A Classic Type 2 QSO

Norman, Colin; Hasinger, G.; Giacconi, R.; Gilli, R.; Kewley, Lisa J.; Nonino, M.; Rosati, P.; Szokoly, G.; Tozzi, P.; Wang, Junxian; Zheng, Wei; Zirm, A.; Bergeron, J.; Gilmozzi, R.; Grogin, Norman A.; Koekemoer, Anton M.; Schreier, E.

doi:10.1086/339855

Cited by 233 publications

(276 citation statements)

References 57 publications

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“…PID 144 (z = 3.70) is a previously known, heavily obscured AGN with an X-ray absorbing column of N H ∼ (0.6−0.9) ×10 24 cm −2 (Norman et al 2002;Comastri et al 2011), located in this interval. We take this object with h/m = 1.46 as the reference and sources that have h/m larger than this object were classified as 9−20 keV excess sources.…”

Section: X-ray Colour Analysismentioning

confidence: 98%

The XMM deep survey in the CDF-S

Iwasawa

Gilli

Vignali

et al. 2012

A&A

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We present results on a search of heavily obscured active galaxies z > 1.7 using the rest-frame 9−20 keV excess for X-ray sources detected in the deep XMM-CDFS survey. Out of 176 sources selected with the conservative detection criteria (>8σ) in the first source catalogue of Ranalli et al. (in prep.), 46 objects lie in the redshift range of interest with the median redshiftz 2.5. Their typical rest-frame 10−20 keV luminosity is 10 44 erg s −1 , as observed. Among optically faint objects that lack spectroscopic redshift, four were found to be strongly absorbed X-ray sources, and the enhanced Fe K emission or absorption features in their X-ray spectra were used to obtain X-ray spectroscopic redshifts. Using the X-ray colour-colour diagram based on the rest-frame 3−5 keV, 5−9 keV, and 9−20 keV bands, seven objects were selected for their 9−20 keV excess and were found to be strongly absorbed X-ray sources with column density of N H ≥ 0.6 × 10 24 cm −2 , including two possible Compton thick sources. While they are emitting at quasar luminosity, ∼3/4 of the sample objects are found to be absorbed by N H > 10 22 cm −2 . A comparison with local AGN at the matched luminosity suggests an increasing trend of the absorbed source fraction for high-luminosity AGN towards high redshifts.

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Section: X-ray Colour Analysismentioning

confidence: 98%

The XMM deep survey in the CDF-S

Iwasawa

Gilli

Vignali

et al. 2012

A&A

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“…Figure 2 shows the Chandra spectrum of M 4835 fitted by this reflection + transmission model. -The source M 5390 is G202, the well-known, highly obscured QSO discovered by Norman et al (2002) at z = 3.7. The Chandra spectrum is consistent with the XMM one presented by Comastri et al (2011).…”

Section: X-ray and Optical Spectroscopymentioning

confidence: 99%

Faint high-redshift AGN in theChandradeep field south: the evolution of the AGN luminosity function and black hole demography

Fiore

Puccetti²,

Grazian

et al. 2011

A&A

157

172

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Context. We present detection and analysis of faint X-ray sources in the Chandra deep field south (CDFS) using the 4 Ms Chandra observation. Aims. We place constraints on active galactic nuclei (AGN) luminosity functions at z = 3-7, its cosmological evolution, and highredshift black hole and AGN demography. Methods. We use a new detection algorithm, using the entire three-dimensional data-cube (position and energy), and searching for X-ray counts at the position of high-z galaxies in the GOODS-South survey.Results. This optimized technique results in the identification of 54 AGN at z > 3, 29 of which are new detections. Applying stringent completeness criteria, we derive AGN luminosity functions in the redshift bins 3-4, 4-5, and >5.8 and for 42.75 < log L(2-10 keV) < 44.5. We combine this data with the luminous AGN luminosity functions from optical surveys and find that the evolution of the high-z, wide luminosity range luminosity function can be modeled by pure luminosity evolution with L * decreasing from 6.6 × 10 44 erg/s at z = 3 to L * = 2 × 10 44 erg/s at z = 6. We compare the high-z luminosity function with the predictions of theoretical models using galaxy interactions as AGN triggering mechanism. We find that these models are broadly able to reproduce the high-z AGN luminosity functions. Closer agreement is found when we assume a minimum dark matter halo mass for black hole formation and growth. We compare our AGN luminosity functions with galaxy mass functions to derive the high-z AGN duty cycle, using observed Eddington ratio distributions to derive black hole masses. We find that the duty cycle increases with galaxy stellar mass and redshift by a factor of 10-30 from z = 0.25 to z = 4-5. We also report the detection of a large fraction of highly obscured, Compton thick AGN at z > 3 (18 +17 −10 %). Their optical counterparts do not show any reddening and we thus conclude that the size of the X-ray absorber is likely smaller than the dust sublimation radius. We finally report the discovery of a highly star-forming galaxy at z = 3.47, arguing that its X-ray luminosity is likely dominated by stellar sources. If confirmed, this would be one of the farthest objects in which stellar sources have been detected in X-rays.

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“…In particular, the EPIC cameras have a larger field-of-view than ACIS allowing for the detection of a number of new diffuse sources just outside the Chandra field-of-view. The EPIC instruments have unprecedent high sensitivity in the hard X-ray band, and in the [5][6][7][8][9][10] keV band our dataset is comparable to the 1Ms Chandra image. Analysis of the Lockman Hole (LH; [7]) has also confirmed the idea that Xray spectroscopy of a large number of sources is very powerful with XMM-Newton.…”

Section: X-ray Observationsmentioning

confidence: 78%

“…In our field, at z >2, there are six type-2 QSOs (XID 27, 54, 57, 202, 263, 112), the most famous of which is #202, founded and described in detail by [9]. All these objects have narrow L y−α and CIV emission, HR > -0.2, and faint optical magnitudes R ≥ 24.0 [13].…”

Section: Type-2 Qsosmentioning

confidence: 99%

XMM-Newton observation of the Chandra Deep Field-South: statistical treatment of faint source spectra

Streblyanska

Bergeron

Brunner

et al. 2004

Nuclear Physics B - Proceedings Supplements

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We present first results of the X-ray spectral analysis of the 500 ksec deep survey obtained with XMM-Newton on the Chandra Deep Field South (CDFS). Statistical distributions of spectral index and intrinsic absorption are derived for a sample containing 70 sources with a count limit of 100 (flux limit in the [2-10] keV band of 8.9 ×10 −16 erg cm −2 s −1 ), of which 44 have redshift identification. We observe a separation between the type-1 and the type-2 AGN in diagnostics involving different X-ray parameters. Using the subsample with known z, we show that this separation between the AGN populations is a consequence of different absorption column densities. The two populations have the same average spectral index, Γ = 2 ± 0.1. We present integrated spectrum for the most distant type-2 QSO with strong X-ray absorption and a clear soft excess; we obtained the best fit for these objects with two different models: a scattering model and a double power law model. We also confirm a progressive hardening for the combined integrated spectra for faint objects which at first was noted by [14]. Our results shown a clear evolution of decrease of Γ with decreasing flux in the hard 2-10 keV band. However, we detect not only a regular increase of Γ for different subsamples of fluxes in comparison with Chandra results, but also an internal discrepancy of the values, if we fitted in the different energy bands.

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A Classic Type 2 QSO

Cited by 233 publications

References 57 publications

The XMM deep survey in the CDF-S

The XMM deep survey in the CDF-S

Faint high-redshift AGN in theChandradeep field south: the evolution of the AGN luminosity function and black hole demography

XMM-Newton observation of the Chandra Deep Field-South: statistical treatment of faint source spectra

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