The spectral energy distribution of the central parsecs of the nearest AGN

Prieto, M. A.; Reunanen, J.; Tristram, K.; Neumayer, Nadine; Fernández-Ontiveros, J. A.; Orienti, M.; Meisenheimer, K.

doi:10.1111/j.1365-2966.2009.15897.x

Cited by 118 publications

(182 citation statements)

References 108 publications

(165 reference statements)

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“…AGN contamination of the host galaxy light would result in an overestimate of the number of galaxies along the blue sequence. We do not expect this effect to be large, however, since the majority of the X-ray sources in our three lowest-redshift bins (z 0.4) have L X < 10 44 erg s −1 (Figure 6, left panel); hence, accretion onto the central SMBH is probably not powerful enough to significantly contaminate the host galaxy light (Prieto et al 2010). A population of starburst galaxies, whose X-ray luminosities can be as high as L X ∼ 10 42 erg s −1 , might also contaminate our blue sequence, but such X-ray-bright star-forming galaxies are more likely at higher redshift (z > 0.4; Yan et al 2010).…”

Section: Agn Host Galaxy Propertiesmentioning

confidence: 99%

THE FIELD X-RAY AGN FRACTION TOz= 0.7 FROM THECHANDRAMULTIWAVELENGTH PROJECT AND THE SLOAN DIGITAL SKY SURVEY

Haggard

Green

Anderson

et al. 2010

ApJ

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We employ the Chandra Multiwavelength Project (ChaMP) and the Sloan Digital Sky Survey (SDSS) to study the fraction of X-ray-active galaxies in the field to z = 0.7. We utilize spectroscopic redshifts from SDSS and ChaMP, as well as photometric redshifts from several SDSS catalogs, to compile a Parent sample of more than 100,000 SDSS galaxies and nearly 1600 Chandra X-ray detections. Detailed ChaMP volume completeness maps allow us to investigate the local fraction of active galactic nuclei (AGNs), defined as those objects having broadband X-ray luminosities L X (0.5-8 keV) 10 42 erg s −1 , as a function of absolute optical magnitude, X-ray luminosity, redshift, mass, and host color/morphological type. In five independent samples complete in redshift and i-band absolute magnitude, we determine the field AGN fraction to be between 0.16% ± 0.06% (for z 0.125 and −18 > M i > −20) and 3.80% ± 0.92% (for z 0.7 and M i < −23). We find excellent agreement between our ChaMP/SDSS field AGN fraction and the Chandra cluster AGN fraction, for samples restricted to similar redshift and absolute magnitude ranges: 1.19% ± 0.11% of ChaMP/SDSS field galaxies with 0.05 < z < 0.31 and absolute R-band magnitude more luminous than M R < −20 are AGNs. Our results are also broadly consistent with measures of the field AGN fraction in narrow, deep fields, though differences in the optical selection criteria, redshift coverage, and possible cosmic variance between fields introduce larger uncertainties in these comparisons.

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Section: Agn Host Galaxy Propertiesmentioning

confidence: 99%

THE FIELD X-RAY AGN FRACTION TOz= 0.7 FROM THECHANDRAMULTIWAVELENGTH PROJECT AND THE SLOAN DIGITAL SKY SURVEY

Haggard

Green

Anderson

et al. 2010

ApJ

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“…These dustdeficient quasars can be further grouped into the hot-dustdeficient (HDD) population and the warm-dust-deficient (WDD) population, possibly connected with different AGN properties. In addition, it is established that the AGN SED, including the IR part, changes from the most luminous quasars to less luminous AGNs in nearby galaxies (Ho 1999(Ho , 2008Prieto et al 2010). Hence the idea of one single IR template that applies for all kinds of AGNs, even just for quasars, is not correct.…”

Section: Does the Normal Quasar Ir Template Apply To Othermentioning

confidence: 99%

The Intrinsic Far-infrared Continua of Type-1 Quasars

Lyu

Rieke

2017

ApJ

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The range of currently proposed active galactic nucleus (AGN) far-infrared templates results in uncertainties in retrieving host galaxy information from infrared observations and also undermines constraints on the outer part of the AGN torus. We discuss how to test and reconcile these templates. Physically, the fraction of the intrinsic AGN IR-processed luminosity compared with that from the central engine should be consistent with the dust-covering factor. In addition, besides reproducing the composite spectral energy distributions (SEDs) of quasars, a correct AGN IR template combined with an accurate library of star-forming galaxy templates should be able to reproduce the IR properties of the host galaxies, such as the luminosity-dependent SED shapes and aromatic feature strengths. We develop tests based on these expected behaviors and find that the shape of the AGN intrinsic far-IR emission drops off rapidly starting at ∼20μm and can be matched by an Elvis et al.-like template with aminor modification. Despite the variations in the near-to mid-IR bands, AGNs in quasars and Seyfert galaxies have remarkably similar intrinsic far-IR SEDs at λ ∼ 20-100μm, suggesting a similar emission character of the outermost region of the circumnuclear torus. The variations of the intrinsic AGN IR SEDs among the type-1 quasar population can be explained by the changing relative strengths of four major dust components with similar characteristic temperatures, and there is evidence for compact AGN-heated dusty structures at sub-kiloparsec scales in the far-IR.

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“…However, they improve constraints on the nuclear flux by more than an order of magnitude as shown in Fig. 4, which presents the SED of the nucleus from a compilation by Prieto et al (2010).…”

Section: Limits On the Nuclear Flux In The Far-irmentioning

confidence: 99%

Mapping far-IR emission from the central kiloparsec of NGC 1097

Sandström¹,

Krause²,

Linz³

et al. 2010

A&A

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Using photometry of NGC 1097 from the Herschel PACS (Photodetector Array Camera and Spectrometer) instrument, we study the resolved properties of thermal dust continuum emission from a circumnuclear starburst ring with a radius ∼900 pc. These observations are the first to resolve the structure of a circumnuclear ring at wavelengths that probe the peak (i.e. λ ∼ 100 μm) of the dust spectral energy distribution. The ring dominates the far-infrared (far-IR) emission from the galaxy -the high angular resolution of PACS allows us to isolate the ring's contribution and we find it is responsible for 75, 60 and 55% of the total flux of NGC 1097 at 70, 100 and 160 μm, respectively. We compare the far-IR structure of the ring to what is seen at other wavelengths and identify a sequence of far-IR bright knots that correspond to those seen in radio and mid-IR images. The mid-and far-IR band ratios in the ring vary by less than ±20% azimuthally, indicating modest variation in the radiation field heating the dust on ∼600 pc scales. We explore various explanations for the azimuthal uniformity in the far-IR colors of the ring including a lack of well-defined age gradients in the young stellar cluster population, a dominant contribution to the far-IR emission from dust heated by older (>10 Myr) stars and/or a quick smoothing of local enhancements in dust temperature due to the short orbital period of the ring. Finally, we improve previous limits on the far-IR flux from the inner ∼600 pc of NGC 1097 by an order of magnitude, providing a better estimate of the total bolometric emission arising from the active galactic nucleus and its associated central starburst.

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The spectral energy distribution of the central parsecs of the nearest AGN

Cited by 118 publications

References 108 publications

THE FIELD X-RAY AGN FRACTION TOz= 0.7 FROM THECHANDRAMULTIWAVELENGTH PROJECT AND THE SLOAN DIGITAL SKY SURVEY

THE FIELD X-RAY AGN FRACTION TOz= 0.7 FROM THECHANDRAMULTIWAVELENGTH PROJECT AND THE SLOAN DIGITAL SKY SURVEY

The Intrinsic Far-infrared Continua of Type-1 Quasars

Mapping far-IR emission from the central kiloparsec of NGC 1097

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