A comparative study of the physical properties for a representative sample of Narrow and Broad-line Seyfert galaxies

Jha, Vijay Kumar; Chand, Hum; Ojha, Vineet; Omar, Amitesh; Rastogi, Shantanu

doi:10.1093/mnras/stab3700

Cited by 3 publications

(4 citation statements)

References 85 publications

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“…The [O III λ5007] velocity shift and dispersion are found to be driven by the Eddington ratio, suggesting that the radiation pressure or wind from the accretion disc could drive these outflows to kpc-scales. Jha et al (2021) found strong blue asymmetry in the Hβ line, indicating strong outflows in NLS1s compared to the BLS1s, which are dominated by infall.…”

Section: Correlation Between Outflow Indicators and Photon Indexmentioning

confidence: 90%

“…8.3. Soft X-ray studies and kpc-scale outflow studies before eROSITA Jha et al (2021) presented a study of 144 NLS1s and 117 BLS1s based on ROSAT and XMM-Newton observations. For their NLS1 sample, the fraction of objects showing outflow signatures as negative AI was three times higher than for the BLS1 sample.…”

Section: Gas Outflows From Large Samples Based On [O III λ5007]mentioning

confidence: 99%

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The first look at narrow-line Seyfert 1 galaxies with eROSITA

Boller

Rakshit

et al. 2023

A&A

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We present the first look at the spectral and timing analysis of Narrow-Line Seyfert 1 Galaxies (NLS1s) with the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) on board the Spectrum-Roentgen-Gamma (SRG) mission. The sample of ∼1,200 NLS1s was obtained via cross-match of the first eROSITA All-Sky Survey (eRASS1) catalogue with the catalogue of spectroscopically selected NLS1s from the Sloan Digital Sky Survey (SDSS) DR12 by Rakshit et al. [ApJS, 229, 39 (2017)]. The X-ray spectral analysis is based on a simple power-law fit. The photon index distribution has a mean value of about 2.81±0.03, as expected from previous X-ray studies of NLS1s. Interestingly, it is positively skewed, and about 10 percent of the sources are located in the super-soft tail of photon indices larger than 4. These sources are of further interest as their source counts run into the X-ray background at values at around 1 keV. We argue that ionised outflows have been detected by eROSITA and may account for some of the extreme spectral steepness, which is supported by correlations found between the photon index and optical outflows parameters. We analysed the intrinsic X-ray variability of the eRASS1 to eRASS3 light curves of the sample but do not find significant variability neither during the individual survey scans nor between them.

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Section: Correlation Between Outflow Indicators and Photon Indexmentioning

confidence: 90%

Section: Gas Outflows From Large Samples Based On [O III λ5007]mentioning

confidence: 99%

The first look at narrow-line Seyfert 1 galaxies with eROSITA

Boller

Rakshit

et al. 2023

A&A

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“…Other optical characteristics such as flux ratio of [O I I I ] λ5007 /Hβ < 3, and strong permitted Fe emission lines are used in addition to the criterion of FWHM(Hβ) to characteristically define NLSy1 galaxies (Shuder & Osterbrock 1981). Besides, these galaxies also display peculiar characteristics in other wavelength, especially in X-ray wavelength, such as strong soft X-ray excess below 2 keV (e.g., Brandt et al 1997;Vaughan et al 1999;Vignali et al 2004;Ojha et al 2020b), steep soft X-ray spectra (e.g., Boller et al 1996;Wang et al 1996;Grupe et al 1998), rapid X-ray (sometimes optical) flux variability (e.g., Leighly 1999; Komossa E-mail: vineetojha@prl.res.in, vineetojhabhu@gmail.com & Meerschweinchen 2000;Miller et al 2000;Klimek et al 2004;Liu et al 2010;Paliya et al 2013a;Kshama et al 2017;Ojha et al 2019Ojha et al , 2020a, and blue-shifted emission line profiles (e.g., Zamanov et al 2002;Leighly & Moore 2004;Boroson 2005;Jha et al 2021). Furthermore, NLSy1s are believed to be relatively young AGNs, and they represent an early phase of their evolution (e.g., Mathur 2000;Sulentic et al 2000;Mathur et al 2001;Fraix-Burnet et al 2017;Komossa 2018;Paliya 2019).…”

Section: Introductionmentioning

confidence: 99%

“…Nonetheless, despite a blazar-like double-humped spectral energy distribution (SED) of a few RLNLSy1s (e.g., Abdo et al 2009c;Paliya et al 2013b;Paliya 2019), a minuscule fraction of RLNLSy1s, especially very radio-loud (R > 100) RLNLSy1s exhibit interesting multi-wavelength characteristics such as compact radio cores, high brightness temperature, superluminal motion, flat radio and X-ray spectra, and rapid infrared and X-ray flux variability similar to blazar class of AGN (Boller et al 1996;Grupe et al 1998;Leighly 1999;Hayashida 2000;Komossa & Meerschweinchen 2000;Yuan et al 2008;Jiang et al 2012;Orienti et al 2012;Itoh et al 2013;Yao et al 2015;Berton et al 2018;Gabanyi et al 2018;Lister 2018). All these characteristics give indirect evidence of the presence of jets in them.…”

Section: Introductionmentioning

confidence: 99%

Evidence of jet-induced optical microvariability in radio-loud narrow-line Seyfert 1 galaxies

Ojha

Jha

Chand

et al. 2022

Monthly Notices of the Royal Astronomical Society

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To quantify the role of radio jets for Intra-Night Optical Variability (INOV) in Radio-Loud Narrow-Line Seyfert 1 (RLNLSy1) galaxies, we report the first systematic comparative INOV study of 23 RLNLSy1 galaxies, with 15 RLNLSy1s having confirmed detection of jets (jetted) and the remaining 8 RLNLSy1s having no detection of jets (non-jetted) based on their Very Long Baseline Array observations. We have monitored these two samples, respectively, in 37 and 16 sessions of a minimum 3-hour duration each. Based upon Fη-test at 99% confidence level with a typical INOV amplitude (ψ) detection threshold of > 3%, we find the INOV duty cycles of 12% for the sample of jetted RLNLSy1s, however, none of the sources showed INOV in the sample of non-jetted RLNLSy1s. Among the jetted RLNLSy1s, we find that the Duty Cycle (DC) for jetted γ-ray detected (γ-ray) RLNLSy1s is found to be 34% in contrast to null INOV detection in the case of non-γ-ray RLNLSy1s. It suggests that instead of the mere presence of a jet, relativistic beaming plays a significant role for INOV in the case of low-luminous high accreting AGNs such as NLSy1s in which dilution of the AGN’s non-thermal optical emission by the (much steadier) optical emission contributed by the nuclear accretion disc is quite likely. Our study of jetted γ-ray RLNLSy1s shows more frequent INOV detection for sources with higher apparent jet speed. Further, our results also suggest that among the NLSy1s, only jetted γ-ray RNLSy1 galaxies DC approaches blazar like DC.

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Study of the optical to X-ray broad emission lines of Mrk 110

Juráňová,

Costantini,

Di Gesu

et al. 2024

A&A

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Aims. In order to shed light on the characteristics of the broad line region (BLR) in a narrow-line Seyfert 1 galaxy, we present an analysis of X-ray, UV, and optical spectroscopic observations of the broad emission lines in Mrk 110. Methods. For the broad-band modelling of the emission-line luminosity, we adopt the “locally optimally emitting cloud” approach, which allows us to place constraints on the gas radial and density distribution. By exploring additional environmental effects, we investigate the possible scenarios resulting in the observed spectra. Results. We find that the photoionised gas in Mrk 110 responsible for the UV emission can fully account for the observed low-ionisation X-ray lines. The overall ionisation of the gas is lower, and one radial power-law distribution with a high integrated covering fraction Cf ≈ 0.5 provides an acceptable description of the emission lines spanning from X-rays to the optical band. The BLR is likely more compact than the broad-line Seyfert 1s studied so far, extending from ∼1016 to ∼1018 cm, and limited by the dust sublimation radius at the outer edge. Despite the large colour excess predicted by the Balmer ratio, the best fit suggests E(B − V)≈0.03 for both the ionising luminosity and the BLR, indicating that extinction might be uniform over a range of viewing angles. While the adopted data-modelling technique does not allow us to place constraints on the geometry of the BLR, we show that the addition of models with a clumpy, equatorial, wind-like structure may lead to a better description of the observed spectra.

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A comparative study of the physical properties for a representative sample of Narrow and Broad-line Seyfert galaxies

Cited by 3 publications

References 85 publications

The first look at narrow-line Seyfert 1 galaxies with eROSITA

The first look at narrow-line Seyfert 1 galaxies with eROSITA

Evidence of jet-induced optical microvariability in radio-loud narrow-line Seyfert 1 galaxies

Study of the optical to X-ray broad emission lines of Mrk 110

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