- ID:
- ivo://CDS.VizieR/J/A+A/459/55
- Title:
- Narrow-band imaging of 5 Seyfert-1 galaxies
- Short Name:
- J/A+A/459/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spatially resolved emission-line spectroscopy is a powerful tool to determine the physical conditions in the narrow-line region (NLR) of active galactic nuclei (AGNs). We recently used optical long-slit spectroscopy to study the NLRs of a sample of six Seyfert-2 galaxies. We have shown that such an approach, in comparison to the commonly used [OIII] narrow-band imaging alone, allows us to probe the size of the NLR in terms of AGN photoionisation. Moreover, several physical parameters of the NLR can be directly accessed. We here apply the same methods to study the NLR of six Seyfert-1 galaxies and compare our results to those of Seyfert-2 galaxies. We employ diagnostically valuable emission-line ratios to determine the physical properties of the NLR, including the core values and radial dependencies of density, ionisation parameter, and reddening. Tracking the radial change of emission-line ratios in diagnostic diagrams allows us to measure the transition between AGN-like and HII-like line excitation, and thus we are able to measure the size of the NLR. In the diagnostic diagrams, we find a transition between line ratios falling in the AGN regime and those typical for HII regions in two Seyfert-1 galaxies, thus determining the size of the NLR. The central electron temperature and ionisation parameter are in general higher in type-1 Seyferts than in type 2s. In almost all cases, both electron density and ionisation parameter decrease with radius. In general, the decrease is faster in Seyfert-1 galaxies than in type 2s. In several objects, the gaseous velocity distribution is characteristic for rotational motion in an (inclined) emission-line disk in the centre. We give estimates of the black hole masses. We discuss our findings in detail for each object.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/618/L83
- Title:
- Narrow iron K{alpha} lines in AGN
- Short Name:
- J/ApJ/618/L83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We assemble a sample consisting of 66 active galactic nuclei (AGNs) from the literature (Page et al., 2004MNRAS.347..316P) and from the XMM-Newton archive in order to investigate the origin of the 6.4keV narrow iron K{alpha} line (NIKAL). The X-ray Baldwin effect of the NIKAL is confirmed in this sample.
- ID:
- ivo://CDS.VizieR/J/ApJS/229/39
- Title:
- Narrow line Seyfert 1 galaxies from SDSS-DR12
- Short Name:
- J/ApJS/229/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of narrow-line Seyfert 1 (NLSy1) galaxies from the Sloan Digital Sky Survey Data Release 12 (SDSS DR12). This was obtained by a systematic analysis through modeling of the continuum and emission lines of the spectra of all the 68859 SDSS-DR12 objects that are classified as "QSO" by the SDSS spectroscopic pipeline with z<0.8 and a median signal-to-noise ratio (S/N)>2/pixel. This catalog contains a total of 11101 objects, which is about 5 times larger than the previously known NLSy1 galaxies. Their monochromatic continuum luminosity at 5100{AA} is found to be strongly correlated with H{beta}, H{alpha}, and [OIII] emission line luminosities. The optical FeII strength in NLSy1 galaxies is about two times larger than the broad-line Seyfert 1 (BLSy1) galaxies. About 5% of the catalog sources are detected in the FIRST survey. The Eddington ratio ({xi}_Edd_) of NLSy1 galaxies has an average of log({xi}_Edd_) of -0.34, much higher than -1.03 found for BLSy1 galaxies. Their black hole masses (M_BH_) have an average of log(M_BH_) of 6.9M_{sun}_, which is less than BLSy1 galaxies, which have an average of log(M_BH_) of 8.0M_{sun}_. The M_BH_ of NLSy1 galaxies is found to be correlated with their host galaxy velocity dispersion. Our analysis suggests that geometrical effects playing an important role in defining NLSy1 galaxies and their M_BH_ deficit is perhaps due to their lower inclination compared to BLSy1 galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJS/166/128
- Title:
- Narrow line Seyfert 1 galaxies from SDSS-DR3
- Short Name:
- J/ApJS/166/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a systematic search for narrow line Seyfert 1 galaxies (NLS1s) from objects assigned as "QSOs" or "galaxies" in the spectroscopic sample of the Sloan Digital Sky Survey Data Release 3 (SDSS DR3) by a careful modeling of their emission lines and continua. The result is a uniform sample comprising ~2000 NLS1s. This sample dramatically increases the number of known NLS1s by a factor of ~10 over previous compilations. This paper presents the parameters of the prominent emission lines and continua, which were measured accurately with typical uncertainties <10%. Taking advantage of such an unprecedented large and uniform sample with accurately measured spectral parameters, we carried out various statistical analyses, some of which were only possible for the first time.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A13
- Title:
- Narrow line Seyfert 1 (NLS1) galaxies spectra
- Short Name:
- J/A+A/615/A13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Many active galactic nuclei (AGN) and particularly narrow line Seyfert 1 (NLS1) galaxies, usually exhibit blueshifts and blue wings in several emission lines, which are mainly associated to outflows and strong winds. Although there is no clear evidence of the physical origin of the [OIII] blue wings, it has been suggested that they could be emitted from the inner parts of the narrow line region (NLR). In order to study the radial velocity difference between the narrow component of H{beta} and the core component of [OIII]{lambda}5007 and the asymmetric emission of this forbidden line, we investigate a sample of NLS1 galaxies. One of the aims of this paper is to analyze the blue wings of the [OIII]{lambda}5007 profiles and their relation with the central engine. We have obtained and studied medium-resolution spectra (190km/s FWHM at H{beta}) of a sample of 28 NLS1 galaxies in the optical range 4300-5200{AA}. We performed Gaussian decomposition to the H{beta} and [OIII]{lambda}{lambda}4959,5007 emission profiles in order to study the distinct components of these lines. A new blue outlier galaxy is found, with the center of the core component of [OIII] blueshifted by 405km/s relative to the center of the narrow component of H{beta} line. We confirmed a previously known correlation between the blueshift and the FWHM of the core component of [OIII]{lambda}5007 line. We also corroborated the correlation between the latter and the velocity of the centroid of the blue wing. On the other hand, studying the radial velocity difference between the blue end of the asymmetric emission and the centroid of the core component of [OIII], we found a correlation between it and the central black hole mass and, therefore, with the luminosity of the broad component of H{beta}. Finally, we found a moderate correlation between the luminosity of the [OIII] blue wing and the black hole mass. These results suggest that the asymmetric emission of the [OIII] lines is related to the central engine, not only through the black hole but also in the intensity of the AGN, in agreement with previous results.
- ID:
- ivo://CDS.VizieR/J/A+A/577/A135
- Title:
- Nearby AGN ^12^CO and H{alpha} maps
- Short Name:
- J/A+A/577/A135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of the relation between star formation rate (SFR) surface density ({Sigma}_SFR_) and mass surface density of molecular gas ({Sigma}_H2_), commonly referred to as the Kennicutt-Schmidt (K-S) relation, at its intrinsic spatial scale, i.e. the size of giant molecular clouds (~10-150pc), in the central, high-density regions of four nearby low-luminosity active galactic nuclei (AGN). These are AGN extracted from NUclei of GAlaxies (NUGA) survey. This study is aimed at investigating the correlations and slopes of the K-S relation, as a function of spatial resolution and of different ^12^CO emission lines used to trace {Sigma}_H2_, and testing its validity in the high-density central regions of spiral galaxies. We used interferometric IRAM ^12^CO(1-0) and ^12^CO(2-1), and SMA ^12^CO(3-2) emission line maps to derive {Sigma}_H2_ and HS T-H{alpha} to estimate {Sigma}_SFR_.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A95
- Title:
- NEP raster ROSAT X-ray/Optical catalog
- Short Name:
- J/A+A/645/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The North-Ecliptic Pole is an important region for extragalactic surveys. Deep/wide contiguous surveys are being performed by several space observatories. We analyse all ROSAT pointed and survey observations within 40deg^2^ around the NEP, restricting the field-of-view to the inner 30' radius. We obtain an X-ray catalogue of 805 sources with 0.5-2keV fluxes >2.9*10^-15^erg/cm^2^/s, a factor of three deeper than the ROSAT All-Sky Survey in this field. The sensitivity and angular resolution of our data are comparable to the eROSITA All-Sky Survey expectations. The 50% position error radius of the sample of X-ray sources is ~10". We use HEROES optical and near-infrared imaging photometry from Subaru and CFHT telescopes together with literature catalogues and a new deep and wide Spitzer survey in the field to identify X-ray sources and calculate photometric redshifts for the candidate counterparts. In particular we utilize mid-IR colours to identify AGN X-ray counterparts. Despite relatively large error circles and faint counterparts, confusion and systematic errors, we obtain a rather reliable catalogue of 766 optical counterparts, redshifts and optical classifications. We find a new population of luminous absorbed X-ray AGN at large redshifts, not recognized in previous X-ray surveys, but identified in our work due to the unique combination of survey solid angle, X-ray sensitivity and multiwavelength photometry. We also use the WISE and Spitzer photometry to identify a sample of 185 AGN selected purely through mid-IR colours, most of which are not detected by ROSAT. Their redshifts and upper limits to X-ray luminosity and X-ray-to-optical flux ratios are even higher than for the new class of X-ray selected luminous type 2 AGN (AGN2); they are probably a natural extension of this sample. This unique dataset is important as a reference sample for future deep surveys in the NEP region, in particular for eROSITA and also for Euclid and SPHEREX. We predict that most of the absorbed distant AGN should be readily picked up by eROSITA, but they require sensitive mid-IR imaging to be recognized as optical counterparts.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/95
- Title:
- [NeV] or [NeIII] double peaked SDSS quasars
- Short Name:
- J/ApJ/769/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 131 quasars from the Sloan Digital Sky Survey at redshifts 0.8<z<1.6 with double peaks in either of the high-ionization narrow emission lines [NeV]{lambda}3426 or [NeIII]{lambda}3869. These sources were selected with the intention of identifying high-redshift analogs of the z<0.8 active galactic nuclei (AGNs) with double-peaked [OIII]{lambda}5007 lines, which might represent AGN outflows or dual AGNs. Lines of high ionization potential are believed to originate in the inner, highly photoionized portion of the narrow line region, and we exploit this assumption to investigate the possible kinematic origins of the double-peaked lines. For comparison, we measure the [NeV]{lambda}3426 and [NeIII]{lambda}3869 double peaks in low-redshift (z<0.8) [OIII]-selected sources. We find that [NeV]{lambda}3426 and [NeIII]{lambda}3869 show a correlation between line splitting and line width similar to that of [OIII]{lambda}5007 in other studies, and the velocity splittings are correlated with the quasar Eddington ratio. These results suggest an outflow origin for at least a subset of the double peaks, allowing us to study the high-ionization gas kinematics around quasars. However, we find that a non-negligible fraction of our sample show no evidence for an ionization stratification. For these sources, the outflow scenario is less compelling, leaving the dual AGN scenario as a viable possibility. Finally, we find that our sample shows an anti-correlation between the velocity-offset ratio and luminosity ratio of the components, which is a potential dynamical argument for the presence of dual AGNs. Therefore, this study serves as a first attempt at extending the selection of candidate dual AGNs to higher redshifts.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/66
- Title:
- New Fermi/LAT extragalactic sources
- Short Name:
- J/ApJ/742/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of 2.1 years of Fermi Large Area Telescope (LAT) data on 491 Seyfert galaxies detected by the Swift Burst Alert Telescope (BAT) survey. Only the two nearest objects, NGC 1068 and NGC 4945, which were identified in the Fermi first year catalog (Abdo et al. 2010, Cat. J/ApJ/715/429), are detected. Using Swift/BAT and radio 20cm fluxes, we define a new radio-loudness parameter R_X,BAT_ where radio-loud objects have logR_X,BAT_> -4.7. Based on this parameter, only radio-loud sources are detected by Fermi/LAT. An upper limit to the flux of the undetected sources is derived to be ~2x10^-11^photons/cm^2^/s, approximately seven times lower than the observed flux of NGC 1068. Assuming a median redshift of 0.031, this implies an upper limit to the {gamma}-ray (1-100GeV) luminosity of <~3x10^41^erg/s. In addition, we identified 120 new Fermi/LAT sources near the Swift/BAT Seyfert galaxies with significant Fermi/LAT detections. A majority of these objects do not have Swift/BAT counterparts, but their possible optical counterparts include blazars, flat-spectrum radio quasars, and quasars.
- ID:
- ivo://CDS.VizieR/J/ApJ/670/92
- Title:
- New sample of low-mass black holes in AGN
- Short Name:
- J/ApJ/670/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an expanded sample of low-mass black holes (BHs) found in galactic nuclei. Using standard virial mass techniques to estimate BH masses, we select from the Fourth Data Release of the Sloan Digital Sky Survey all broad-line active galaxies with masses <2x10^6^M_{sun}_ BHs in this mass regime provide unique tests of the relationship between BHs and galaxies, since their late-type galaxy hosts do not necessarily contain classical bulges. Furthermore, they provide observational analogs of primordial seed BHs and are expected, when merging, to provide strong gravitational signals for future detectors such as LISA. From our preliminary sample of 19, we have increased the total sample by an order of magnitude to 174, as well as an additional 55 (less secure) candidates.
