Narrow-line Seyfert 1 Research Articles

Exploring the nature of the jetted hybrid AGNs: PKS 2004-447, 3C 286, and PKS 0440-00 through the SED modeling

ABSTRACT In this work, we explore the connection of three jetted $\gamma -$loud AGNs classes: Compact steep-spectrum sources (CSS), Narrow-line Seyfert 1 (NLS1), and flat-spectrum radio quasars, through the modelling of the spectral energy distribution (SED). We selected two sources identified as CSS/NLS1 hybrids, PKS 2004-440 and 3C 286. Additionally, we included the source PKS 0440-00, initially classified as an FSRQ in the first Fermi-LAT catalogue, but recently reclassified as an NLS1. We present the results of their broadband SED modelling using a one-zone leptonic synchrotron-self Compton (SSC) + external Compton (EC) model. By exploring the parameter space and investigating the disc–jet connection in these sources, we analyse their classification in a model-dependent way. Our findings reveal that modeling PKS 2004-447 at relatively large angles, as expected for CSS, results in an SSC-dominated inverse Compton emission. In contrast, at low-observing angles, the inverse Compton emission is dominated by external photon fields. Both scenarios result in a jet with a low-radiative power. For 3C 286, we found that using a one-zone model limits the jet viewing angle to $\sim 7^{\circ }$, mainly due to its impact on the $\gamma$-ray emission. Our model results show a magnetically dominated jet, consistent with $\gamma$-CSS sources. Our results suggest that PKS 0440-00, can be classified as a powerful $\gamma -$NLS1, characterized by high accretion power and a jet dominated by bulk motion, similar to FSRQs.

Unprecedented extreme high-frequency radio variability in early-stage active galactic nuclei

ABSTRACT We report on the discovery of one of the most extreme cases of high-frequency radio variability ever measured in active galactic nuclei (AGNs), observed on time-scales of days and exhibiting variability amplitudes of 3–4 orders of magnitude. These sources, all radio-weak narrow-line Seyfert 1 (NLS1) galaxies, were discovered some years ago at Aalto University Metsähovi Radio Observatory (MRO) based on recurring flaring at 37 GHz, strongly indicating the presence of relativistic jets. In subsequent observations with the Karl G. Jansky Very Large Array (JVLA) at 1.6, 5.2, and 9.0 GHz no signs of jets were seen. To determine the cause of their extraordinary behaviour, we observed them with the JVLA at 10, 15, 22, 33, and 45 GHz, and with the Very Long Baseline Array (VLBA) at 15 GHz. These observations were complemented with single-dish monitoring at 37 GHz at MRO, and at 15 GHz at Owens Valley Radio Observatory (OVRO). Intriguingly, all but one source either have a steep radio spectrum up to 45 GHz, or were not detected at all. Based on the 37 GHz data, the time-scales of the radio flares are a few days, and the derived variability brightness temperatures and variability Doppler factors are comparable to those seen in blazars. We discuss alternative explanations for their extreme behaviour, but so far no definite conclusions can be made. These sources exhibit radio variability at a level rarely, if ever, seen in AGN. They might represent a new type of jetted AGN, or a new variability phenomenon, and thus deserve our continued attention.

On the Nature of the Radio Calibrator and Gamma-Ray Emitting NLS1 Galaxy 3C 286 and Its Multiwavelength Variability

The quasar 3C 286, a well-known calibrator source in radio astronomy, was found to exhibit exceptional multiwavelength properties. Its rich and complex optical emission-line spectrum revealed its narrow-line Seyfert 1 (NLS1) nature. Given its strong radio emission, this makes 3C 286 one of the radio-loudest NLS1 galaxies known to date. 3C 286 is also one of very few known compact steep-spectrum (CSS) sources detected in the gamma-ray regime. Observations in the X-ray regime, rarely carried out so far, revealed evidence for variability, raising the question whether it is driven by the accretion disk or jet. 3C 286 is also well known for its damped Lyman alpha system from an intervening absorber at z = 0.692, triggering a search for the corresponding X-ray absorption along the line-of-sight. Here, we present new observations in the radio, X-ray, optical, and UV bands. The nature of the X-ray variability is addressed. Spectral evidence suggests that it is primarily driven by the accretion disk (not the jet), and the X-ray spectrum is well fit by a powerlaw plus soft excess model. The radio flux density and polarization remain constant at the Effelsberg telescope resolution, reconfirming the use of 3C 286 as radio calibrator. The amount of reddening/absorption along the line-of-sight intrinsic to 3C 286 is rigorously assessed. None is found, validating the derivation of a high Eddington ratio (L/LEdd ∼ 1) and of the very high radio-loudness index of 3C 286. Based on the first deep Chandra image of 3C 286, tentative evidence for hard X-ray emission from the SW radio lobe is reported. A large variety of models for the gamma-ray emission of 3C 286 are briefly discussed.

A comparative analysis of the active galactic nucleus and star formation characteristics of broad- and narrow-line Seyfert 1 galaxies

We report here our comparative analysis of the active galactic nucleus (AGN) and star formation (SF) characteristics of a sample of narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) galaxies. Our sample consisted of 373 BLS1 and 240 NLS1 galaxies and spanned the redshift 0.02 $<$ $z$ $<$ 0.8. The broad-band spectral energy distribution, constructed using data from the ultra-violet to the far-infrared, was modelled using CIGALE to derive the basic properties of our sample. We searched for differences in stellar mass (M$_ ast $), star formation rate (SFR), and AGN luminosity (L$_ AGN $) in the two populations. We also estimated new radiation-pressure-corrected black hole masses for our sample of BLS1 and NLS1 galaxies. While the virial black hole mass (M$_ BH $) of BLS1 galaxies is similar to their radiation-pressure-corrected M$_ BH $ values, the virial M$_ BH $ values of NLS1 galaxies are underestimated. We found that NLS1 galaxies have a lower M$_ BH $ of log (M$_ BH M$_ odot ) = 7.45 pm 0.27 and a higher Eddington ratio of log ($ Edd $) = $-$0.72 pm 0.22 than BLS1 galaxies, which have log (M$_ BH M$_ odot ) and $ Edd $ values of 8.04 pm 0.26 and $-$1.08 pm 0.24, respectively. The distributions of M$_ ast $, SFR, and specific star formation (sSFR = SFR/M$_ ast $) for the two populations are indistinguishable. This analysis is based on an independent approach and contradicts reports in the literature that NLS1 galaxies have a higher SF than BLS1 galaxies. While we found that L$_ AGN $ increases with M$_ ast $, L$_ SF $ flattens at high M$_ ast $ for both BLS1 and NLS1 galaxies. The reason may be that SF is suppressed by AGN feedback at M$_ ast $ higher than sim 1011 M$_ odot $ or that the AGN fuelling mechanism is decoupled from SF. Separating the sample into radio-detected and radio-undetected subsamples, we found no difference in their SF properties suggesting that the effect of AGN jets on SF is negligible.

Classification Of Flat Spectrum Radio Quasars By Optical Activity Types

We have carried out a spectral classification by the activity types for a subsample of blazars from the BZCAT v.5 Catalogue, namely the Flat Spectrum Radio Quasars (FSRQ) candidates, designated in the catalogue as BZQ subtype objects. The classification is based on the Sloan Digital Sky Survey (SDSS) homogeneous medium-resolution optical spectroscopy and along with the standard BPT-type diagnostic diagrams, we have applied our newly introduced fine classification scheme with subtypes of quasars and considering many more features. Out of 1909 BZQ objects, 618 having SDSS spectra were classified, resulting in 445 broad-line QSOs, 19 narrow-line QSOs, 138 broad-line Seyferts, 8 narrow-line Seyferts, and 2 Emission-line galaxies without a proper classification. We have calculated the absolute magnitudes and luminosities for all objects to distinguish QSOs from Seyferts, as defined by the Catalogue of QSOs and Active Galaxies, -22m.25 separation limit. This way 148 objects changed their BZCAT subtypes between BZQ to BZG, and also 6 BZQ objects to BZU.

Superluminal Motion and Jet Parameters in the Gamma-ray-Emitting Narrow-Line Seyfert 1 Galaxy TXS 1206+549

Narrow-line Seyfert 1 (NLS1) galaxies are a peculiar subclass of active galactic nuclei (AGN). Among them, TXS 1206+549 belongs to a small group of radio-loud and γ-ray-emitting NLS1 galaxies. We focus on the radio properties of this galaxy by analysing archival, high-resolution, very long baseline interferometry (VLBI) imaging observations taken at 8 GHz frequency in six epochs between 1994 and 2018. Using the milliarcsecond-scale radio structure, we can resolve a core and a jet component whose angular separation increases by (0.055±0.006) mas yr−1. This corresponds to an apparent superluminal jet component motion of (3.5±0.4)c. From the core brightness temperature and the jet component proper motion, we determine the characteristic Doppler-boosting factor, the bulk Lorentz factor, and the jet viewing angle. We find no compelling evidence for a very closely aligned blazar-type jet. The parameters for TXS 1206+549 resemble those of radio-loud quasar jets with a moderate Lorentz factor (Γ≈4) and ϑ≈24∘ inclination to the line of sight.

Homogeneous fine classification of Markarian galaxies based on SDSS medium-resolution spectroscopy

Context. Markarian (Mrk) galaxies, revealed due to their ultraviolet excess are very famous; they play a significant role in many astro-physical problems and come in a variety of types: Seyferts (Sys), low-ionization narrow emission-line regions (LINERs), starbursts (SBs), blue compact dwarf galaxies (BCDGs), as well as some quasars (QSOs) and blazars. They also appear as sources of non-optical radiation, such as gamma-ray, X-ray, ultraviolet (UV), infrared (IR), and radio, including some extremely high-energy gamma-ray sources (Mrk 421, Mrk 501) and very high-luminosity IR galaxies (Mrk 231). Aims. The classifications of Mrk galaxies for activity types have been carried out based on old mostly poor-quality and inhomoge-neous spectra (relatively low-resolution photographic spectra and low S/N spectra). The Sloan Digital Sky Surveys (SDSS) provides ~90% of the existing medium-resolution spectra, and is a relevant homogeneous database for classification of galaxies. Our aim was to obtain homogeneous classifications of Mrk galaxies by means of the SDSS spectra. Methods. Based on our work on the classification of newly revealed objects from various recent catalogs, we developed a fine classification scheme for activity types based on the homogeneous database of the SDSS spectroscopy. This scheme was applied to Mrk galaxies having spectra in the SDSS (779 out of 1544, 50.45%). Results. As a result, 779 Mrk galaxies now have homogeneous optical spectral classification that can be used for further studies and statistics of their physical and spatial properties. We revealed 2 QSOs, 49 classical Seyferts (broad-line Seyferts 1, BLS1s), 17 narrow-line Seyferts 1 (NLS1s), 4 Sy2s, 12 LINERs, 11 active galactic nuclei (AGN) without a definite type, 31 Composite spectrum objects, and 533 HII/Starbursts. Due to low-quality spectra, some objects were left without definite activity types and were classified as emission or absorption galaxies.

Changing-Look Narrow-Line Seyfert 1 Galaxies, their Detection with SVOM, and the Case of NGC 1566

We discuss applications of the study of the new and barely explored class of changing-look (CL) narrow-line Seyfert 1 (NLS1) galaxies and comment on their detection with the space mission SVOM (Space Variable Objects Monitor). We highlight the case of NGC 1566, which is outstanding in many respects, for instance as one of the nearest known CL AGN undergoing exceptional outbursts. Its NLS1 nature is discussed, and we take it as a nearby prototype for systems that could be discovered and studied in the near future, including with SVOM. Finally, we briefly examine the broader implications and applications of CL events in NLS1 galaxies and show that such systems, once discovered in larger numbers, will greatly advance our understanding of the physics of the environment of rapidly growing supermassive black holes. This White Paper is part of a sequence of publications which explore aspects of our understanding of (CL) NLS1 galaxy physics with future missions.

Spectropolarimetry and spectral decomposition of high-accreting narrow-line Seyfert 1 galaxies

Context. Narrow-line Seyfert 1 (NLSy1) galaxies have been shown to have high Eddington ratios and relatively small black hole mass. The measurement of these black hole masses is based on the virial relation that is dependent on the distribution of the line-emitting gas and the viewing angle to the source. Spectropolarimetry enables us to probe the geometry of this line-emitting gas and independently estimate the viewing angle of the source by comparing the spectrum viewed under natural light and polarized light. Aims. We aim to (i) estimate the virial factor using the viewing angles inferred from spectropolarimetric measurements for a sample of NLSy1s which influences the measurement of the black hole masses; (ii) model the natural and polarized spectra around the Hα region using spectral decomposition and spectral fitting techniques; (iii) infer the physical conditions (e.g., density and optical depth) of the broad-line region and the scattering medium responsible for the polarization of the Hα emission line (and continuum); and (iv) model the Stokes parameters using the polarization radiative transfer code STOKES. Methods. Using the FORS2 instrument at the European Southern Observatory’s (ESO) Very Large Telescope, We performed spectropolarimetric observations of three NLSy1: Mrk 1044, SDSS J080101.41+184840.7, and IRAS 04416+1215. We used the ESO REFLEX workflow to perform a standard data reduction and extract the natural and polarized spectra. We then modeled the Hα region in the reduced spectra using IRAF spectral fitting procedures and estimated the Stokes parameters and the viewing angles of the three sources. We modeled the Stokes parameters, inferred the properties of the scattering media located in the equatorial and polar regions, and simulated the spectra observed both in natural light and in polarized light using the polarization radiative transfer code STOKES. Results. The viewing angles recovered for the three sources indicate that they occupy separate locations in the viewing angle plane, from an almost face-on (IRAS 04416+1215) to an intermediate (SDSS J080101.41+184840.7), to a highly inclined (Mrk 1044) orientation. Nevertheless, we confirm that all three sources are high Eddington ratio objects. We were successful in recovering the observed Hα line profile in both the natural and polarized light using the STOKES modeling. We recovered the polarization fractions of the order of 0.2−0.5% for the three sources although the recovery of the phase angle is sub-optimal, mainly due to the noise in the observed data. Our principal component analysis shows that the sample of 25 sources, collected from the literature and including our sources, are mainly driven by the black hole mass and Eddington ratio. We reaffirm the connection of the strength of the optical FeII emission with the Eddington ratio, but the dependence on the viewing angle is moderate and resembles more of a secondary effect.

Origin of the complex iron line structure and spectral variation in Mrk 766

ABSTRACT Complex Fe-K emission/absorption line features are commonly observed in the 6–11 keV band from Active Galactic Nuclei (AGN). These features are formed in various physical components surrounding the black holes. The Narrow-Line Seyfert 1 (NLS1) galaxy Mrk 766, in particular, exhibits characteristic blue-shifted Fe-K absorption lines caused by the ultrafast outflow (UFO), and a broad Fe-K emission line, as well as variable absorbers partially covering the X-ray emitting region. We re-analyse the Mrk 766 archival data of XMM-Newton, NuSTAR, and Swift to investigate the origin of the Fe-K line feature and the 0.3–79 keV energy spectral variation. We have found that the spectral variation in ≲10 keV is primarily explained by the variable partial covering of the central X-ray source by multilayer absorbing clouds. The Fe-K line feature consists of the blue-shifted absorption lines due to the UFO, a narrow emission line from the distant material, a broad emission line from the inner-disc reflection, and a slightly broadened weak emission line at around 6.4–6.7 keV whose equivalent width is ∼0.05 keV. The last one is presumably due to the resonance scattering in the UFO out of the line-of-sight, as predicted by a Monte Carlo simulation based on the hydrodynamical UFO modelling. We suggest that the seemingly complex Fe-K line features and the X-ray energy spectra of Mrk 766 are explained by a moderately extended central X-ray source around a Schwarzschild black hole, an optically thick accretion disc with a truncated inner-radius, the UFO, multilayer partial covering clouds, and a torus.

Investigating the Origin of the Absorption-line Variability in the Narrow-line Seyfert 1 Galaxy WPVS 007

Broad absorption line quasars are actively accreting supermassive black holes that have strong outflows characterized by broad absorption lines in their rest-UV spectra. Variability in these absorption lines occurs over months to years depending on the source. WPVS 007, a low-redshift, low-luminosity narrow-line Seyfert 1 (NLS1) shows strong variability over shorter timescales, providing a unique opportunity to study the driving mechanism behind this variability that may mimic longer-scale variability in much more massive quasars. We present the first variability study using the spectral synthesis code SimBAL, which provides velocity-resolved changes in physical conditions of the gas using constraints from multiple absorption lines. Overall, we find WPVS 007 to have a highly ionized outflow with a large mass-loss rate and kinetic luminosity. We determine the primary cause of the absorption-line variability in WPVS 007 to be a change in covering fraction of the continuum by the outflow. This study is the first SimBAL analysis where multiple epochs of observation were fit simultaneously, demonstrating the ability of SimBAL to use the time domain as an additional constraint in spectral models.

Constraints on the ultrafast outflows in the narrow-line Seyfert 1 galaxy Mrk 1044 from high-resolution time- and flux-resolved spectroscopy

ABSTRACT Ultrafast outflows (UFOs) have been revealed in a large number of active galactic nuclei (AGN) and are regarded as promising candidates for AGN feedback on the host galaxy. The nature and launching mechanism of UFOs are not yet fully understood. Here we perform a time- and flux-resolved X-ray spectroscopy on four XMM–Newton observations of a highly accreting narrow-line Seyfert 1 (NLS1) galaxy, Mrk 1044, to study the dependence of the outflow properties on the source luminosity. We find that the UFO in Mrk 1044 responds to the source variability quickly and its velocity increases with the X-ray flux, suggesting a high-density ($10^{9}\!-\!4.5\times 10^{12}\, \mathrm{cm}^{-3}$) and radiatively driven outflow, launched from the region within a distance of $98\!-\!6600\, R_\mathrm{g}$ from the black hole. The kinetic energy of the UFO is conservatively estimated ($L_\mathrm{UFO}\sim 4.4~{{\ \rm per\ cent}}\, L_\mathrm{Edd}$), reaching the theoretical criterion to affect the evolution of the host galaxy. We also find that emission lines, from a large-scale region, have a blueshift of 2700–4500 km s−1 in the spectra of Mrk 1044, which is rarely observed in AGN. By comparing with other sources, we propose a correlation between the blueshift of emission lines and the source accretion rate, which can be verified by a future sample study.

Multiwavelength variability of γ-ray emitting narrow-line Seyfert 1 galaxies

ABSTRACT As one of the drivers of feedback in active galactic nuclei (AGNs), the jets launched from supermassive black holes (SMBHs) are important for understanding the co-evolution of SMBHs and their host galaxies. However, the formation of AGN jets is far from clear. The discovery of γ-ray narrow-line Seyfert 1 (NLS1) galaxies during the past two decades has provided us with a new means of studying the link between jets and accretion processes and the formation of jets. Here, we explore the coupling of jet and accretion discs in seven bright γ-ray NLS1 galaxies by studying simultaneous optical/ultraviolet and X-ray observations of these systems taken by Swift. The results show that, except for 1H 0323+342 in which the X-rays are significantly contributed from the accretion disc, the observed X-ray emission of the other sources is dominated by the jet, and accretion process makes little contribution if not absent. Although the origin of the X-ray emission is different, the broad-band spectral shape characterized by αox and the X-ray flux is found to follow the same evolutionary trend in 1H 0323+342, PMN J0948+0022, and PKS 1502+036. For the remaining sources, the trend is not observed or the sampling is not dense enough.

An XMM–Newton study of six narrow-line Seyfert 1 galaxies at z = 0.35–0.92

ABSTRACT We report a detailed analysis of the XMM–Newton spectra of six narrow-line Seyfert 1 (NLS1) galaxies at redshift z = 0.35–0.92. Compared with the NLS1s at lower redshift in the previously most-studied sample, these NLS1s have larger black hole (BH) masses ($\log \, M_\mathrm{BH}\gt 7.5$ ) with similar or even lower Eddington ratios. Our extended XMM–Newton sample of NLS1s shows strong soft X-ray excess emission below 2 keV. The quantified soft excess strength does not show an obvious discrepancy from previous studies of the lower redshift NLS1s. The systematic effect in the measurement of the Eddington ratio mainly lies in the bolometric correction factor. We also tentatively fit the spectra assuming two more physical models for the soft excess: warm Comptonization and relativistic reflection from the inner accretion disc. In the first scenario, we confirm the ubiquity of a warm and optically thick corona. The behaviour of a single source can be better explained by relativistic reflection, although we cannot distinguish which model is a more favourable explanation for the soft excess based on the best-fitting statistics.

Estimate of SMBH Spin for Narrow-Line Seyfert 1 Galaxies

We estimated the spin values of the supermassive black holes (SMBHs) of the active galactic nuclei (AGN) for a large set of Narrow Line Seyfert 1 (NLS1) galaxies assuming the inclination angle between the line of sight and the axis of the accretion disk to be approximately 45 degrees. We found that for these objects the spin values are on average less than for the Seyfert 1 galaxies that we studied previously. In addition, we found that the dependencies of the spin on the bolometric luminosity and the SMBH mass are two to three times stronger that for Seyfert 1 galaxies, which could mean that at early stages of evolution NLS1 galaxies either have a low accretion rate or chaotic accretion, while at later stages they have standard disk accretion, which very effectively increases the spin value.

The Radio Structure of the γ-Ray Narrow-line Seyfert 1 Galaxy SDSS J211852.96-073227.5

The γ-ray narrow-line Seyfert 1 (NLS1) galaxies can be considered to be the third class of γ-ray active galactic nuclei possessing relativistic jets. In this paper, we present multi-band high-resolution Very Long Baseline Array (VLBA) images of the γ-ray NLS1, SDSS J211852.96-073227.5 (J2118-0732, z = 0.26). We find a core-jet radio morphology and significant flux density variations in the radio core. The high brightness temperature estimated from VLBA images and core variability demonstrate that it exhibits substantial relativistic beaming effects. By considering radio emission in several bands, we find that the source has an inverted spectrum above 1 GHz but a steep spectrum at low frequencies ranging from 74 MHz–1 GHz; these may arise from the present activity and the old diffuse/extended emission, respectively. The core-jet morphology, significant flux density variations, and beaming effect make J2118-0732 resemble a blazar. Considering the low mass of its central black hole and the ongoing merger environment, J2118-0732 may represent a low-mass, low-power counterpart of blazars, and may finally evolve into a blazar.

The Close AGN Reference Survey (CARS)

Context. The interaction between active galactic nuclei (AGNs) and their host galaxies is scarcely resolved. Narrow-line Seyfert 1 (NLS1) galaxies are believed to represent AGN at early stages of their evolution and to allow one to observe feeding and feedback processes at high black hole accretion rates. Aims. We aim to constrain the properties of the ionised gas outflow in Mrk 1044, a nearby super-Eddington accreting NLS1. Based on the outflow energetics and the associated timescales, we estimate the outflow’s future impact on the ongoing host galaxy star formation on different spatial scales. Methods. We applied a spectroastrometric analysis to observations of Mrk 1044’s nucleus obtained with the adaptive-optics-assisted narrow field mode of the VLT/MUSE instrument. This allowed us to map two ionised gas outflows traced by [O III], which have velocities of −560 ± 20 km s−1 and −144 ± 5 km s−1. Furthermore, we used an archival spectrum from the Space Telescope Imaging Spectrograph on HST to identify two Ly-α absorbing components that escape from the centre with approximately twice the velocity of the ionised gas components. Results. Both [O III] outflows are spatially unresolved and located close to the AGN (< 1 pc). They have gas densities higher than 105 cm−3, which implies that the BPT diagnostic cannot be used to constrain the underlying ionisation mechanism. We explore whether an expanding shell model can describe the velocity structure of Mrk 1044’s multi-phase outflow. In the ionised gas emission, an additional outflowing component, which is spatially resolved, is present. It has a velocity of −211 ± 22 km s−1 and a projected size of 4.6 ± 0.6 pc. Our kinematic analysis suggests that significant turbulence is present in the interstellar medium around the nucleus, which may lead to a condensation rain, potentially explaining the efficient feeding of Mrk 1044’s AGN. Within the innermost 0.5″ (160 pc), we detect modest star formation hidden by the beam-smeared emission from the outflow. Conclusions. We estimate that the multi-phase outflow was launched < 104 yr ago. Together with the star formation in the vicinity of the nucleus, this suggests that Mrk 1044’s AGN phase started only recently. The outflow carries enough mass and energy to impact the host galaxy star formation on different spatial scales, highlighting the complexity of the AGN feeding and feedback cycle in its early stages.

The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition

Abstract We assemble a sample of 696 type 1 active galactic nuclei (AGN) up to a redshift of z = 2.5, all of which have an SDSS spectrum containing at least one broad emission line (H α, H β, or Mg ii) and an XMM-Newton X-ray spectrum containing at least 250 counts in addition to simultaneous optical/ultraviolet photometry from the XMM Optical Monitor. Our sample includes quasars and narrow-line Seyfert 1s: thus our AGN span a wide range in luminosity, black hole mass, and accretion rate. We determine single-epoch black hole mass relations for the three emission lines and find that they provide broadly consistent mass estimates whether the continuum or emission line luminosity is used as the proxy for the broad emission line region radius. We explore variations of the UV/X-ray energy index αox with the UV continuum luminosity and with black hole mass and accretion rate, and make comparisons to the physical quasar spectral energy distribution model qsosed. The majority of the AGN in our sample lie in a region of parameter space with 0.02 < L/LEdd < 2 as defined by this model, with narrow-line type 1 AGN offset to lower masses and higher accretion rates than typical broad-line quasars. We find differences in the dependence of αox on UV luminosity between both narrow/broad-line and radio-loud/quiet subsets of AGN: αox has a slightly weaker dependence on UV luminosity for broad-line AGN and radio-loud AGN have systematically harder αox.

Fast Outflowing Warm Absorbers in Narrow-line Seyfert 1 Galaxy PG 1001+054 Revealed by HST/COS Spectra

Narrow-line Seyfert 1 (NLS1) galaxies are an important type of active galactic nucleus (AGN), generally expected to be accreting at a high Eddington rate. The properties of their outflows and importance of AGN feedback remain intriguing. We report on the discovery of fast outflowing warm absorbers (WAs) in the NLS1 PG 1001+054 with velocities in the range of ∼7000–9000 km s−1. They are identified with blueshifted Lyα, N v, and Si iv lines in the high-resolution ultraviolet (UV) spectra taken with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. We perform photoionization modeling using XSTAR with three WAs. The derived physical properties are typical of WAs in terms of ionization and column density, whereas the outflow velocities are significantly higher. The estimated location of these WAs ranges from 1 to 73 parsecs away from the AGN. Together with previous detection of high ionization absorbers in the X-ray for PG 1001+054, we suggest that fast outflowing UV absorbers are probably part of a multiphase outflow. Such a structure is likely produced by the outflow launched from the AGN at an accretion disk scale, which shocks the ambient interstellar medium (ISM), producing stratified absorbers. Assuming contribution from the three WAs at tens of parsecs, the estimated ratio between the kinetic power of the outflow and AGN Eddington luminosity could reach 1.7%, raising the possibility of sufficient influence on the host galaxy when compared to some theoretical models for efficient AGN feedback.

On the Hadronic Origin of High-energy Emission of γ-Ray-loud Narrow-line Seyfert 1 PKS 1502+036

The radiation mechanism of Radio-Loud Narrow-Line Seyfert 1 (RL-NLS1) galaxies from X-ray to γ-ray bands remains an open question. While the leptonic model has been employed to explain the spectral energy distribution (SED), the hadronic process may potentially account for the high-energy radiation of some γ-ray-loud Narrow-Line Seyfert 1 (NLS1) galaxies as well. We study one of such RL-NLS1s, PKS 1502+036, comparing the theoretical SEDs predicted by the leptonic model and the lepto-hadronic model to the observed one. For the hadronic processes, we take into account the proton synchrotron radiation and proton–photon interactions (including the Bethe–Heitler process and the photopion process) including the emission of pairs generated in the electromagnetic cascade initiated by these processes. Our results show that the leptonic model can reproduce the SED of this source, in which the X-ray to γ-ray radiation can be interpreted as the inverse Compton scattering. On the other hand, the proton synchrotron radiation can also explain the high-energy component of SED although extreme parameters are needed. We also demonstrate that the p γ interactions as well as the cascade process cannot explain SED. Our results imply that a leptonic origin is favored for the multiwavelength emission of PKS 1502+036.