E. Piconcelli

The XMM-Newton view of PG quasars I. X-ray continuum and absorption

We present results of a systematic analysis of the XMM-Newton spectra of 40 quasars (QSOs) (z ≤ 1.72) from the Palomar-Green (PG) Bright Quasar Survey sample (MB < −23). The sample includes 35 radio-quiet quasars (RQQs) and 5 radio-loud quasars (RLQs). The analysis of the spectra above 2 keV reveals that the hard X-ray continuum emission can be modeled with a power law component with � Γ2−12 keV� = 1.89 ± 0.11 and � Γ2−12 keV� = 1.63 +0.02 −0.01 for the RQQs and RLQs, respectively. Below 2 keV, a strong, broad excess is present in most QSO spectra. This feature has been fitted with four different models assuming several physical scenarios. All tested models (blackbody, multicolor blackbody, bremsstrahlung and power law) satisfactorily fitted the majority of the spectra. However, none of them is able to provide an adequate parameterization for the soft excess emission in all QSOs, indicating the absence of a universal shape for this spectral feature. An additional cold absorption component was required only in three sources. On the other hand, as recently pointed out by Porquet et al. (2004) for a smaller sample of PG QSOs, warm absorber features are present in 50% of the QSO spectra in contrast with their rare occurrence (∼5−10%) in previous studies. The XMM-Newton view of optically selected bright QSOs therefore suggests that there are no significant differences in the X-ray spectral properties compared with those of the low-luminosity Seyfert 1 galaxies. Properties of the Fe Kα emission lines are presented in a companion paper.

Evidence of strong quasar feedback in the early universe

Most theoretical models invoke quasar driven outflows to que nch star formation in massive galaxies, and this feedback mechanism is required to account for the population of old and passive galaxies observed in the local universe. The discovery of massive, old and passive galaxies at z∼2, implies that such quasar feedback onto the host galaxy must have been at work very early on, close to the reionization epoch. We have observed the [CII]158µm transition in SDSSJ114816.64+525150.3 that, at z=6.4189, is one of the most distant quasars known. We detect broad wings of the line tracing a quasar-driven massive outflow. This is the most distant massive outflow ever detected and is likely tracing t he long sought quasar feedback, already at work in the early Universe. The outflow is marginal ly resolved on scales of∼16 kpc, implying that the outflow can really a ffect the whole galaxy, as required by quasar feedback models. The inferred outflow rate, ˙ M > 3500 M⊙ yr −1 , is the highest ever found. At this rate the outflow can clean the gas in the host galaxy, and therefore quench star formation, in a few million years.

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

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 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.

Evidence for a multizone warm absorber in the XMM–Newton spectrum of Markarian 304

We present a XMM-Newton observation of Markarian 304, a Seyfert 1 galaxy at z = 0.066. The EPIC data show that MKN 304 is affected by heavy (N H 10 23 cm -2 ) obscuration arising from ionized gas. A two-phase warm absorber provides an adequate parametrization of this gas. The ionization parameter of the two components is ξ 6 erg cm -2 s -1 and ξ 90 erg cm -2 s -1 , respectively. The observed continuum photon index (r 1.9) is typical for Seyfert 1 galaxies. Two significant emission lines are detected at 0.57 keV and 6.4 keV, respectively. The former is mostly likely due to He-like oxygen triplet emission arising from an ionized plasma (maybe the warm absorber itself). The latter is due to fluorescent emission of K-shell iron in a low-ionization state (Fe i-xv). The upper limit for the line width of σ Kα < 0.18 keV most likely rules out an origin in the inner parts of the accretion disc. Interestingly, the strength of such line is consistent with the possibility that the emission is produced in the warm absorber itself. However, a substantial contribution from the torus is plausible too. We have also found a weak (4 per cent of the primary continuum) soft excess emission component. The presence of this excess could be explained by either emission/scattering from a warm gas or partial covering, or a combination of them.

Chandra unveils a binary Active Galactic Nucleus in Mrk 463

We analyse Chandra, XMM‐Newton and Hubble Space Telescope (HST) data of the doublenucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk 463. The Chandra detection of two luminous (L2‐10 keV = 1.5 × 10 43 and 3.8 × 10 42 erg cm −2 s −1 ), unresolved nuclei in Mrk 463 indicates that this galaxy hosts a binary active galactic nucleus (AGN), with a projected separation of � 3.8 kpc (3.83 ± 0.01 arcsec). While the East nucleus was already known to be a type 2 Seyfert (and this is further confirmed by our Chandra detection of a neutral iron line), this is the first unambiguous evidence in favour of the AGN nature of the West nucleus. Mrk 463 is therefore the clearest case so far for a binary AGN, after NGC 6240.

The multi-phase winds of Markarian 231: from the hot, nuclear, ultra-fast wind to the galaxy-scale, molecular outflow

Mrk 231 is a nearby ultra-luminous IR galaxy exhibiting a kpc-scale, multi-phase AGN-driven outflow. This galaxy represents the best target to investigate in detail the morphology and energetics of powerful outflows, as well as their still poorly-understood expansion mechanism and impact on the host galaxy. In this work, we present the best sensitivity and angular resolution maps of the molecular disk and outflow of Mrk 231, as traced by CO(2−1) and (3−2) observations obtained with the IRAM/PdBI. In addition, we analyze archival deep Chandra and NuSTAR X-ray observations. We use this unprecedented combination of multi-wavelength data sets to constrain the physical properties of both the molecular disk and outflow, the presence of a highly-ionized ultra-fast nuclear wind, and their connection. The molecular CO(2−1) outflow has a size of ~1 kpc, and extends in all directions around the nucleus, being more prominent along the south-west to north-east direction, suggesting a wide-angle biconical geometry. The maximum projected velocity of the outflow is nearly constant out to ~1 kpc, thus implying that the density of the outflowing material must decrease from the nucleus outwards as ~r-2. This suggests that either a large part of the gas leaves the flow during its expansion or that the bulk of the outflow has not yet reached out to ~1 kpc, thus implying a limit on its age of ~1 Myr. Mapping the mass and energy rates of the molecular outflow yields OF = [500−1000] M⊙ yr-1 and Ėkin,OF = [7−10] × 10^(43) erg s^(-1). The total kinetic energy of the outflow is Ekin,OF is of the same order of the total energy of the molecular disk, Edisk. Remarkably, our analysis of the X-ray data reveals a nuclear ultra-fast outflow (UFO) with velocity −20 000 km s^(-1), UFO = [0.3−2.1] M_⊙ yr^(-1), and momentum load UFO/ rad = [0.2−1.6]. We find Ėkin,UFO ~ Ėkin,OF as predicted for outflows undergoing an energy conserving expansion. This suggests that most of the UFO kinetic energy is transferred to mechanical energy of the kpc-scale outflow, strongly supporting that the energy released during accretion of matter onto super-massive black holes is the ultimate driver of giant massive outflows. The momentum flux OF derived for the large scale outflows in Mrk 231 enables us to estimate a momentum boost OF/ UFO ≈ [30−60]. The ratios Ėkin,UFO/Lbol,AGN = [1−5] % and Ėkin,OF/Lbol,AGN = [1−3] % agree with the requirements of the most popular models of AGN feedback.

The XMM-Newton and BeppoSAX view of the Ultra Luminous Infrared Galaxy MKN 231

We discuss XMM-Newton and BeppoSAX observations of MKN 231, the lowest-redshift Broad Absorption Line (BAL) QSO known so far and one of the best-studied Ultra Luminous Infrared Galaxies. By combining the XMM-Newton spectral resolution and the high-energy bandpass of BeppoSAX we have been able to study in more detail than previ- ously possible its 0.2-50 keV spectral properties. The BeppoSAX PDS data unveiled, for the first time, a highly absorbed (NH ∼ 2 × 10 24 cm −2 ) power-law component. We find that: a) below 10 keV we are seeing only reprocessed radiation through reflection and/or scattering; b) the intrinsic 2-10 keV luminosity of MKN 231 is 1 +1.0 −0.5 × 10

X-shooter reveals powerful outflows in z ∼ 1.5 X-ray selected obscured quasi-stellar objects

We present X-shooter at the Vewry Large Telescope observations of a sample of 10 luminous, X-ray obscured QSOs at z

How Complex is the Obscuration in Active Galactic Nuclei? New Clues from the Suzaku Monitoring of the X-Ray Absorbers in NGC 7582

\sim1.5

Very extended cold gas, star formation and outflows in the halo of a bright quasar at z > 6

from the XMM-COSMOS survey, expected to be caught in the transitioning phase from starburst to active galactic nucleus (AGN)-dominated systems. The main selection criterion is X-ray detection at bright fluxes (L