- 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.
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Search Results
- 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.
- ID:
- ivo://CDS.VizieR/J/AJ/142/78
- Title:
- New 2.2<z<3 quasars from SDSS and UKIDSS
- Short Name:
- J/AJ/142/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The identification of quasars in the redshift range 2.2<z<3 is known to be very inefficient because the optical colors of such quasars are indistinguishable from those of stars. Recent studies have proposed using optical variability or near-infrared (near-IR) colors to improve the identification of the missing quasars in this redshift range. Here we present a case study combining both methods. We select a sample of 70 quasar candidates from variables in Sloan Digital Sky Survey (SDSS) Stripe 82, which are non-ultraviolet excess sources and have UKIDSS near-IR public data. They are clearly separated into two parts on the Y-K/g-z color-color diagram, and 59 of them meet or lie close to a newly proposed Y-K/g-z selection criterion for z<4 quasars. Of these 59 sources, 44 were previously identified as quasars in SDSS DR7, and 35 of them are quasars at 2.2<z<3. We present spectroscopic observations of 14 of 15 remaining quasar candidates using the Bok 2.3m telescope and the MMT 6.5m telescope, and successfully identify all of them as new quasars at z=2.36-2.88. We also apply this method to a sample of 643 variable quasar candidates with SDSS-UKIDSS nine-band photometric data selected from 1875 new quasar candidates in SDSS Stripe 82 given by Butler & Bloom (2011AJ....141...93B) based on the time-series selections, and find that 188 of them are probably new quasars with photometric redshifts at 2.2<z<3. Our results indicate that the combination of optical variability and optical/near-IR colors is probably the most efficient way to find 2.2<z<3 quasars and is very helpful for constructing a complete quasar sample. We discuss its implications for ongoing and upcoming large optical and near-IR sky surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A104
- Title:
- NGC 1377 ALMA CO 3-2 and 0.8mm continuum images
- Short Name:
- J/A+A/640/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Submillimetre and millimetre line and continuum observations are important in probing the morphology, column density, and dynamics of the molecular gas and dust around obscured active galactic nuclei (AGNs) and their mechanical feedback. With very high resolution (0.02"x0.03" (2x3pc)) ALMA 345GHz observations of CO 3-2, HCO^+^ 4-3, vibrationally excited HCN 4-3 {nu}_2_=1f , and continuum we have studied the remarkable, extremely radio-quiet, molecular jet and wind of the lenticular galaxy NGC 1377. The outflow structure is resolved, revealing a 150pc long, clumpy, high-velocity (600km/s), collimated molecular jet where the molecular emission is emerging from the spine of the jet with an average diameter of 3-7pc. The jet widens to 10-15pc about 25pc from the centre, which is possibly due to jet-wind interactions. A narrow-angle (50-70), misaligned and rotating molecular wind surrounds the jet, and both are enveloped by a larger-scale CO-emitting structure at near-systemic velocity. The jet and narrow wind have steep radial gas excitation gradients and appear turbulent with high gas dispersion (>40km/s). The jet shows velocity reversals that we propose are caused by precession, or more episodic directional changes. We discuss the mechanisms powering the outflow, and we find that an important process for the molecular jet and narrow wind is likely magneto-centrifugal driving. In contrast, the large-scale CO-envelope may be a slow wind, or cocoon that stems from jet-wind interactions. An asymmetric, nuclear r~2pc dust structure with a high inferred molecular column density N(H_2_)=1.8x10^24^cm^-2^ is detected in continuum and also shows compact emission from vibrationally excited HCN. The nuclear dust emission is hot (Td>180K) and its luminosity is likely powered by a buried AGN. The lopsided structure appears to be a warped disk, which is responsible for a significant part of the nuclear obscuration and possibly formed as a result of uneven gas inflows. The dynamical mass inside r=1.4pc is estimated to 9^+2^_3_x10^6^M_{sun}_, implying that the supermassive black hole (SMBH) has a high mass with respect to the stellar velocity dispersion of NGC 1377. We suggest that the SMBH of NGC 1377 is currently in a state of moderate growth, at the end of a more intense phase of accretion and also evolving from a state of more extreme nuclear obscuration. The nuclear growth may be fuelled by low-angular momentum gas inflowing from the gas ejected in the molecular jet and wind. Such a feedback-loop of cyclic outflows and central accretion could explain why there is still a significant reservoir of molecular gas in this ageing, lenticular galaxy. A feedback-loop would be an effective process in growing the nuclear SMBH and thus would constitute an important phase in the evolution of NGC 1377. This also invites new questions as to SMBH growth processes in obscured, dusty galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A33
- Title:
- NGC 613 ALMA datacubes
- Short Name:
- J/A+A/632/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report ALMA observations of CO(3-2) emission in the Seyfert/nuclear starburst galaxy NGC613, at a spatial resolution of 17pc, as part of our NUclei of GAlaxies (NUGA) sample. Our aim is to investigate the morphology and dynamics of the gas inside the central kiloparsec, and to probe nuclear fueling and feedback phenomena. The morphology of CO(3-2) line emission reveals a two arm trailing nuclear spiral at r<~100pc and a circumnuclear ring at a radius of ~350pc that is coincident with the star-forming ring seen in the optical images. Also, we find evidence for a filamentary structure connecting the ring and the nuclear spiral. The ring reveals two breaks into two winding spiral arms corresponding to the dust lanes in the optical images. The molecular gas in the galaxy disk is in a remarkably regular rotation, however the kinematics in the nuclear region are very skewed. The nuclear spectrum of CO and dense gas tracers HCN(4-3), HCO^+^(4-3), and CS(7-6) show broad wings up to 300km/s, associated with a molecular outflow emanating from the nucleus (r~25pc). We derive a molecular outflow mass M_out_=2x10^6^M_[sun}_ and a mass outflow rate of dM_out_/dt=27M_[sun}/yr. The molecular outflow energetics exceed the values predicted by AGN feedback models: the kinetic power of the outflow corresponds to P_K,out_=20%L_AGN_ and the momentum rate is dM_out_/dt*v~400L_AGN_/c. The outflow is mainly boosted by the AGN through entrainment by the radio jet, but given the weak nuclear activity of NGC613, we might be witnessing a fossil outflow resulting from a previously strong AGN that has now faded. Furthermore, the nuclear trailing spiral observed in CO emission is inside the inner Lindblad resonance ring of the bar. We compute the gravitational torques exerted in the gas to estimate the efficiency of the angular momentum exchange. The gravity torques are negative from 25 to 100pc and the gas loses its angular momentum in a rotation period, providing evidence for a highly efficient inflow towards the center. This phenomenon shows that the massive central black hole has significant dynamical influence on the gas, triggering the inflowing of molecular gas to feed the black hole.
