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

Streblyanska, A.; Bergeron, J.; Brunner, H.; Finoguenov, A.; Hasinger, G.; Mainieri, V.

doi:10.1016/j.nuclphysbps.2004.04.041

Cited by 15 publications

(17 citation statements)

References 11 publications

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“…Table 7 lists the best fit spectral parameters obtained for these sources. Mainieri et al 2002;Mateos et al 2005), but there are some indications that the same effect is seen for objects detected in the 2−10 keV band (Tozzi et al 2001a;Streblyanska et al 2004). Two hypothesis have been suggested to explain it: X-ray absorption is more important at fainter fluxes or there exists a population of faint sources with intrinsically flatter continuum.…”

Section: X-ray Continuum Shape and Intrinsic Absorptionmentioning

confidence: 94%

XMM-Newton observations of the Lockman Hole IV: spectra of the brightest AGN

Mateos

Barcons

Carrera

et al. 2005

A&A

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110

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This paper presents the results of a detailed X-ray spectral analysis of a sample of 123 X-ray sources detected with XMM-Newton in the Lockman Hole field. This is the deepest observation carried out with XMM-Newton with more that 600 ks of good EPIC-pn data. We have spectra with good signal to noise (>500 source counts) for all objects down to 0.2−12 keV fluxes of ∼5 × 10 −15 erg cm −2 s −1 (flux limit of ∼6 × 10 −16 erg cm −2 s −1 in the 0.5−2 and 2−10 keV bands). At the time of the analysis, we had optical spectroscopic identifications for 60% of the sources, 46 being optical type-1 AGN and 28 optical type-2 AGN. Using a single power law model our sources' average spectral slope hardens at faint 0.5−2 keV fluxes but not at faint 2−10 keV fluxes. We have been able to explain this effect in terms of an increase in X-ray absorption at faint fluxes. We did not find in our data any evidence for the existence of a population of faint intrinsically harder sources. The average spectral slope of our sources is ∼1.9, with an intrinsic dispersion of ∼0.28. We detected X-ray absorption (F-test significance ≥95%) in 37% of the sources, ∼10% in type-1 AGN (rest-frame N H ∼ 1.6 × 10 21 −1.2 × 10 22 cm −2 ) and ∼77% (rest-frame N H ∼ 1.5 × 10 21 −4 × 10 23 cm −2 ) in type-2 AGN. Using X-ray fluxes corrected for absorption, the fraction of absorbed objects and the absorbing column density distribution did not vary with X-ray flux. Our type-1 and type-2 AGN do not appear to have different continuum shapes, but the distribution of intrinsic (rest-frame) absorbing column densities is different among both classes. A significant fraction of our type-2 AGN (5 out of 28) were found to display no substantial absorption (N H < 10 21 cm −2 ). We discuss possible interpretations to this in terms of Compton-thick AGN and intrinsic Broad Line Region properties. An emission line compatible with Fe Kα was detected in 8 sources (1 type-1 AGN, 5 type-2 AGN and 2 unidentified) with rest frame equivalent widths 120−1000 eV. However weak broad components can be easily missed in other sources by the relatively noisy data. The AGN continuum or intrinsic absorption did not depend on X-ray luminosity and/or redshift. Soft excess emission was detected in 18 objects, but only in 9 (including 4 type-1 AGN and 4 type-2 AGN) could we fit this spectral component with a black body model. The measured 0.5−2 keV luminosities of the fitted black body were not significantly different in type-1 and type-2 AGN, although the temperatures of the black body were slightly higher in type-2 AGN ( kT = 0.26 ± 0.08) than in type-1 AGN ( kT = 0.09 ± 0.01). For 9 sources (including 1 type-1 AGN and 3 type-2 AGN) a scattering model provided a better fit of the soft excess emission. We found that the integrated contribution from our sources to the X-ray background in the 2−7 keV band is softer (Γ = 1.5−1.6) than the background itself, implying that fainter sources need to be more absorbed.

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Section: X-ray Continuum Shape and Intrinsic Absorptionmentioning

confidence: 94%

XMM-Newton observations of the Lockman Hole IV: spectra of the brightest AGN

Mateos

Barcons

Carrera

et al. 2005

A&A

Self Cite

110

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“…The 2XMM serendipitous catalogue described here is complementary to "planned" XMM-Newton surveys which provide coverage of much smaller sky areas, but often with higher sensitivity, thus exploring the fainter end of the X-ray source population. The deepest such surveys, such as the Lockman Hole (Hasinger et al 2001;Brunner et al 2008) and the CDF-S (Streblyanska et al 2004), cover essentially only a single XMM-Newton field of view, have total integration times ∼300−1000 ks and reach fluxes ∼few ×10 −16 erg cm −2 s −1 , close to the confusion limit. XMM-Newton has also carried out contiguous surveys of various depths covering much larger sky areas utilising mosaics of overlapping pointed observations to achieve the required sensitivity and sky coverage.…”

Section: Introductionmentioning

confidence: 99%

The XMM-Newton serendipitous survey

Watson¹,

Schröder²,

Fyfe³

et al. 2008

A&A

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Aims. Pointed observations with XMM-Newton provide the basis for creating catalogues of X-ray sources detected serendipitously in each field. This paper describes the creation and characteristics of the 2XMM catalogue. Methods. The 2XMM catalogue has been compiled from a new processing of the XMM-Newton EPIC camera data. The main features of the processing pipeline are described in detail. Results. The catalogue, the largest ever made at X-ray wavelengths, contains 246 897 detections drawn from 3491 public XMM-Newton observations over a 7-year interval, which relate to 191 870 unique sources. The catalogue fields cover a sky area of more than 500 deg 2 . The non-overlapping sky area is ∼360 deg 2 (∼1% of the sky) as many regions of the sky are observed more than once by XMM-Newton. The catalogue probes a large sky area at the flux limit where the bulk of the objects that contribute to the X-ray background lie and provides a major resource for generating large, well-defined X-ray selected source samples, studying the X-ray source population and identifying rare object types. The main characteristics of the catalogue are presented, including its photometric and astrometric properties

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“…DC ! Ϫ17 We note that there is also weak evidence of the absorption feature in the 370 ks XMM-Newton spectrum (Streblyanska et al 2004) of CDFS 11. The XMM-Newton spectrum is significantly steeper ( ) and was obtained about one year later.…”

Section: ϫ5 ϫ4mentioning

confidence: 81%

Relativistic Outflow in CXOCDFS J033260.0-274748

Wang¹,

Wang²,

Tozzi³

et al. 2005

ApJ

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In this Letter we report the detection of a strong and extremely blueshifted X-ray absorption feature in the 1 Ms Chandra spectrum of CXOCDFS J033260.0Ϫ274748, a quasar at with 44 z p 2.579 L ∼ 4 # 10 2-10 keV ergs s Ϫ1 . The broad absorption feature at ∼6.3 keV in the observed frame can be fitted either as an absorption edge at 20.9 keV or as a broad absorption line at 22.2 keV rest frame. The absorber has to be extremely ionized with an ionization parameter , and a high column density, cm Ϫ2 . We reject the possibility 4 2 3 y ∼ 10 N 1 5 # 10 H of a statistical or instrumental artifact. The most likely interpretation is an extremely blueshifted broad absorption line or absorption edge, due to H or He-like iron in a relativistic jetlike outflow with bulk velocity of ∼0.7c-0.8c. Similar relativistic outflows have been reported in the X-ray spectra of several other AGNs in the past few years.

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

Cited by 15 publications

References 11 publications

XMM-Newton observations of the Lockman Hole IV: spectra of the brightest AGN

XMM-Newton observations of the Lockman Hole IV: spectra of the brightest AGN

The XMM-Newton serendipitous survey

Relativistic Outflow in CXOCDFS J033260.0-274748

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