radio-loud NLS1s (Grupe et al. 2000; Komossa et al. 2006) and had shown one of the softest X-ray spectra of any AGN during the RASS.”
• FERMI/LARGE AREA TELESCOPE DISCOVERY OF GAMMA-RAY EMISSION FROM A RELATIVISTIC JET IN THE NARROW-LINE QUASAR PMN J0948+0022 (2009, background): “…Bank radio survey at 5 GHz (Bennett et al. 1986), this quasar is part of the sample drawn from the SDSS and FIRST (Faint Images of the Radio Sky at Twenty-Centimeters) in a systematic search for radio loud NLS1 objects (Zhou et al. 2003, Komossa et al. 2006, Zhou et al. 2006, Yuan et al. 2008).”
• RADIO-LOUD NARROW-LINE SEYFERT 1 AS A NEW CLASS OF GAMMA-RAY ACTIVE GALACTIC NUCLEI (2009, methodology): “According to Komossa et al. (2006), RL-NLS1s are more rare than quasars: 7% of NLS1s have RL > 10 and only 2.5% exceed RL = 50, while generally 10%–20% of quasars are radio loud.”