Detecting Gas Outflows in Type-2 AGNs Selected from the Sloan Digital Sky Survey

2012 ◽  
Vol 8 (S292) ◽  
pp. 372-372
Author(s):  
Hyun-Jin Bae ◽  
Jong-Hak Woo ◽  
Semyeong Oh
Keyword(s):  
Galaxy Evolution ◽  
Critical Role ◽  
Sloan Digital Sky Survey ◽  
Host Galaxies ◽  
Star Forming ◽  
Line Region ◽  
Systemic Velocity ◽  
Stellar Component ◽  
Sky Survey

AbstractEnergetic outflow from active galactic nuclei (AGNs) may play a critical role in galaxy evolution (e.g., Silk & Rees 1998). We present a velocity diagnostic for detecting gas outflow in the narrow-line region of Type-2 AGNs using line-of-sight velocity offsets of the [O iii] λ5007 and Hα emission lines with respect to the systemic velocity of stars in host galaxies (See Figure 1). We apply the diagnostics to nearby galaxies at 0.02 < z < 0.05, 3775 AGN-host and 907 star-forming galaxies as a comparison sample, which are selected from the Sloan Digital Sky Survey DR7. After obtaining a best-fit stellar population model for the continuum and a systemic velocity based on stellar lines, we subtract the stellar component to measure velocity offsets of each emission line. We find a sample of 169 AGN-host galaxies with outflow signatures, displaying a larger velocity shift of [O iii] than that of Hα, as expected in a decelerating outflow model (Komossa et al. 2008). We find that the offset velocity of [O iii] increases with Eddington ratio, suggesting that gas outflow depends on the energetics of AGN.

scholarly journals The optically selected 1.4-GHz quasar luminosity function below 1 mJy

2020 ◽  
Vol 492 (4) ◽  
pp. 5297-5312 ◽  
Author(s):  
Eliab Malefahlo ◽  
Mario G Santos ◽  
Matt J Jarvis ◽  
Sarah V White ◽  
Jonathan T L Zwart
Keyword(s):  
Luminosity Function ◽  
Significant Contribution ◽  
Detection Threshold ◽  
Simulated Data ◽  
Sloan Digital Sky Survey ◽  
Radio Luminosity ◽  
Host Galaxies ◽  
Star Forming ◽  
Sky Survey ◽  
Radio Luminosity Function

ABSTRACT We present the radio luminosity function (RLF) of optically selected quasars below 1 mJy, constructed by applying a Bayesian-fitting stacking technique to objects well below the nominal radio flux density limit. We test the technique using simulated data, confirming that we can reconstruct the RLF over three orders of magnitude below the typical 5σ detection threshold. We apply our method to 1.4-GHz flux densities from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey, extracted at the positions of optical quasars from the Sloan Digital Sky Survey over seven redshift bins up to z = 2.15, and measure the RLF down to two orders of magnitude below the FIRST detection threshold. In the lowest redshift bin (0.2 &lt; z &lt; 0.45), we find that our measured RLF agrees well with deeper data from the literature. The RLF for the radio-loud quasars flattens below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 25.5$ and becomes steeper again below $\log _{10}[L_{1.4}/{\rm W\, Hz}^{-1}] \approx 24.8$, where radio-quiet quasars start to emerge. The radio luminosity where radio-quiet quasars emerge coincides with the luminosity where star-forming galaxies are expected to start dominating the radio source counts. This implies that there could be a significant contribution from star formation in the host galaxies, but additional data are required to investigate this further. The higher redshift bins show a similar behaviour to the lowest z bin, implying that the same physical process may be responsible.

scholarly journals SFR Relation with Galaxy Environment and Colour at z between 0.03 and 0.1

2006 ◽  
Vol 2 (S235) ◽  
pp. 234-235
Author(s):  
Premana W. Premadi ◽  
A. Sitti Maryam
Keyword(s):  
Galaxy Evolution ◽  
Sloan Digital Sky Survey ◽  
Emission Lines ◽  
Limited Sample ◽  
Data Set ◽  
Star Forming ◽  
Diagnostic Diagram ◽  
Sky Survey ◽  
Data Release ◽  
Galaxy Environment

This work is a preliminary result of our attempt to examine the use of SFR in the study of galaxy evolution. For this purpose we use the Sloan Digital Sky Survey Data Release 2 (SDSS DR2) Abazajian et al. (2004) and the SFR Catalogue generated from this data set by Brinchmann et al. (2004) and Kaufmann et al. (2003). Following Kewley et al. (2001) we use the Diagnostic Diagram, log ([OIII]/Hβ) vs log ([NII]/Hα), to separate the star forming galaxies from other emission lines sources such as AGN. Choosing only those with S/N > 3 out of the Brinchmann et al. (2004) catalogue, we arrive at about 200 thousand galaxies as our starting SFR subsample. With 0.05 < z < 0.22 and limit at r = 17.77, the subsample can be used to reconstruct the properties of a volume limited sample of galaxies with M* = 6 1010Modot. We benefit from the fact that Brinchmann et al. (2004) SFR Catalogue has already been aperture-corrected using the likelihood distribution P(SFR/Li/colour) scheme. For the environment, we use the data generated by Kaufmann et al. (2003), and arrive at about 40 thousand target galaxies. In this work the environment is characterised by the number (N=0-30) of neighbouring galaxies within a projected radius of 2 Mpc and velocity di.erence of 500km/s from each target galaxy, and the magnitude limit is 14.5 < r < 17.77.

scholarly journals The Chemical Enrichment and Mass Assembly Histories of SDSS Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 307-307
Author(s):  
R. Cid Fernandes ◽  
N. V. Asari ◽  
J. P. Torres-Papaqui ◽  
W. Schoenell ◽  
L. Sodré ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Synthesis Method ◽  
Sloan Digital Sky Survey ◽  
Population Synthesis ◽  
Star Forming ◽  
Chemical Enrichment ◽  
Sky Survey ◽  
Wide Range ◽  
Mass Assembly ◽  
Evolution Systems

AbstractWe explore the mass-assembly and chemical enrichment histories of star forming galaxies by applying a population synthesis method to a sample of nearly 70k galaxies culled from over 500k galaxies from the Sloan Digital Sky Survey Data Release 5. Our method decomposes the entire observed spectrum in terms of a sum of simple stellar populations spanning a wide range of ages and metallicities, thus allowing the reconstruction of galaxy histories. A comparative study of galaxy evolution is presented, where galaxies are grouped onto bins of nebular abundances or mass. We find that galaxies whose warm interstellar medium is poor in heavy elements are slow in forming stars. Their stellar metallicities also rise slowly with time, reaching their current values (Z⋆ ~ 1/4Z⊙) in the last ~100 Myr of evolution. Systems with metal rich nebulae, on the other hand, assembled most of their mass and completed their chemical evolution long ago, reaching Z⋆ ~ Z⊙ already at lookback times of a few Gyr. These same trends, which are ultimately a consequence of galaxy downsizing, appear when galaxies are grouped according to their stellar mass. The reconstruction of galaxy histories to this level of detail out of integrated spectra offers promising prospects in the field of galaxy evolution theories.

Outflows & Feedback from Extremely Red Quasars

2020 ◽  
Vol 15 (S359) ◽  
pp. 232-237
Author(s):  
Fred Hamann ◽  
Serena Perrotta ◽  
Nadia Zakamska
Keyword(s):  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Sloan Digital Sky Survey ◽  
Emission Lines ◽  
Host Galaxies ◽  
Broad Absorption ◽  
Feedback Effects ◽  
Broad Emission ◽  
Sky Survey ◽  
High Incidence

AbstractFeedback from accreting supermassive black holes is often invoked in galaxy evolution models to inhibit star formation, truncate galaxy growth, and establish the observed black-hole/bulge mass correlation. We are studying outflows and feedback in a unique sample of extremely red quasars (ERQs) during the peak epoch of galaxy formation (at redshifts 2.3 < z < 3.4). We identified ERQs in the Sloan Digital Sky Survey III (SDSS-III) Baryon Oscillation Spectroscopic Survey (BOSS) quasar catalog based on their extremely red i–W3 colors, but we find that ERQs typically have a suite of other extreme properties including 1) a high incidence of blueshifted broad absorption lines, 2) broad emission lines with unusually large rest equivalent widths (REWs), peculiar “wingless” profiles, and frequent large blueshifts (reaching ˜8740 km s-1), and 3) characteristically very broad and blueshifted [OIII] 4959,5007Å lines that trace ionized outflows at speeds up to ˜6700 km s-1. We propose that these ERQs represent a young quasar population with powerful outflows on the precipice of causing important disruptive feedback effects in their host galaxies.

scholarly journals MASSIVE STAR-FORMING HOST GALAXIES OF QUASARS ON SLOAN DIGITAL SKY SURVEY STRIPE 82

2013 ◽  
Vol 780 (2) ◽  
pp. 162 ◽  
Author(s):  
Yoshiki Matsuoka ◽  
Michael A. Strauss ◽  
Ted N. Price ◽  
Matthew S. DiDonato
Keyword(s):  
Massive Star ◽  
Sloan Digital Sky Survey ◽  
Host Galaxies ◽  
Star Forming ◽  
Sky Survey

ERRATUM: “MASSIVE STAR-FORMING HOST GALAXIES OF QUASARS ON SLOAN DIGITAL SKY SURVEY STRIPE 82” (2014, ApJ, 780, 162)

2014 ◽  
Vol 789 (1) ◽  
pp. 91 ◽  
Author(s):  
Yoshiki Matsuoka ◽  
Michael A. Strauss ◽  
Ted N. Price ◽  
Matthew S. DiDonato
Keyword(s):  
Massive Star ◽  
Sloan Digital Sky Survey ◽  
Host Galaxies ◽  
Star Forming ◽  
Sky Survey

scholarly journals Characterizing the abundance, properties, and kinematics of the cool circumgalactic medium of galaxies in absorption with SDSS DR16

2021 ◽  
Vol 504 (1) ◽  
pp. 65-88
Author(s):  
Abhijeet Anand ◽  
Dylan Nelson ◽  
Guinevere Kauffmann
Keyword(s):  
Formation Rate ◽  
Sloan Digital Sky Survey ◽  
Gas Absorption ◽  
Dark Matter Halo ◽  
Star Forming ◽  
Sky Survey ◽  
Optical Continuum ◽  
Circumgalactic Medium ◽  
Emission Line Galaxies ◽  
Red Galaxies

ABSTRACT In order to study the circumgalactic medium (CGM) of galaxies we develop an automated pipeline to estimate the optical continuum of quasars and detect intervening metal absorption line systems with a matched kernel convolution technique and adaptive S/N criteria. We process ∼ one million quasars in the latest Data Release 16 (DR16) of the Sloan Digital Sky Survey (SDSS) and compile a large sample of ∼ 160 000 Mg ii absorbers, together with ∼ 70 000 Fe ii systems, in the redshift range 0.35 &lt; zabs &lt; 2.3. Combining these with the SDSS DR16 spectroscopy of ∼1.1 million luminous red galaxies (LRGs) and ∼200 000 emission line galaxies (ELGs), we investigate the nature of cold gas absorption at 0.5 &lt; z &lt; 1. These large samples allow us to characterize the scale dependence of Mg ii with greater accuracy than in previous work. We find that there is a strong enhancement of Mg ii absorption within ∼50 kpc of ELGs, and the covering fraction within 0.5rvir of ELGs is 2–5 times higher than for LRGs. Beyond 50 kpc, there is a sharp decline in Mg ii for both kinds of galaxies, indicating a transition to the regime where the CGM is tightly linked with the dark matter halo. The Mg ii-covering fraction correlates strongly with stellar mass for LRGs, but weakly for ELGs, where covering fractions increase with star formation rate. Our analysis implies that cool circumgalactic gas has a different physical origin for star-forming versus quiescent galaxies.

scholarly journals The weak imprint of environment on the stellar populations of galaxies

2020 ◽  
Vol 500 (4) ◽  
pp. 4469-4490 ◽  
Author(s):  
James Trussler ◽  
Roberto Maiolino ◽  
Claudia Maraston ◽  
Yingjie Peng ◽  
Daniel Thomas ◽  
...  
Keyword(s):  
Environmental Effects ◽  
Unique Feature ◽  
Stellar Populations ◽  
Stellar Mass ◽  
Sloan Digital Sky Survey ◽  
Star Forming ◽  
Sky Survey ◽  
Satellite Galaxies ◽  
Projected Distance ◽  
Environmental Dependence

ABSTRACT We investigate the environmental dependence of the stellar populations of galaxies in Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Echoing earlier works, we find that satellites are both more metal-rich (&lt;0.1 dex) and older (&lt;2 Gyr) than centrals of the same stellar mass. However, after separating star-forming, green valley, and passive galaxies, we find that the true environmental dependence of both stellar metallicity (&lt;0.03 dex) and age (&lt;0.5 Gyr) is in fact much weaker. We show that the strong environmental effects found when galaxies are not differentiated result from a combination of selection effects brought about by the environmental dependence of the quenched fraction of galaxies, and thus we strongly advocate for the separation of star-forming, green valley, and passive galaxies when the environmental dependence of galaxy properties are investigated. We also study further environmental trends separately for both central and satellite galaxies. We find that star-forming galaxies show no environmental effects, neither for centrals nor for satellites. In contrast, the stellar metallicities of passive and green valley satellites increase weakly (&lt;0.05 and &lt;0.08 dex, respectively) with increasing halo mass, increasing local overdensity and decreasing projected distance from their central; this effect is interpreted in terms of moderate environmental starvation (‘strangulation’) contributing to the quenching of satellite galaxies. Finally, we find a unique feature in the stellar mass–stellar metallicity relation for passive centrals, where galaxies in more massive haloes have larger stellar mass (∼0.1 dex) at constant stellar metallicity; this effect is interpreted in terms of dry merging of passive central galaxies and/or progenitor bias.

scholarly journals Searching for Mg ii absorbers in and around galaxy clusters

2021 ◽  
Vol 503 (3) ◽  
pp. 4309-4319
Author(s):  
Jong Chul Lee ◽  
Ho Seong Hwang ◽  
Hyunmi Song
Keyword(s):  
Galaxy Clusters ◽  
Detection Rate ◽  
Massive Star ◽  
Sloan Digital Sky Survey ◽  
Number Density ◽  
Cluster Galaxies ◽  
Star Forming ◽  
Quasar Spectra ◽  
Sky Survey ◽  
The Galaxy

ABSTRACT To study environmental effects on the circumgalactic medium (CGM), we use the samples of redMaPPer galaxy clusters, background quasars, and cluster galaxies from the Sloan Digital Sky Survey (SDSS). With ∼82 000 quasar spectra, we detect 197 Mg ii absorbers in and around the clusters. The detection rate per quasar is 2.7 ± 0.7 times higher inside the clusters than outside the clusters, indicating that Mg ii absorbers are relatively abundant in clusters. However, when considering the galaxy number density, the absorber-to-galaxy ratio is rather low inside the clusters. If we assume that Mg ii absorbers are mainly contributed by the CGM of massive star-forming galaxies, a typical halo size of cluster galaxies is smaller than that of field galaxies by 30 ± 10 per cent. This finding supports that galaxy haloes can be truncated by interaction with the host cluster.

scholarly journals Spitzer IRS Observations of Low-Mass Seyfert Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 268-268
Author(s):  
Carol E. Thornton ◽  
Aaron J. Barth ◽  
Luis C. Ho ◽  
Jenny E. Greene
Keyword(s):  
Dust Emission ◽  
Seyfert Galaxies ◽  
Sloan Digital Sky Survey ◽  
Physical Conditions ◽  
Sky Survey ◽  
Low Mass ◽  
Ngc 4395 ◽  
Black Hole Masses

The Sloan Digital Sky Survey has made it possible to identify the first samples of active galaxies with estimated black hole masses below ~ 106M⊙. We have obtained Spitzer IRS low-resolution spectra, covering 5–38 μm, of a sample of 41 Seyfert galaxies with low-mass black holes. Our sample includes SDSS-selected objects from the low-mass Seyfert 1 sample of Greene & Ho (2004) and the low-mass Seyfert 2 sample of Barth et al. (2008), as well as NGC 4395 and POX 52. The goals of this work are to examine the dust emission properties of these objects and investigate the relationship between type 1 and type 2 AGNs at low luminosities and low masses, to search for evidence of star formation, and to use emission-line diagnostics to constrain physical conditions within the narrow-line regions. Here we present preliminary results from this project.

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