scholarly journals BAL and non-BAL quasars: continuum, emission, and absorption properties establish a common parent sample

2020 ◽  
Vol 492 (3) ◽  
pp. 4553-4575 ◽  
Author(s):  
Amy L Rankine ◽  
Paul C Hewett ◽  
Manda Banerji ◽  
Gordon T Richards
Keyword(s):  
Physical Properties ◽  
Emission Line ◽  
Mean Field ◽  
Sloan Digital Sky Survey ◽  
Continuum Emission ◽  
Spectral Energy ◽  
Absorption Properties ◽  
Broad Absorption Line ◽  
High Ionization ◽  
Common Parent

ABSTRACT Using a sample of ≃144 000 quasars from the Sloan Digital Sky Survey Data Release 14, we investigate the outflow properties, evident in both absorption and emission, of high-ionization broad absorption line (BAL) and non-BAL quasars with redshifts 1.6 ≲ $z$ ≤ 3.5 and luminosities 45.3 erg s−1 < log10(Lbol) < 48.2 erg s−1. Key to the investigation is a continuum and emission-line reconstruction scheme, based on mean-field independent component analysis, that allows the kinematic properties of the C iv λ1550 emission line to be compared directly for both non-BAL and BAL quasars. C iv emission blueshift and equivalent width (EW) measurements are thus available for both populations. Comparisons of the emission-line and BAL trough properties reveal strong systematic correlations between the emission and absorption properties. The dependence of quantitative outflow indicators on physical properties such as quasar luminosity and luminosity relative to Eddington luminosity is also shown to be essentially identical for the BAL and non-BAL populations. There is an absence of BALs in quasars with the hardest spectral energy distributions (SEDs), revealed by the presence of strong He ii λ1640 emission, large C iv λ1550 emission EW, and no measurable blueshift. In the remainder of the C iv emission blueshift versus EW space, BAL and non-BAL quasars are present at all locations; for every BAL quasar, it is possible to identify non-BAL quasars with the same emission-line outflow properties and SED hardness. The co-location of BAL and non-BAL quasars as a function of emission-line outflow and physical properties is the key result of our investigation, demonstrating that (high-ionization) BALs and non-BALs represent different views of the same underlying quasar population.

scholarly journals Big Three Dragons: A [N ii] 122 μm Constraint and New Dust-continuum Detection of a z = 7.15 Bright Lyman-break Galaxy with ALMA

2021 ◽  
Vol 923 (1) ◽  
pp. 5
Author(s):  
Yuma Sugahara ◽  
Akio K. Inoue ◽  
Takuya Hashimoto ◽  
Satoshi Yamanaka ◽  
Seiji Fujimoto ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
Far Infrared ◽  
Abundance Ratio ◽  
Continuum Emission ◽  
Spectral Energy ◽  
High Ionization ◽  
The Galaxy ◽  
Infrared Spectral ◽  
Best Fit ◽  
Redshift Galaxies

Abstract We present new Atacama Large Millimeter/submillimeter Array Band 7 observational results of a Lyman-break galaxy at z = 7.15, B14-65666 (“Big Three Dragons”), which is an object detected in [O iii] 88 μm, [C ii] 158 μm, and dust continuum emission during the epoch of reionization. Our targets are the [N ii] 122 μm fine-structure emission line and the underlying 120 μm dust continuum. The dust continuum is detected with a ∼19σ significance. From far-infrared spectral energy distribution sampled at 90, 120, and 160 μm, we obtain a best-fit dust temperature of 40 K (79 K) and an infrared luminosity of log 10 ( L IR / L ⊙ ) = 11.6 (12.1) at the emissivity index β = 2.0 (1.0). The [N ii] 122 μm line is not detected. The 3σ upper limit of the [N ii] luminosity is 8.1 × 107 L ⊙. From the [N ii], [O iii], and [C ii] line luminosities, we use the Cloudy photoionization code to estimate nebular parameters as functions of metallicity. If the metallicity of the galaxy is high (Z > 0.4 Z ⊙), the ionization parameter and hydrogen density are log 10 U ≃ − 2.7 ± 0.1 and n H ≃ 50–250 cm−3, respectively, which are comparable to those measured in low-redshift galaxies. The nitrogen-to-oxygen abundance ratio, N/O, is constrained to be subsolar. At Z < 0.4 Z ⊙, the allowed U drastically increases as the assumed metallicity decreases. For high ionization parameters, the N/O constraint becomes weak. Finally, our Cloudy models predict the location of B14-65666 on the BPT diagram, thereby allowing a comparison with low-redshift galaxies.

scholarly journals Properties of LBGs with [OIII] detection at z ∼ 3.5

2019 ◽  
Vol 631 ◽  
pp. A123 ◽  
Author(s):  
Fang-Ting Yuan ◽  
Denis Burgarella ◽  
David Corre ◽  
Veronique Buat ◽  
Médéric Boquien ◽  
...  
Keyword(s):  
Physical Properties ◽  
Emission Line ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Formation Rate ◽  
Line Emission ◽  
Stellar Mass ◽  
Spectral Energy ◽  
Emission Data ◽  
The Impact

Context. Nebular emission lines are critical to measure physical properties in the ionized gas (e.g., metallicity, the star formation rate, or dust attenuation). They also account for a significant fraction of broadband fluxes, in particular at the highest redshifts, and therefore can strongly affect the determination of other physical properties, such as the stellar mass, which are crucial in shaping our understanding of galaxy formation and evolution. Aims. We investigate a sample of 51 Lyman break galaxies at 3.0 <  zspec <  3.8 with detected [OIII] line emissions and estimated the physical properties of these galaxies to examine the impact of including nebular emission data in the Spectral energy distribution (SED) fitting. Methods. We used the Code Investigating GALaxy Emission (CIGALE) to fit the rest-frame ultraviolet-to-near-infrared SEDs of these galaxies and their emission line data simultaneously. We ran CIGALE with and without the nebular model or the emission line data, and compare the results to show the importance of including the nebular emission line data in the SED fitting. Results. We find that without the nebular model, the SED fitting overestimates the stellar mass due to the strong [OIII] lines that are redshifted to the Ks-band, which is consistent with previous results. The emission line data are necessary to constrain the nebular model in the SED fitting. We examine the Ks-band excess, which is mostly used to estimate the emissions of the [OIII]+Hβ lines when there is no spectral data, and we find that the estimation and observation are statistically consistent. However, the difference can reach up to more than 1 dex in some catastrophic cases, which shows the importance of obtaining spectroscopic measurements for these lines. We also estimate the equivalent width of the Hβ absorption and find it negligible compared to the Hβ emission. Conclusions. Line emission is important to constrain the nebular models and to obtain reliable estimates of the physical properties of galaxies. These data should be taken into account in the SED fitting.

scholarly journals The Sloan Digital Sky Survey Quasar Catalog: Fourteenth data release

2018 ◽  
Vol 613 ◽  
pp. A51 ◽  
Author(s):  
Isabelle Pâris ◽  
Patrick Petitjean ◽  
Éric Aubourg ◽  
Adam D. Myers ◽  
Alina Streblyanska ◽  
...  
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Wavelength Region ◽  
Principal Component ◽  
Sloan Digital Sky Survey ◽  
Large Area ◽  
Robust Identification ◽  
Broad Absorption Line ◽  
Sky Survey ◽  
Data Release

We present the data release 14 Quasar catalog (DR14Q) from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV). This catalog includes all SDSS-IV/eBOSS objects that were spectroscopically targeted as quasar candidates and that are confirmed as quasars via a new automated procedure combined with a partial visual inspection of spectra, have luminosities Mi [z = 2] < −20.5 (in a Λ CDM cosmology with H0 = 70 km s−1 Mpc−1, Ω M =0.3, and Ω Λ = 0.7), and either display at least one emission line with a full width at half maximum larger than 500 km s−1 or, if not, have interesting/complex absorption features. The catalog also includes previously spectroscopically-confirmed quasars from SDSS-I, II, and III. The catalog contains 526 356 quasars (144 046 are new discoveries since the beginning of SDSS-IV) detected over 9376 deg2 (2044 deg2 having new spectroscopic data available) with robust identification and redshift measured by a combination of principal component eigenspectra. The catalog is estimated to have about 0.5% contamination. Redshifts are provided for the Mg II emission line. The catalog identifies 21 877 broad absorption line quasars and lists their characteristics. For each object, the catalog presents five-band (u, g, r, i, z) CCD-based photometry with typical accuracy of 0.03 mag. The catalog also contains X-ray, ultraviolet, near-infrared, and radio emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra, covering the wavelength region 3610–10 140 Å at a spectral resolution in the range 1300 < R < 2500, can be retrieved from the SDSS Science Archiver Server.

scholarly journals The correlations between optical/UV broad lines and X-ray emission for a large sample of quasars

2019 ◽  
Vol 492 (1) ◽  
pp. 719-741 ◽  
Author(s):  
John D Timlin ◽  
W N Brandt ◽  
Q Ni ◽  
B Luo ◽  
Xingting Pu ◽  
...  
Keyword(s):  
Emission Line ◽  
Rest Frame ◽  
Spectral Energy Distribution ◽  
Uv Spectra ◽  
Sloan Digital Sky Survey ◽  
Observation Angle ◽  
Spectral Energy ◽  
X Ray ◽  
Uv Emission ◽  
Best Fitting

ABSTRACT We present Chandra observations of 2106 radio-quiet quasars in the redshift range 1.7 ≤ z ≤ 2.7 from the Sloan Digital Sky Survey (SDSS), through data release 14 (DR14), that do not contain broad absorption lines in their rest-frame ultraviolet (UV) spectra. This sample adds over a decade worth of SDSS and Chandra observations to our previously published sample of 139 quasars from SDSS DR5 that is still used to correlate X-ray and optical/UV emission in typical quasars. We fit the SDSS spectra for 753 of the quasars in our sample that have high-quality (exposure time ≥ 10 ks and off-axis observation angle ≤ 10 arcmin) X-ray observations, and analyse their X-ray-to-optical spectral energy distribution properties (αox and  Δαox) with respect to the measured C iv and Mg ii emission-line rest-frame equivalent width (EW) and the C iv emission-line blueshift. We find significant correlations (at the ≥99.99 per cent level) between  αox and these emission-line parameters, as well as between  Δαox and  $\rm{C \, \small{IV}}$ EW. Slight correlations are found between  Δαox and  $\rm{C \, \small{IV}}$ blueshift, $\rm{Mg \, \small{II}}$ EW, and the  $\rm{C \, \small{IV}}$ EW to $\rm{Mg \, \small{II}}$ EW ratio. The best-fitting trend in each parameter space is used to compare the X-ray weakness (Δαox) and optical/UV emission properties of typical quasars and weak-line quasars (WLQs). The WLQs typically exhibit weaker X-ray emission than predicted by the typical quasar relationships. The best-fitting relationships for our typical quasars are consistent with predictions from the disc–wind quasar model. The behaviour of the WLQs compared to our typical quasars can be explained by an X-ray ‘shielding’ model.

scholarly journals A Catalog of Host Galaxies for WISE-selected AGN: Connecting Host Properties with Nuclear Activity and Identifying Contaminants

2021 ◽  
Vol 922 (2) ◽  
pp. 179
Author(s):  
R. Scott Barrows ◽  
Julia M. Comerford ◽  
Daniel Stern ◽  
Roberto J. Assef
Keyword(s):  
Star Formation ◽  
Physical Properties ◽  
Significant Negative Correlation ◽  
Continuum Emission ◽  
Host Galaxy ◽  
Spectral Energy ◽  
Wide Field ◽  
Host Galaxies ◽  
Bolometric Luminosity ◽  
Sphere Of Influence

Abstract We present a catalog of physical properties for galaxies hosting active galactic nuclei (AGN) detected by the Wide-field Infrared Survey Explorer (WISE). By fitting broadband spectral energy distributions of sources in the WISE AGN Catalog with empirical galaxy and AGN templates, we derive photometric redshifts, AGN bolometric luminosities, measures of AGN obscuration, host galaxy stellar masses, and host galaxy star formation rates (SFRs) for 695,273 WISE AGN. The wide-area nature of this catalog significantly augments the known number of obscured AGN out to redshifts z ∼ 3 and will be useful for studies focused on AGN or their host galaxy physical properties. We first show that the most likely non-AGN contaminants are galaxies at redshifts z = 0.2–0.3, with relatively blue W1–W2 colors, and with high specific SFRs for which the dust continuum emission is elevated in the W2 filter. Toward increasingly lower redshifts, WISE AGN host galaxies have systematically lower specific SFRs relative to those of normal star-forming galaxies, likely due to decreased cold gas fractions and the time delay between global star formation and AGN triggering. Finally, WISE AGN obscuration is not strongly correlated with AGN bolometric luminosity but shows a significant negative correlation with the Eddington ratio. This result is consistent with a version of the receding torus model in which the obscuring material is located within the supermassive black hole gravitational sphere of influence and the dust inner radius increases due to radiation pressure.

scholarly journals Broad Absorption Line QSOs

1986 ◽  
Vol 119 ◽  
pp. 317-330 ◽  
Author(s):  
David A. Turnshek
Keyword(s):  
Emission Line ◽  
Absorption Line ◽  
Observational Constraints ◽  
Broad Absorption ◽  
Central Source ◽  
Broad Absorption Line ◽  
Broad Emission ◽  
Line Region ◽  
High Ionization ◽  
Broad Emission Line

Observational constraints on models for broad absorption line (BAL) QSOs are discussed. The picture which emerges is one in which the broad absorption line region (BALR) contributes to the broad emission line region (ELR) as a high ionization component. Depending on QSO luminosity, the limits on the distance of the BALR from the central source are 1–1000 pc. A highly metal enriched and disk-like geometry for the region is indicated. The similarity between the absorption in some radio quiet BAL QSOs and the associated complexes of absorption in some radio loud QSOs may indicate that the BALR outflow can affect the region surrounding a QSO out to distances in excess of several hundred kpc.

REVIEW : KARAKTERISTIK FISIK DAN DAYA IRITASI MINYAK ATSIRI BUNGA CENGKEH (Syzygium aromaticum) DALAM BEBERAPA TIPE BASIS SEBAGAI ANTI-INFLAMASI

2020 ◽  
Vol 5 (2) ◽  
pp. 364-375
Author(s):  
Amraini Amelia ◽  
◽  
Nining Sugihartini ◽  
Hari Susanti ◽  
Keyword(s):  
Essential Oil ◽  
Physical Properties ◽  
Research Method ◽  
Water Soluble ◽  
Syzygium Aromaticum ◽  
Absorption Properties ◽  
Inflammatory Drugs ◽  
Clove Essential Oil ◽  
Soluble Base ◽  
Essential Oil Formulations

This review aims to determine the types of bases that can be used every day, which are effective and efficient as anti-inflammatory drugs. The research method used was to review the development of clove essential oil formulations that have been carried out using various concentrations of various types of bases including M / A type cream, A / M type cream, water soluble base, lotion, emulgel, hydrocarbons, hydrogels and absorbents. The recommended formulation is type M / A cream with a concentration of 5% clove flower essential oil. The types of bases studied were M / A cream, type A / M cream, water soluble base, lotion, emulgel, hydrocarbons, hydrogels and absorption properties which had good physical properties and did not irritate the skin of the test animals. This review refers to several national and international journals released in the last ten years, from 2010 to 2020.

scholarly journals Gaia-assisted discovery of a detached low-ionisation BAL quasar with very large ejection velocities

2020 ◽  
Vol 634 ◽  
pp. A111 ◽  
Author(s):  
J. P. U. Fynbo ◽  
P. Møller ◽  
K. E. Heintz ◽  
J. N. Burchett ◽  
L. Christensen ◽  
...  
Keyword(s):  
Emission Line ◽  
Absorption Line ◽  
Emission Lines ◽  
Broad Absorption ◽  
Broad Absorption Line ◽  
Red Edge ◽  
First Case ◽  
Bl Lac ◽  
Spatially Extended ◽  
Extended Emission

We report on the discovery of a peculiar broad absorption line (BAL) quasar identified in our Gaia-assisted survey of red quasars. The systemic redshift of this quasar was difficult to establish because of the absence of conspicuous emission lines. Based on deep and broad BAL troughs of at least Si IV, C IV, and Al III, a redshift of z = 2.41 was established under the assumption that the systemic redshift can be inferred from the red edge of the BAL troughs. However, we observe a weak and spatially extended emission line at 4450 Å that is most likely due to Lyman-α emission, which implies a systemic redshift of z = 2.66 if correctly identified. There is also evidence for the onset of Lyman-α forest absorption bluewards of 4450 Å and evidence for Hα emission in the K band consistent with a systemic redshift of z = 2.66. If this redshift is correct, the quasar is an extreme example of a detached low-ionisation BAL quasar. The BALs must originate from material moving with very large velocities ranging from 22 000 km s−1 to 40 000 km s−1. To our knowledge, this is the first case of a systemic-redshift measurement based on extended Lyman-α emission for a BAL quasar. This method could also be useful in cases of sufficiently distant BL Lac quasars without systemic-redshift information.

scholarly journals Reproducing the Universe: a comparison between the EAGLE simulations and the nearby DustPedia galaxy sample

2020 ◽  
Vol 494 (2) ◽  
pp. 2823-2838 ◽  
Author(s):  
Ana Trčka ◽  
Maarten Baes ◽  
Peter Camps ◽  
Sharon E Meidt ◽  
James Trayford ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Physical Properties ◽  
Numerical Models ◽  
Far Infrared ◽  
Spectral Energy ◽  
Star Forming ◽  
Star Forming Regions ◽  
Global Emission ◽  
Galaxy Sample ◽  
Galaxy Population

ABSTRACT We compare the spectral energy distributions (SEDs) and inferred physical properties for simulated and observed galaxies at low redshift. We exploit UV-submillimetre mock fluxes of ∼7000 z = 0 galaxies from the EAGLE suite of cosmological simulations, derived using the radiative transfer code skirt. We compare these to ∼800 observed galaxies in the UV-submillimetre range, from the DustPedia sample of nearby galaxies. To derive global properties, we apply the SED fitting code cigale consistently to both data sets, using the same set of ∼80 million models. The results of this comparison reveal overall agreement between the simulations and observations, both in the SEDs and in the derived physical properties, with a number of discrepancies. The optical and far-infrared regimes, and the scaling relations based upon the global emission, diffuse dust, and stellar mass, show high levels of agreement. However, the mid-infrared fluxes of the EAGLE galaxies are overestimated while the far-UV domain is not attenuated enough, compared to the observations. We attribute these discrepancies to a combination of galaxy population differences between the samples and limitations in the subgrid treatment of star-forming regions in the EAGLE-skirt post-processing recipe. Our findings show the importance of detailed radiative transfer calculations and consistent comparison, and provide suggestions for improved numerical models.

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