The XMM deep survey in the CDF-S

Abstract

Nuclear obscuration plays a key role in the initial phases of AGN growth, yet not many highly obscured active galactic nuclei (AGN) are currently known beyond the local Universe, and their search is an active topic of research. The XMM-Newton survey in the Chandra Deep Field South (XMM-CDFS) aims at detecting and studying the spectral properties of a significant number of obscured and Compton-thick (N H > ∼ 10 24 cm −2 ) AGN. The large effective area of XMM-Newton in the 2-10 and 5-10 keV bands, coupled with a 3.45 Ms nominal exposure time (2.82 and 2.45 Ms after light curve cleaning for MOS and PN, respectively), allows us to build clean samples in both bands, and makes the XMM-CDFS the deepest XMM-Newton survey currently published in the 5-10 keV band. The large multi-wavelength and spectroscopic coverage of the CDFS area allows for an immediate and abundant scientific return. In this paper, we present the data reduction of the XMM-CDFS observations, the method for source detection in the 2-10 and 5-10 keV bands, and the resulting catalogues. A number of 339 and 137 sources are listed in the above bands with flux limits of 6.6 × 10 −16 and 9.5× 10 −16 erg s −1 cm −2 , respectively. The flux limits at 50% of the maximum sky coverage are 1.8× 10 −15 and 4.0× 10 −15 erg s −1 cm −2 , respectively. The catalogues have been cross-correlated with the Chandra ones: 315 and 130 identifications have been found with a likelihood-ratio method, respectively. A number of 15 new sources, previously undetected by Chandra, is found; 5 of them lie in the 4 Ms area. Redshifts, either spectroscopic or photometric, are available for ∼95% of the sources. The number counts in both bands are presented and compared to other works. The survey coverage has been calculated with the help of two extensive sets of simulations, one set per band. The simulations have been produced with a newly-developed simulator, written with the aim of the most careful reproduction of the background spatial properties. For this reason, we present a detailed decomposition of the XMM-Newton background into its components: cosmic, particle, and residual soft protons. The three components have different spatial distributions. The importance of these three components depends on the band and on the camera; the particle background is the most important one (80-90% of the background counts), followed by the soft protons (4-20%).

The NuSTAR Extragalactic Surveys: X-Ray Spectroscopic Analysis of the Bright Hard-band Selected Sample

“…Objects from the deep fields all have unique counterparts at lower energies from either the Chandra (Lehmer et al 2005;Xue et al 2011;Civano et al 2012Civano et al , 2016Goulding et al 2012) or XMM-Newton (Brusa et al 2010;Ranalli et al 2013) surveys of these same fields, with the exception of one source in the ECDF-S field (ecdfs5; this source has two possible counterparts, one at low and one at high redshift; see Table 2 and Appendix).…”

“…The prefixes of each parent catalog are cosmos for COSMOS, ecdfs for ECDF-S egs for EGS, and ser for the serendipitous survey. Ranalli et al (2013;ECDF-S). e To obtain the full NuSTAR observation IDs for the COSMOS, ECDF-S, and EGS fields, the six-digit survey identification numbers 60021, 60022, and 60023 must be prefixed, respectively.…”

The XMM deep survey in the CDF-S

“…The spectral "peculiarity" of this source came out in the search for obscured AGN at high redshift selected in the XMM-Newton observations of the Chandra Deep Field-South (XMM-CDFS) by means of restframe X-ray colors (Iwasawa et al 2012). This source is listed as number 352 in the 3 Ms XMM-Newton 2−10 keV source catalog by Ranalli et al (2013); hereafter, we refer to this source as PID352. In the following, we present the analysis of these iron features based on the whole dataset of XMM-Newton and Chandra observations, carried out over a time interval of ∼10 yr.…”

THE 31 DEG2 RELEASE OF THE STRIPE 82 X-RAY SURVEY: THE POINT SOURCE CATALOG

“…Since vignetting is a strong function of energy, we spectrally weighted the exposure maps such that the mean effective energy inputted into eexpmap is determined by assuming a power-law model where Γ=2.0 in the soft band and Γ=1.7 for the hard and full bands (see Cappelluti et al 2007). This spectral model was also used to calculate energy conversion factors (ECFs) to convert from count rates to flux, as summarized in Table 2 (for a discussion of how different assumptions for Γ affect the derived ECF, see Loaring et al 2005;Cappelluti et al 2007;Ranalli et al 2013). The exposure maps were coadded among the detectors, weighted by their ECFs.…”

“…The Chandra hard and full band fluxes from the source list were converted from the 2-7 keV and 0.5-7 keV ranges to 2-10 keV and 0.5-10 keV bands as described above. For reference, we also plot the Log N-Log S for a range of survey areas and depths: the deep, pencil-beam E-CDFS in the soft band (0.3 deg 2 ; Lehmer et al 2005) and the XMM-Newton survey of CDFS in the hard band (∼0.25 deg 2 ; Ranalli et al 2013); the moderate-area, moderate-depth Chandra COSMOSLegacy Survey (2.2 deg 2 ; Civano et al 2015;Marchesi et al 2015) in all three bands; and the wide-area 2XMMi Serendipitous Survey in the soft and hard bands (132 deg 2 ; Mateos et al 2008). The Stripe 82X Log N-Log S agrees with the reported trends from other surveys in the soft-band, the high-flux end in the hard and full bands, and with CDFS at the low-flux end (<´-2 10 14 erg s −1 ) in the hard band; discrepancies in these bands at lower fluxes (and between CDFS and COSMOS-Legacy and 2XMMi in the hard band at low fluxes) may be due to different methods for estimating survey sensitivity when generating area-flux curves and different assumed values for the power-law slope (Γ) when converting count rate to flux, and are not necessarily atypical when comparing number counts from different surveys.…”