- ID:
- ivo://CDS.VizieR/J/MNRAS/509/2377
- Title:
- Narrow-Line Seyfert 1 IR Survey
- Short Name:
- J/MNRAS/509/2377
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present a near-infrared spectroscopic survey of narrow-line Seyfert 1 galaxies in the southern hemisphere (using the SOFI instrument on the ESO-NTT telescope), sampled from optical surveys. We examine the kinematics of the broad-line region, probed by the emission line width of hydrogen (Paschen{alpha} and H{beta}). We observed 57 objects, of which we could firmly measure Paschen{alpha} in 49 cases. We find that a single Lorentzian fit (preferred on theoretical grounds) is preferred over multi-component Gaussian fits to the line profiles; a lack of narrow-line region emission, overwhelmed by the pole-on view of the broad line region (BLR) light, supports this. We recompute the catalog black hole (BH) mass estimates, using the values of FWHM and luminosity of H{beta}, both from catalog values and re-fitted Lorentzian values. We find a relationship slope greater than unity compared to the catalog values. We ascribe this to contamination by galactic light or difficulties with line flux measurements. However, the comparison of masses computed by the fitted Lorentzian and Gaussian measurements show a slope close to unity. Comparing the BH masses estimated from both Paschen{alpha} and H{beta}, the line widths and fluxes shows deviations from expected; in general, however, the computed BH masses are comparable. We posit a scenario where an intermixture of dusty and dust-free clouds (or alternately a structured atmosphere) differentially absorbs the line radiation of the BLR, due to dust absorption and hydrogen bound-free absorption.
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- 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/ApJS/221/32
- Title:
- Narrow MgII absorption lines from SDSS-DR9Q
- Short Name:
- J/ApJS/221/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Data Release 9 Quasar spectra from the Baryonic Oscillation Spectroscopic Survey, which does not include quasar spectra from the Sloan Digital Sky Survey Data Release 7, we detect narrow MgII{lambda}{lambda}2796,2803 absorption doublets in the spectral data redward of 1250{AA} (quasar rest frame) until the red wing of the MgII{lambda}2800 emission line. Our survey is limited to quasar spectra with a median signal-to-noise ratio <S/N>{>=}4/pixel in the surveyed spectral region, resulting in a sample that contains 43260 quasars. We have detected a total of 18598 MgII absorption doublets with 0.2933<=z_abs_<=2.6529. About 75% of absorbers have an equivalent width at rest frame of W_r_^{lambda}2796^. About 75% of absorbers have doublet ratios (DR=W_r_^{lambda}2796^/W_r_^{lambda}2803^) in the range of 1<=DR<=2, and about 3.2% lie outside the range of 1-{sigma}_DR_<=DR<=2+{sigma}_DR_. We characterize the detection false positives/negatives by the frequency of detected MgII absorption doublets in the limits of the S/N of the spectral data. The S/N=4.5 limit is assigned a completeness fraction of 53% and tends to be complete when the S/N is greater than 4.5. The redshift number densities of all of the detected MgII absorbers moderately increase from z~0.4 to z~1.5, which parallels the evolution of the cosmic star formation rate density. Limiting our investigation to those quasars whose emission redshift can be determined from narrow emission lines, the relative velocities ({beta}) of MgII absorbers have a complex distribution which probably consists of three classes of MgII absorbers: (1) cosmologically intervening absorbers; (2) environmental absorbers that reside within the quasar host galaxies or galaxy clusters; (3) quasar outflow absorbers. After subtracting contributions from cosmologically intervening absorbers and environmental absorbers, the {beta} distribution of the MgII might mainly be contributed by the quasar outflow absorbers and peaks at {upsilon}~1500km/s. This peak velocity is lower than the value of 2000km/s found in statistical analysis of CIV absorbers.
- ID:
- ivo://CDS.VizieR/J/A+A/307/869
- Title:
- Nature of the peculiar supergiant HD 101584
- Short Name:
- J/A+A/307/869
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of low- and high-resolution ultraviolet, high-resolution optical CAT/CES spectra and ultraviolet, optical and infrared photometry of the peculiar supergiant HD 101584. From the photometry we learn that the ultraviolet and optical energy distribution cannot be fitted in a consistent way and we need a model in which the UV and optical energy distribution are formed by different gas. The Geneva photometry is best fitted to a B9II Kurucz model, T_eff_=12000+/-1000K and logg=3.0+/-1.0, with an extinction of E(B-V)=0.49+/-0.05. The observed spectral features in the spectrum of HD 101584 are classified in eight different categories based on the velocity, shape of profile and the identification. The high-excitation HeI ({chi}=20.87eV), NII ({chi}=18.40eV), CII ({chi}=14.39eV) and NI ({chi}=10.29eV) optical absorption lines are formed in the photosphere of a late B-star (e.g. B8-9I-II). These absorption lines show radial velocity variations which are attributed to binary motion, with the secondary being a white dwarf or a low-mass main sequence object. The low-excitation P-Cygni lines in the optical and UV are formed in the wind. The number density of absorption lines in the UV is so large that the wind spectrum acts as an iron curtain in front of the B-star. The terminal velocity of the wind of v_{infinity}_=100+/-30km/s is consistent with the star being a low-mass post-AGB star and the low effective gravity is attributed to the presence of a nearby, unseen, secondary. We estimate a mass-loss rate of M{dot}=~10^-8^M_{sun}_/yr. Narrow absorption and emission lines are observed which are formed in a circumsystem disk with a typical radius of 10^2^R_*_.
- ID:
- ivo://CDS.VizieR/J/A+A/433/497
- Title:
- Nearby early-type galaxies with ionized gas. I.
- Short Name:
- J/A+A/433/497
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With the aim of building a data-set of spectral properties of well studied early-type galaxies showing emission lines, we present intermediate resolution spectra of 50 galaxies in the nearby Universe. The sample, which covers several of the E and S0 morphological sub-classes, is biased toward objects that might be expected to have ongoing and recent star formation, at least in small amounts, because of the presence of the emission lines. The emission is expected to come from the combination of active galactic nuclei and star formation regions within the galaxies. Sample galaxies are located in environments corresponding to a broad range of local galaxy densities, although predominantly in low density environments. Our long-slit spectra cover the 3700-7250{AA} wavelength range with a spectral resolution of approximately 7.6{AA} at 5550{AA}. The specific aim of this paper, and our first step in the investigation, is to map the underlying galaxy stellar population by measuring, along the slit positioned along the galaxy major axis, line-strength indices at several, homogeneous galacto-centric distances. For each object we extracted 7 luminosity-weighted apertures (with radii 1.5", 2.5", 10", r_e/10_, r_e/8_, r_e/4_ and r_e/2_) corrected for the galaxy ellipticity and 4 gradients (0<r<r_e/16_, r_e/16_<r<r_e/8_, r_e/8_<r<r_e/4_ and r_e/4_<r<r_e/2_). For each aperture and gradient we measured 25 line-strength indices: 21 of the set defined by the Lick-IDS ``standard'' system (Trager et al., 1998, Cat. J/ApJS/116/1) and 4 introduced by Worthey & Ottaviani (1997, Cat. J/ApJS/111/377). Line-strength indices have been transformed to the Lick-IDS system. Indices derived then include H{beta}, Mg_1_, Mg_2_, Mgb, MgFe, Fe5270, Fe5335 commonly used in classic index-index diagrams. The paper introduces the sample, presents the observations, describes the data reduction procedures, the extraction of apertures and gradients, the determination and correction of the line-strength indices, the procedure adopted to transform them into the Lick-IDS System and the procedures adopted for the emission correction. We finally discuss the comparisons between our dataset and line-strength indices available in the literature. A significant fraction, about 60%, of galaxies in the present sample has one previous measurement in the Lick-IDS system but basically restricted within the r_e/8_ region. Line-strength measures obtained both from apertures and gradients outside this area and within the r_e/8_ region, with the present radial mapping, are completely new.
- ID:
- ivo://CDS.VizieR/J/A+A/445/79
- Title:
- Nearby early-type gal. with ionized gas. II.
- Short Name:
- J/A+A/445/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Rampazzo et al., 2005, Cat. <J/A+A/433/497> (Paper I) presented a data-set of line-strength indices for 50 early-type galaxies in the nearby Universe. The galaxy sample is biased toward galaxies showing emission lines, located in environments corresponding to a broad range of local galaxy densities, although predominantly in low density environments. The present addendum enlarges the above data-set of line-strength indices by analyzing 18 additional early-type galaxies (three galaxies, NGC 3607, NGC 5077 and NGC 5898 were presented in the previous set). We measured 25 line-strength indices, defined by the Lick IDS "standard" system (Trager et al., 1998, Cat. <J/ApJS/116/1>; Worthey & Ottaviani, 1997, Cat. <J/ApJS/111/377>), for 7 luminosity weighted apertures and 4 gradients of each galaxy. This addendum presents the line-strength data-set and compares it with the available data in the literature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/1743
- Title:
- Nearby galaxies abundances
- Short Name:
- J/MNRAS/471/1743
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine samples of nearby galaxies with Herschel photometry selected on their dust, metal, HI and stellar mass content, and compare these to chemical evolution models in order to discriminate between different dust sources. In a companion paper, we used an HI-selected sample of nearby galaxies to reveal a subsample of very gas-rich (gas fraction >80 per cent) sources with dust masses significantly below predictions from simple chemical evolution models, and well below M_d_/M_*_ and M_d_/M_gas_ scaling relations seen in dust and stellar-selected samples of local galaxies. We use a chemical evolution model to explain these dust-poor, but gas-rich, sources as well as the observed star formation rates (SFRs) and dust-to-gas ratios. We find that (i) a delayed star formation history is required to model the observed SFRs; (ii) inflows and outflows are required to model the observed metallicities at low gas fractions; (iii) a reduced contribution of dust from supernovae (SNe) is needed to explain the dust-poor sources with high gas fractions. These dust-poor, low stellar mass galaxies require a typical core-collapse SN to produce 0.01-0.16M_{sun}_ of dust. To match the observed dust masses at lower gas fractions, significant grain growth is required to counteract the reduced contribution from dust in SNe and dust destruction from SN shocks. These findings are statistically robust, though due to intrinsic scatter it is not always possible to find one single model that successfully describes all the data. We also show that the dust-to-metal ratio decreases towards lower metallicity.
- ID:
- ivo://CDS.VizieR/J/A+A/428/877
- Title:
- 4 nearby galaxies velocities & line-strengths
- Short Name:
- J/A+A/428/877
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of four nearby early-type galaxies previously known (Rest et al., 2001AJ....121.2431R) to have nuclear stellar disks using two instruments on-board the Hubble Space Telescope. We observed NGC 4128, NGC 4612, and NGC 5308 with the Wide Field Planetary Camera 2, and the same three galaxies, plus NGC 4570, with the Space Telescope Imaging Spectrograph. We have detected a red nucleus in NGC 4128, a blue nucleus in NGC 4621, and a blue disk in NGC 5308. Additionally, we have discovered a blue disk-like feature with position angle ~15{deg} from the major axis in NGC 4621. In NGC 5308 there is evidence for a blue region along the minor axis. We discovered a blue transient on the images of NGC 4128 at position 0.14" west and 0.32" north from the nucleus. The extracted kinematic profiles belong to two groups: fast (NGC 4570 and NGC 5308) and kinematically disturbed rotators (NGC 4128 and NGC 4621). We report the discovery of a kinematically decoupled core in NGC 4128. Galaxies have mostly old (10-14Gyr) stellar populations with large spread in metallicities (sub- to super-solar). We discuss the possible formation scenarios, including bar-driven secular evolution and the influence of mergers, which can explain the observed color and kinematic features.
- ID:
- ivo://CDS.VizieR/J/ApJ/814/40
- Title:
- Nearby galaxy filaments with UV obs.
- Short Name:
- J/ApJ/814/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Simulations of the formation of large-scale structures predict that dark matter, low density highly ionized gas, and galaxies form 10 to 40Mpc scale filaments. These structures are easily recognized in the distribution of galaxies. Here we use Ly{alpha} absorption lines to study the gas in 30x6Mpc filament at cz~3500km/s, defined using a new catalog of nearby (cz<10000km/s) galaxies, which is complete down to a luminosity of about 0.05L_*_ for the region of space analyzed here. Using Hubble Space Telescope spectra of 24 active galactic nuclei, we sample the gas in this filament. All of our sightlines pass outside the virial radius of any known filament galaxy. Within 500kpc of the filament axis the detection rate is ~80%, but no detections are seen more than 2.1Mpc from the filament axis. The width of the Ly{alpha} lines correlates with filament impact parameter and the four BLAs in our sample occur within 400kpc of the filament axis, indicating increased temperature and/or turbulence. Comparing to simulations, we find that the recent Haardt & Madau extragalactic ionizing background predicts a factor of 3-5 too few ionizing photons. Using a more intense radiation field matches the hydrogen density profile within 2.1Mpc of the filament axis, but the simulations still overpredict the detection rate between 2.1 and 5Mpc from the axis. The baryonic mass inside filament galaxies is 1.4x10^13^M_{sun}_, while the mass of filament gas outside galaxy halos is found to be 5.2x10^13^M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/524/536
- Title:
- Nearby Ly{alpha} quasar absorbers
- Short Name:
- J/ApJ/524/536
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopy of 10 quasars obtained with the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) is presented. In the 10 sight lines, we detect 357 absorption lines above a significance level of 3{sigma} and 272 lines above a significance level of 4.5{sigma}. Automated software is used to detect and identify the lines, almost all of which are unresolved at the GHRS G140L resolution of 200km/s. After identifying Galactic lines, intervening metal lines, and higher order Lyman lines, we are left with 139 Ly{alpha} absorbers in the redshift range 0<z<0.22 (lines within 900km/s of geocoronal Ly{alpha} are not selected). These diffuse hydrogen absorbers have column densities that are mostly in the range 10^13^-10^15^cm^-2^ for an assumed Doppler parameter of 30km/s. The number density of lines above a rest equivalent width of 0.24{AA}, dN/dz=38.3{+/-}5.3, agrees well with the measurement from the Quasar Absorption-Line Key Project. There is marginal evidence for cosmic variance in the number of absorbers detected among the 10 sight lines.
