A spectrophotometric atlas of Narrow-Line Seyfert 1 galaxies

Véron-Cetty, M. P.; Véron, Philippe; Gonçalves, A. C.

doi:10.1051/0004-6361:20010489

Cited by 281 publications

(356 citation statements)

References 204 publications

(403 reference statements)

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“…The Heckman et al 1981;Véron-Cetty et al 2001) and were interpreted as an indication for high ionisation outflows from the nucleus (Zamanov & Marziani 2002). We can not spatially resolve the extended ionised gas closer than ∼1 kpc from the nucleus, but outside this unresolved region we did not find any signatures for a similarly broad and blueshifted ionised gas component indicating that this possibly outflowing component is restricted to scales below ∼1 kpc.…”

Section: The Origin Of the Gasmentioning

confidence: 68%

Mapping the ionised gas around the luminous QSO HE 1029-1401: evidence for minor merger events?

Sánchez

Wisotzki²,

Jahnke

et al. 2010

A&A

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We present VIMOS integral field spectroscopy of the brightest radio-quiet QSO on the southern sky HE 1029-1401 at a redshift of z = 0.086. Standard decomposition techniques for broad-band imaging are extended to integral field data in order to deblend the QSO and host emission. We perform a tentative analysis of the stellar continuum, finding a young stellar population (<100 Myr) or a featureless continuum embedded in an old stellar population (10 Gyr) typical for a massive elliptical galaxy. The stellar velocity dispersion of σ * = 320 ± 90 km s −1 and the estimated black hole mass log(M BH /M ) = 8.7 ± 0.3 are consistent with the local M BH -σ * relation within the errors. For the first time, we map the two-dimensional ionised gas distribution and the gas velocity field around HE 1029-1401. While the stellar host morphology is purely elliptical, we find a highly structured distribution of ionised gas out to 16 kpc from the QSO. The gas is highly ionised solely by the QSO radiation and has a significantly lower metallicity than would be expected for the stellar mass of the host, indicating an external origin of the gas most likely due to minor mergers. We find a rotating gas disc around the QSO and a dispersion-dominated non-rotating gas component within the central 3 kpc. At larger distances the velocity field is heavily disturbed, which could be interpreted as another signature of past minor merger events. Alternatively, the arc-like structure seen in the ionised gas might also be indicative of a large-scale expanding bubble, centred on and possibly driven by the active nucleus.

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Section: The Origin Of the Gasmentioning

confidence: 68%

Mapping the ionised gas around the luminous QSO HE 1029-1401: evidence for minor merger events?

Sánchez

Wisotzki²,

Jahnke

et al. 2010

A&A

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“…While these results strongly suggest that the [O III] emission is not unusual in NLSy1s (see, also, Veron-Cetty et al 2001), perhaps other lines can be used to constrain the EUV continuum and, ultimately, the structure of the central engine. In fact, Veron-Cetty et al (2001) suggest that it might be more advantageous to classify Seyferts based on the Fe II emission. Clearly, more data are needed to probe the nature of the NLSy1 phenomenon.…”

Section: Discussionmentioning

confidence: 99%

On the Relationship between the Optical Emission‐Line and X‐Ray Luminosities in Seyfert 1 Galaxies

Kraemer

George

Crenshaw

et al. 2004

ApJ

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We have explored the relationship between the [O III] λ5007 and the 2-10 keV luminosities for a sample of Broad-and Narrow-Line Seyfert 1 galaxies (BLSy1 and NLSy1, respectively). We find that both types of Seyferts span the same range in luminosity and possess similar [O III]/X-ray ratios. The NLSy1s are more luminous than BLSy1s, when normalized to their central black hole masses, which is attributed to higher mass accretion rates. However, we find no evidence for elevated [O III]/X-ray ratios in NLSy1s, which would have been expected if they had excess EUV continuum emission compared to BLSy1s. Also, other studies suggest that the gas in narrow-line regions (NLR) of NLSy1s and NLSy1s span a similar range in ionization, contrary to what is expected if those of the former are exposed to a stronger flux of EUV radiation. The simplest interpretation is that, like BLSy1s, a large EUV bump is not present in NLSy1s. However, we show that the [OIII]/X-ray ratio can be lowered as a result of absorption of the ionizing continuum by gas close to the central source, although there is no evidence that intrinsic line-of-sight absorption is more common among NLSy1s, as would be expected if there were a larger amount of circumnuclear gas. Other possible explanations include: 1) anisotropic emission of the ionizing radiation, 2) higher gas densities in the NLR of NLSy1s, resulting in lower average

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“…While Seyfert 2's are active galaxies with narrow emission-line optical spectra, NLS1s have the broad emissionline optical spectra of type 1 Seyfert galaxies, but with the Table 1 is only available in electronic form at http://www.aanda.org narrowest Balmer lines from the broad line region and the strongest Fe II emission (e.g., Osterbrock 1989;Véron-Cetty et al 2001). Extreme properties are also observed in X-rays, such as a strong soft excess emission below 1 keV and rapid flux variability, accompanied by steeper photon indices with respect to (w.r.t.)…”

Section: Introductionmentioning

confidence: 99%

Narrow-line Seyfert 1 galaxies: an amasing class of AGN

Tarchi

Castangia

Columbano

et al. 2011

A&A

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Context. Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that have all the properties of type 1 Seyfert galaxies but show peculiar characteristics, including the narrowest Balmer lines, strongest Fe II emission, and extreme properties in the X-rays. Line and continuum radio observations provide an optimal tool to access the (often) optically obscured innermost regions of AGN and reveal the kinematics of the gas around their central engines. Aims. We investigate the interplay between the peculiar NLS1 class of AGN and the maser phenomenon, to help us understand the nature of the maser emission in some NLS1s where water maser emission has been detected. Methods. We observed a sample of NLS1 galaxies with the Green Bank Telescope in a search for water maser emission at 22 GHz. We also reduced and analysed archival Green Bank Telescope and Very Large Array data and produced 22-GHz spectra for the five NLS1 galaxies with detected maser emission. In particular, we imaged the maser and nuclear radio continuum of NGC 5506 at subarcsec scales with the Very Large Array. Results. We discovered maser emission in two NLS1 galaxies: IGR J16385-2057, and IRAS 03450+0055. In addition to the three previously known maser detections in the NLS1s Mrk 766, NGC 4051, and NGC 5506, this yields a water maser detection rate in NLS1 galaxies of ∼7% (5/71). This value rises significantly to ∼21% (5/24) when considering only NLS1 galaxies at recessional velocities less than 10 000 km s −1 . For NGC 4051 and NGC 5506, we find that the water maser emission is located within 5 and 12 pc, respectively, of nuclear radio continuum knots, which are interpreted as core-jet structures. Conclusions. The water maser detection rate in NLS1s is surprisingly high, much higher than the detection rate obtained for type 1 AGN and similar to those in Seyfert 2 and low-ionization nuclear emission-line region galaxies. The masers in NGC 4051 and NGC 5506 are nuclear and associated with the AGN, either with an accretion disk, a radio jet, or a nuclear outflow. The apparent lack of high-velocity maser features and evidence, recently reported, of radiative outflows and radio jets in the host galaxies seems to favour interpretation as a jet or an outflow. A similar association is also seemingly true for the maser in Mrk 766, IGR J16385-2057, and IRAS 03450+0055, although, in these cases, without radio interferometric measurements we cannot rule out an off-nuclear origin of the emission.

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A spectrophotometric atlas of Narrow-Line Seyfert 1 galaxies

Cited by 281 publications

References 204 publications

Mapping the ionised gas around the luminous QSO HE 1029-1401: evidence for minor merger events?

Mapping the ionised gas around the luminous QSO HE 1029-1401: evidence for minor merger events?

On the Relationship between the Optical Emission‐Line and X‐Ray Luminosities in Seyfert 1 Galaxies

Narrow-line Seyfert 1 galaxies: an amasing class of AGN

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