Guenther Hasinger

TOWARD THE STANDARD POPULATION SYNTHESIS MODEL OF THE X-RAY BACKGROUND: EVOLUTION OF X-RAY LUMINOSITY AND ABSORPTION FUNCTIONS OF ACTIVE GALACTIC NUCLEI INCLUDING COMPTON-THICK POPULATIONS

We present the most up-to-date X-ray luminosity function (XLF) and absorption function of Active Galactic Nuclei (AGNs) over the redshift range from 0 to 5, utilizing the largest, highly complete sample ever available obtained from surveys performed with Swift/BAT, MAXI, ASCA, XMM-Newton, Chandra, and ROSAT. The combined sample, including that of the Subaru/XMM-Newton Deep Survey, consists of 4039 detections in the soft (0.5--2 keV) and/or hard (

Dissecting photometric redshift for active galactic nucleus using XMM- and Chandra-COSMOS samples

>2

The AGN contribution to mid-infrared surveys X-ray counterparts of the mid-IR sources in the Lockman Hole and HDF-N

keV) band. We utilize a maximum likelihood method to reproduce the count-rate versus redshift distribution for each survey, by taking into account the evolution of the absorbed fraction, the contribution from Compton-thick (CTK) AGNs, and broad band spectra of AGNs including reflection components from tori based on the luminosity and redshift dependent unified scheme. We find that the shape of the XLF at

On the relationship between galaxy formation and quasar evolution

z \sim 1-3

The Chandra COSMOS Legacy survey: overview and point source catalog

is significantly different from that in the local universe, for which the luminosity dependent density evolution model gives much better description than the luminosity and density evolution model. These results establish the standard population synthesis model of the X-Ray Background (XRB), which well reproduces the source counts, the observed fractions of CTK AGNs, and the spectrum of the hard XRB. The number ratio of CTK AGNs to the absorbed Compton-thin (CTN) AGNs is constrained to be

The FMOS-COSMOS Survey of Star-forming Galaxies at z ~ 1.6. I. Hα-based Star Formation Rates and Dust Extinction

\approx

Soft X-ray AGN luminosity function from ROSAT surveys - II. Table of the binned soft X-ray luminosity function

0.5--1.6 to produce the 20--50 keV XRB intensity within present uncertainties, by assuming that they follow the same evolution as CTN AGNs. The growth history of supermassive black holes is discussed based on the new AGN bolometric luminosity function.

A statistical relation between the X-ray spectral index and Eddington ratio of active galactic nuclei in deep surveys

In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for normal galaxies. We demonstrate that morphologically extended, faint X-ray sources without optical variability are more accurately described by a library of normal galaxies (corrected for emission lines) than by active galactic nucleus (AGN) dominated templates, even if these sources have AGN-like X-ray luminosities. Preselecting the library on the bases of the source properties allowed us to reach an accuracy σ_(Δz/(1+z(spec))~0.015 with a fraction of outliers of 5.8% for the entire Chandra-COSMOS sample. In addition, we release revised photometric redshifts for the 1735 optical counterparts of the XMM-detected sources over the entire 2 deg^2 of COSMOS. For 248 sources, our updated photometric redshift differs from the previous release by Δz > 0.2. These changes are predominantly due to the inclusion of newly available deep H-band photometry (H_(AB) = 24 mag). We illustrate once again the importance of a spectroscopic training sample and how an assumption about the nature of a source together, with the number and the depth of the available bands, influences the accuracy of the photometric redshifts determined for AGN. These considerations should be kept in mind when defining the observational strategies of upcoming large surveys targeting AGNs, such as eROSITA at X-ray energies and the Australian Square Kilometre Array Pathfinder Evolutionary Map of the Universe in the radio band.

An extreme [O III] emitter at z = 3.2: a low metallicity Lyman continuum source

We provide constraints on the AGN contribution to the mid-IR extragalactic background light from a correlation analysis of deep X-ray and mid-IR observations in two regions centred on the Lockman Hole and Hubble Deep Field North (HDF-N). The Lockman region, of more than 200 square arcminutes, was observed by ISOCAM and XMM-Newton to a depth of 0.3 mJy at 15 µm (resolving more than 30% of the mid-IR background). In the same area XMM-Newton reached flux limits of 1.4 × 10 −15 erg cm −2 s −1 in the 2-10 keV energy band and 2.4 × 10 −15 erg cm −2 s −1 in the 5-10 keV energy band, resolving about 80% of the 2-10 keV and 60% of the 5-10 keV backgrounds (the deepest observation in this hard band to date). Among the 76 galaxies detected by XMM-Newton, 24 show mid-IR emission, but the relative percentage of X-ray sources with mid-IR counterparts increases with the band energy: from 30% of the 0.5-2 keV sources up to 63% of the 5-10 keV sources. In contrast, only a small fraction of the mid-IR sources (around 10%) show X-ray emission within the sensitivity limits of XMM-Newton observations. The region centred on the HDF-N has been observed by ISOCAM (24 square arcminutes) to a depth of 0.05 mJy (more than 60% of the mid-IR background is resolved at this limit) and covered with a 1 Msec exposure by Chandra. In this case, 25% of the mid-IR sources are detected in the X-ray, while 30-40% of the X-ray sources show mid-IR emission. Under the assumption that all XMM sources except stars or galaxy clusters are AGN-dominated, AGNs contribute (15 ± 5)% of the total mid-IR flux in the Lockman Hole. For the HDF-N we have assumed that AGN-dominated sources are luminous X-ray sources and sources with SEDs from radio to X-ray wavelengths typical of local AGNs, in which case we find that (18 ± 7)% of the mid-IR flux are due to AGN emission. If we put together all the existing information from the deepest HDF-N data to the bright large-area sample in the ELAIS S1 region observed with BeppoSAX (for a total of 50 X-ray-mid-IR matched sources) using the median mid-IR to X-ray spectral indices as a function of the X-ray flux, we find an AGN contribution to the 15 µm background of (17 ± 2)%. Since the IR spectra of typical AGNs peak around 20 µm while starburst spectra peak at significantly longer infrared wavelengths, this figure may be considered as an upper limit to the AGN contribution to the CIRB energy density. We conclude that the population of IR luminous galaxies detected in the ISOCAM deep surveys, and the CIRB sources themselves, are mainly constituted by dust-obscured starbursts.

Evolution of the Quasar Luminosity Function over 3 < z < 5 in the COSMOS Survey Field

We compare the evolution with cosmic time of the star formation rate per comoving volume in galaxies and of the volume emissivity due to active galactic nuclei, in an attempt to understand the relationship between black hole accretion and the formation of the surrounding structure. We find an interesting similarity between the evolution rates for the total populations of galaxies and AGN, which indicates that, on average, the history of black hole accretion follows that of stellar formation in the host galaxies. Similarly, the evolution of luminous quasars parallels that of the stellar populations in massive spheroidal galaxies, in keeping with the locally established association of supermassive black holes and galactic bulges. We finally comment on our finding that high-luminosity, high-mass systems evolve on a shorter cosmic time-scale than lower mass ones; to explain this, theories of structure formation based on the gravitational collapse of dark matter haloes must be complemented with a detailed description of the dynamical processes in the baryonic component, which dominate the formation and evolution in high-density environments.