The NATURE OF Γ-Ray LOUD NARROW-LINE SEYFERT I GALAXIES PKS 1502+036 AND PKS 2004–447

Paliya, Vaidehi S.; Stalin, C. S.; Shukla, Amit; Sahayanathan, S.

doi:10.1088/0004-637x/768/1/52

Cited by 45 publications

(65 citation statements)

References 85 publications

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“…the low-energy component is the tail of the synchrotron emission). This seems to be confirmed by the analysis and modelling of the SED (Abdo et al 2009c, Paliya et al 2013b; see also the Sect. 7).…”

Section: X-rayssupporting

confidence: 57%

Properties of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

Foschini

Berton

Caccianiga

et al. 2015

A&A

188

344

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We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources of this type and omitting those with steep radio spectra. We analyse data from radio frequencies to X-rays, and supplement these with information available from online catalogues and the literature in order to cover the full electromagnetic spectrum. This is the largest known multiwavelength survey for this type of source. We detected 90% of the sources in X-rays and found 17% at γ rays. Extreme variability at high energies was also found, down to timescales as short as hours. In some sources, dramatic spectral and flux changes suggest interplay between a relativistic jet and the accretion disk. The estimated masses of the central black holes are in the range ∼ 10 6−8 M ⊙ , lower than those of blazars, while the accretion luminosities span a range from ∼ 0.01 to ∼ 0.49 times the Eddington limit, with an outlier at 0.003, similar to those of quasars. The distribution of the calculated jet power spans a range from ∼ 10 42.6 to ∼ 10 45.6 erg s −1 , generally lower than quasars and BL Lac objects, but partially overlapping with the latter. Once normalised by the mass of the central black holes, the jet power of the three types of active galactic nuclei are consistent with each other, indicating that the jets are similar and the observational differences are due to scaling factors. Despite the observational differences, the central engine of RLNLS1s is apparently quite similar to that of blazars. The historical difficulties in finding radio-loud narrow-line Seyfert 1 galaxies might be due to their low power and to intermittent jet activity.

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Section: X-rayssupporting

confidence: 57%

Properties of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

Foschini

Berton

Caccianiga

et al. 2015

A&A

188

344

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“…Although massive black-hole-hosted blazars are known to be Compton dominated (e.g., Paliya et al 2016), our correlation analysis indicates that even blazars with low mass black holes can also have a large CD (> 1). The Fermi-LAT detected narrow line Seyfert 1 galaxies 11 are probably a good example of this (e.g., Paliya et al 2013). …”

Section: Black Hole Mass Dependencementioning

confidence: 95%

General Physical Properties of CGRaBS Blazars

Paliya

Marcotulli

Ajello

et al. 2017

ApJ

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We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 γ-ray detected (γ-ray loud) and 191 non γ-ray detected (γ-ray quiet) blazars, and we consider all the data up to 2016 April 1. We find that both the γ-ray loud and the γ-ray quiet blazar populations occupy similar regions in the WISE color-color diagram, and in the radio and X-ray bands γ-ray loud sources are brighter. A simple one-zone synchrotron inverse-Compton emission model is applied to derive the physical properties of both populations. We find that the central black hole mass and the accretion disk luminosity (L disk ) computed from the modeling of the optical-UV emission with a Shakura-Sunyaev disk reasonably matches with that estimated from the optical spectroscopic emission-line information. A significantly larger Doppler boosting in the γ-ray loud blazars is noted, and their jets are more radiatively efficient. On the other hand, the γ-ray quiet objects are more MeV-peaked, thus could be potential targets for next-generation MeV missions. Our results confirm the earlier findings about the accretion-jet connection in blazars; however, many of the γ-ray quiet blazars tend to deviate from the recent claim that the jet power exceeds L disk in blazars. A broadband study, considering a larger set of γ-ray quiet objects and also including BL Lacs, will be needed to confirm/reject this hypothesis and also to verify the evolution of the powerful high-redshift blazars into their low-power nearby counterparts.

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“…In addition, we used archival data from 2011, which were discussed by Paliya et al (2013). Details of each observation are listed in Table 1.…”

Section: Swift Observationsmentioning

confidence: 99%

“…Based on the empirical relation between BLR size and optical luminosity (Kaspi et al 2000), Osh01 estimated the black hole mass from the H β line to be 10 6.7 M , using high-resolution data from the Siding Spring 2.3 m Telescope. Studies in the X-rays (see e.g., G06; Paliya et al 2013) suggest an unobscured spectrum in the (0.3-10) keV band, a possible soft excess below 1 keV, and mild long-term flux variability.…”

Section: Introductionmentioning

confidence: 99%

The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004−447

Kreikenbohm

Schulz

Kadler

et al. 2015

A&A

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As part of the TANAMI multiwavelength progam, we discuss new X-ray observations of the γ-ray and radio-loud narrow line Seyfert 1 galaxy (γ-NLS1) PKS 2004−447. The active galaxy is a member of a small sample of radio-loud NLS1s detected in γ-rays by the Fermi Large Area Telescope. It stands out for being the radio-loudest and the only southern-hemisphere source in this sample. We present results from our X-ray monitoring program comprised of Swift snapshot observations from 2012 through 2014 and two new X-ray observations with XMM-Newton in 2012. Supplemented by archival data from 2004 and 2011, our data set allows for a careful analysis of the X-ray spectrum and variability of this peculiar source. The (0.5-10) keV spectrum is described well by a power law (Γ ∼ 1.6), which can be interpreted as non-thermal emission from a relativistic jet. The source exhibits moderate flux variability on timescales of both months and years. Correlated brightness variations in the (0.5-2) keV and (2-10) keV bands are explained by a single variable spectral component, such as the one from the jet. A possible soft excess seen in the data from 2004 cannot be confirmed by the new XMM-Newton observations taken during low-flux states. Any contribution to the total flux in 2004 is less than 20% of the power-law component. The (0.5-10) keV luminosities of PKS 2004−447 are in the range of (0.5−2.7) × 10 44 erg s −1 . A comparison of the X-ray properties among the known γ-NLS1 galaxies shows that in four out of five cases the X-ray spectrum is dominated by a flat power law without intrinsic absorption. These objects are moderately variable in their brightness, while spectral variability is observed in at least two sources. The major difference across the X-ray spectra of γ-NLS1s is the luminosity, which spans a range of almost two orders of magnitude from 10 44 erg s −1 to 10 46 erg s −1 in the (0.5-10) keV band.

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The NATURE OF Γ-Ray LOUD NARROW-LINE SEYFERT I GALAXIES PKS 1502+036 AND PKS 2004–447

Cited by 45 publications

References 85 publications

Properties of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

Properties of flat-spectrum radio-loud narrow-line Seyfert 1 galaxies

General Physical Properties of CGRaBS Blazars

The gamma-ray emitting radio-loud narrow-line Seyfert 1 galaxy PKS 2004−447

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