Absorbed relativistic jets in radio-quiet narrow-line Seyfert 1 galaxies

Berton, M.; Järvelä, E.; Crepaldi, Luca; Lähteenmäki, A.; Tornikoski, M.; Congiu, Enrico; Kharb, P.; Terreran, G.; Vietri, A.

doi:10.1051/0004-6361/202037793

Cited by 31 publications

(54 citation statements)

References 90 publications

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“…1 The radio-loud (RL) fraction of NLS1s is very small, only ∼7 per cent with R > 10 and ∼2.5 per cent with R > 100 (Komossa et al 2006), compared with that of BLS1s and quasars about ∼10-15 per cent (Ivezić et al 2002). However, the definition of radio loudness could be misleading, especially for NLS1s (Foschini 2011b;Berton et al 2020b). For instance, star formation can produce strong radio emission at low frequencies in late-type galaxies.…”

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confidence: 99%

Radio morphology of southern narrow-line Seyfert 1 galaxies with Very Large Array observations

Chen

Järvelä

Crepaldi

et al. 2020

Monthly Notices of the Royal Astronomical Society

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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 radio-detected NLS1s in the southern hemisphere, and confirms that the radio emission of NLS1s is mainly concentrated in a central region at kpc-scale and only a few sources show diffuse emission. In radio-quiet NLS1s, the radio luminosity tends to be higher in steep-spectrum sources and be lower in flat-spectrum sources, which is opposite to radio-loud NLS1s. This may be because the radio emission of steep NLS1s is dominated by misaligned jets, AGN-driven outflows, or star formation superposing on a compact core. Instead the radio emission of flat NLS1s may be produced by a central core which has not yet developed radio jets and outflows. We discover new NLS1s harboring kpc-scale radio jets and confirm that a powerful jet does not require a large-mass black hole to be generated. We also find sources dominated by star formation. These NLS1s could be new candidates in investigating the radio emission of different mechanisms.

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confidence: 99%

Radio morphology of southern narrow-line Seyfert 1 galaxies with Very Large Array observations

Chen

Järvelä

Crepaldi

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…These peculiar objects show mJy-level or lower flux density at 5 GHz, but they were observed flaring at Jy-level at 37 GHz, indicating that they harbor relativistic jets [57]. The reason for the weak radio emission at low frequencies may be a form of absorption, either free-free or synchrotron self-absorption [58].…”

Section: Sample Selection and Data Analysismentioning

confidence: 95%

“…The bolometric luminosity was estimated using its scaling relation with the Hβ luminosity, as in [66]. The radio luminosities are derived from B18 and [58]. The radio loudness parameter is defined as the ratio between the radio flux density at 5 GHz and the flux density in the optical B band.…”

Section: Short Namementioning

confidence: 99%

Jet-Induced Feedback in the [O III] Lines of Early Evolution Stage Active Galactic Nuclei

Berton

Järvelä

2021

Universe

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It is well known that active galactic nuclei (AGN) show various forms of interaction with their host galaxy, in a number of phenomena generally called AGN feedback. In particular, the relativistic plasma jets launched by a fraction of AGN can strongly affect their environment. We present here a study of the [O III] λλ4959,5007 lines in a diverse sample of early evolution stage AGN–specifically narrow-line Seyfert 1 galaxies. Radio imaging observations of all of the sources enable a division to jetted and non-jetted sources, and exploiting this we show that the ionized gas properties are significantly influenced by the presence of the jets, as we often find the [O III] lines (blue-)shifted with respect to their restframe wavelength. We also show how the radio morphology and the radio spectral index do not seem to play a role in the origin of the [O III] shifts, thus suggesting that the source inclination is not relevant to the lines displacement. We do not find a strong relation between the [O III] line properties and the bolometric luminosity, suggesting that within our sample radiatively driven outflows do not seem to have a significant contribution to the [O III] line kinematics. We finally suggest that [O III] shifts may be a good proxy to identify the presence of relativistic jets. Additional studies, especially with integral-field spectroscopy, will provide a deeper insight into the relation between jets and their environment in early evolution stage AGN.

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“…For the point spread function (PSF) modelling we observed a bright nearby star for each source. The data was reduced using the NOTCam data reduction package 3 for IRAF 4 and following the standard procedure.…”

Section: Sample Observations and Image Analysismentioning

confidence: 99%

“…However, it has been proposed that the virial method widely used to estimate the black hole masses underestimates them in NLS1 galaxies due to orientation effects caused by flattened broad-line region and NLS1 sources preferentially seen face-on [11,37]. Some alternative methods to estimate the black hole mass support this scenario [38,5,3,9], whereas others favour low black hole masses [36,14,44,4].…”

Section: Introductionmentioning

confidence: 99%