Erratum: “Space Density of Optically Selected Type 2 Quasars” (2008, Aj, 136, 2373)

Reyes, Reinabelle; Zakamska, Nadia L.; Strauss, Michael A.; Green, Joshua; Krolik, Julian H.; Shen, Yue; Richards, Gordon T.; Anderson, Scott F.; Schneider, Donald P.

doi:10.1088/0004-6256/139/3/1295

Cited by 178 publications

(484 citation statements)

References 7 publications

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“…As Hα is redshifted out of the optical bandpass at z 0.5 > , alternative obscured AGN selection methods using observed optical spectra have been developed to capitalize on the existing rich data sets from wide-area optical surveys, including: Gilli et al 2010;Mignoli et al 2013) 20 ; 5. a combination of narrow emission lines withFWHMva-lues <2000 km s −1 , ratios of narrow emission lines suggesting AGNs rather than star formation ionization, and a high [O III] luminosity, which is applicable between z 0.3 0.83 < < (Zakamska et al 2003;Reyes et al 2008); 6. strong C IV and Lyα emission with FWHM <2000 km s −1 and weak rest-frame ultraviolet continuum values, which identifies AGNs between z 2 4.3 < < (Alexandroff et al 2013; see also Steidel et al 2002;Hainline et al 2011).…”

Section: Identifying Type 2 Agnsmentioning

confidence: 99%

On R − W1 as a Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-Ray Surveys

LaMassa

Civano

Brusa

et al. 2016

ApJ

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Capitalizing on the all-sky coverage of WISEand the 35% and 50% sky coverage from Sloan Digital Sky Survey and Pan-STARRS, respectively, we explore the efficacy of-, as a color diagnostic to identify obscured supermassive black hole accretion in wide-area X-ray surveys. We use the ∼16.5 deg 2 Stripe 82 X-ray survey data as a testbed to compare R W1 -with R−K, an oft-used obscured active galactic nucleus (AGN) selection criterion, and examine where different classes of objects lie in this parameter space. Most stars follow a well-defined path in R−K versus R W1space. We demonstrate that optically normal galaxies hosting X-ray AGNs at redshifts z 0.5 1 < < can be recovered with an R W1 4 -> colorcut, while they typically are not selected as AGNs based on their W W 1 2 -colors. Additionally, different observed X-ray luminosity bins favor different regions in R W1 -parameter space: moderate-luminosity AGNs > -erg s −1 ) have bluer colors; higher spectroscopic completeness of the Stripe 82X sample is needed to determine whether this is a selection effect or an intrinsic property. Finally, we parameterize X-ray obscuration of Stripe 82X AGNs by calculating their hardness ratios (HRs) and find no clear trends between HR and optical reddening. Our results will help inform best-effort practices in followingup obscured AGN candidates in current and future wide-area, shallow X-ray surveys, including the all-sky eROSITA mission.

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Section: Identifying Type 2 Agnsmentioning

confidence: 99%

On R − W1 as a Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-Ray Surveys

LaMassa

Civano

Brusa

et al. 2016

ApJ

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“…QSO2s candidates taken from Zakamska et al (2003) and Reyes et al (2008) as well as a handful of X-ray selected objects (see Sect. 8.1 below) having a reliable match in the 2XMMi catalogue were added to the identified sample.…”

Section: Building An Identified Samplementioning

confidence: 99%

“…L [OIII] > 10 8.3 L (Zakamska et al 2003;Reyes et al 2008). X-ray selection looks instead for luminous (L X,2−10 keV > 10 44 erg/s) significantly obscured (column density N H > 10 22 cm −2 ) sources, which are best selected in the E > 2 keV hard X-ray band (e.g.…”

Section: Searching For Qso2 Candidatesmentioning

confidence: 99%

“…The optically selected sample has been obtained by cross-correlating the SDSS sample of Zakamska et al (2003) and Reyes et al (2008) with the 2XMMi catalogue. We list in Table 9 the main properties of the QSO2 SDSS candidates matching a serendipitous EPIC source.…”

Section: Searching For Qso2 Candidatesmentioning

confidence: 99%

“…Table 9. QSO2 candidates from Zakamska et al (2003), Reyes et al (2008) and X-ray selected samples matching 2XMMi entries with EPIC pn observations. Notes.…”

Section: Fig 8 Left Panelmentioning

confidence: 99%

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Cross-correlation of the 2XMMi catalogue with Data Release 7 of the Sloan Digital Sky Survey

Pineau

Motch

Carrera

et al. 2011

A&A

102

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The Survey Science Centre of the XMM-Newton satellite released the first incremental version of the 2XMM catalogue in August 2008. Containing more than 220 000 X-ray sources, the 2XMMi was at that time the largest catalogue of X-ray sources ever published and thus constitutes an unprecedented resource for studying the high-energy properties of various classes of X-ray emitters such as AGN and stars. Thanks to the high throughput of the EPIC cameras on board XMM-Newton accurate positions, fluxes, and hardness ratios are available for a substantial fraction of the X-ray detections. The advent of the 7th release of the Sloan Digital Sky Survey offers the opportunity to cross-match two major surveys and extend the spectral energy distribution of many 2XMMi sources towards the optical bands. This implies building extensive homogeneous samples with a statistically controlled rate of spurious matches and completeness. We here present a cross-matching algorithm based on the classical likelihood ratio estimator. The method developed has the advantage of providing true probabilities of identifications without resorting to heavy Monte-Carlo simulations. Over 30,000 2XMMi sources have SDSS counterparts with individual probabilities of identification higher than 90%. At this threshold, the sample has only 2% spurious matches and contains 77% of all expected SDSS identifications. Using spectroscopic identifications from the SDSS DR7 catalogue supplemented by extraction from other catalogues, we build an identified sample from which the way the various classes of X-ray emitters gather in the multi dimensional parameter space can be analysed and later used to design a source classification scheme. We illustrate the interest of this clean source sample by investigating two scientific use cases. In the first example we show how these multi-wavelength data can be used to search for new QSO2s. Although no specific range of observed properties allows us to efficiently identify Compton Thick QSO2s, we show that the prospects are much better for Compton Thin AGN2 and discuss several possible multi-parameter selection strategies. In a second example, we confirm the hardening of the mean X-ray spectrum with increasing X-ray luminosity on a sample of over 500 X-ray active stars and reveal that on average X-ray active M stars display bluer g − r colour indexes than less active ones. Although this catalogue of 2XMM-SDSS sources cannot be used directly for statistical studies, it nevertheless represents an excellent starting point to select well defined samples of X-ray-emitting objects.

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Observational Constraints on the Influence of Active Galactic Nuclei on the Evolution of Galaxies

Harrison¹

2016

Springer Theses

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How to cite: HARRISON, CHRISTOPHER,MARK (2014) Observational constraints on the inuence of active galactic nuclei on the evolution of galaxies, Durham The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source• a link is made to the metadata record in Durham E-Theses• the full-text is not changed in any wayThe full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full Durham E-Theses policy for further details. Observational constraints on the influence of active galactic nuclei on the evolution of galaxies Christopher Mark Harrison AbstractAt the centre of every massive galaxy there resides a super-massive black hole that grew during periods of active galactic nuclei (AGN) activity. Current theoretical models of galaxy evolution invoke AGN-driven galaxy-scale feedback processes (e.g., the expulsion of gas through outflows) in order to reproduce many of the fundamental properties of galaxies and the intergalactic medium. This thesis uses observations to test some of the predictions of these feedback processes. I present integral field unit observations of AGN host galaxies to trace their ionised gas kinematics. The targets are eight high-redshift (z = 1.4 −3.4) ultra-luminous infrared galaxies, that are representative of rapidly evolving distant galaxies, and sixteen z < 0.2 luminous AGN, that were selected from a parent sample of ≈24,000 sources to be representative of the overall population. In both samples I identify galaxy-wide outflows (i.e., over kiloparsec scales), calculate their properties (e.g., mass outflow rates and energetics) and show that they are broadly consistent with theoretical predictions. I find that ionised outflows are common in z < 0.2 luminous AGN and are consistently extended over kiloparsec scales (in ≥ 70% of cases). I also use far-infrared Herschel data of X-ray detected z = 1-3 AGN to test the prediction that luminous AGN shut down star formation in their host galaxies. Using stacking techniques I show that, on average, X-ray detected AGN over a wide range of luminosities (i.e., L 2−8keV ≈ 10 42−45 erg s −1 ) have star formation rates that are consistent with non-active galaxies. This may imply that luminous AGN do not impact upon the star formation in their host galaxies. Overall, this thesis demonstrates that energetic galaxy-wide outflows are prevalent in AGN host galaxies; however, it also demonstrates that we still lack direct observational evidence that luminous AGN are suppressing star formation in their host galaxies.

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Erratum: “Space Density of Optically Selected Type 2 Quasars” (2008, Aj, 136, 2373)

Cited by 178 publications

References 7 publications

On R − W1 as a Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-Ray Surveys

On R − W1 as a Diagnostic to Discover Obscured Active Galactic Nuclei in Wide-Area X-Ray Surveys

Cross-correlation of the 2XMMi catalogue with Data Release 7 of the Sloan Digital Sky Survey

Observational Constraints on the Influence of Active Galactic Nuclei on the Evolution of Galaxies

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