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A survey of UV-excess AGNs in the South Galactic Pole - A sample for the analysis of the QSO clustering

Spectra, position, magnitudes and colors are presented for 485 faint () emission line objects selected with the ultraviolet-excess (UVX) criterion on a area of 24.6 deg2 in the South Galactic Pole. The objects were selected from the analysis of pixel-to-pixel stacking of COSMOS scans of UKST U J and R plates. The candidates were observed with the Meudon-ESO Fiber Optics System...

The assembly of ‘normal’ galaxies at z ∼ 7 probed by ALMA

We report new deep observations obtained with the Atacama Large Millimetre Array (ALMA) aimed at investigating the [C ii]158 μm line and continuum emission in three spectroscopically confirmed Lyman break galaxies at 6.8 < z ≤ 7.1, i.e. well within the re-ionization epoch. With star formation rates of SFR ∼ 5–15M⊙ yr− 1 these systems are much more representative of the high-z...

Contamination on Lyman continuum emission at z ≳ 3: implication on the ionizing radiation evolution*

We investigate the possibility of contamination by lower redshift interlopers in the measure of the ionizing radiation escaping from high-redshift galaxies. Taking advantage of the new ultradeep Very Large Telescope/Visible Multiobject Spectrograph U-band number counts in the Great Observatories Origins Deep Survey (GOODS)-South field, we calculate the expected probability of...

Faint AGNs at z > 4 in the CANDELS GOODS-S field: looking for contributors to the reionization of the Universe

Context. Establishing the number of faint active galactic nuclei (AGNs) at z = 4−6 is crucial to understanding their cosmological importance as main contributors to the reionization of the Universe.Aims. In order to derive the AGN contribution to the cosmological ionizing emissivity we have selected faint AGN candidates at z> 4 in the CANDELS GOODS-South field, which is one of...

High-resolution spectroscopy of the 3D cosmic web with close QSO groups*

We study the 3D distribution of matter at z∼ 2 using high-resolution spectra of quasi-stellar object (QSO) pairs and simulated spectra drawn from cosmological hydrodynamical simulations. We present a sample of 15 QSOs, corresponding to 21 baselines of angular separations evenly distributed between ∼1 and 14 arcmin, observed with the Ultraviolet and Visual Echelle Spectrograph...

Cosmic evolution of the C iv in high-resolution hydrodynamic simulations

We investigate the properties of triply ionized carbon (C iv) in the intergalactic medium (IGM) using a set of high resolution and large box size cosmological hydrodynamic simulations of a Lambda cold dark matter (ΛCDM) model. We rely on a modification of the publicly available TreeSPH code gadget-2 that self-consistently follows the metal enrichment mechanism by means of a...

Tracing the gas at redshift 1.7–3.5 with the Lyα forest: the FLO approach*

We present FLO (From Lines to Overdensities), a new technique to reconstruct the hydrogen density field for the Lyα forest lines observed in high-resolution QSO spectra. The method is based on the hypothesis that the Lyα lines arise in the low to intermediate density intergalactic gas and that the Jeans length is the typical size of the Lyα absorbers. The reliability of FLO is...

The quasar proximity effect at redshift 〈z〉≃ 2.6 with the From Lines to Overdensities approach*

We revisit the proximity effect produced by quasars (QSOs) at redshifts 2.1–3.3 applying the From Lines to Overdensities (FLO) approach to a sample of ∼6300 Lyα lines fitted in 21 high resolution, high signal-to-noise spectra. This new technique allows to recover the hydrogen-density field from the H i column densities of the lines in the Lyα forest, on the basis of simple...

The blue UV slopes of z  ~  4 Lyman break galaxies: implications for the corrected star formation rate density

Context. Study of the dust extinction in high-redshift galaxies is fundamental to obtaining an estimate of the corrected star formation rate density (SFRD) and to put constraints on galaxy evolution models.Aims. We plan to analyse dust extinction in Lyman break galaxies (LBGs) by introducing a new and more reliable approach to their selection and to the characterization of their...

The blue UV slopes of z  ~  4 Lyman break galaxies: implications for the corrected star formation rate density

Context. Study of the dust extinction in high-redshift galaxies is fundamental to obtaining an estimate of the corrected star formation rate density (SFRD) and to put constraints on galaxy evolution models.Aims. We plan to analyse dust extinction in Lyman break galaxies (LBGs) by introducing a new and more reliable approach to their selection and to the characterization of their...

The unusual N IV] -emitter galaxy GDS J033218.92-275302.7: star formation or AGN-driven winds from a massive galaxy at z = 5.56

Aims. We investigate the nature of the source GDS J033218.92-275302.7 at redshift ~5.56.Methods. The spectral energy distribution of the source is well-sampled by 16 bands photometry from UV-optical (HST and VLT), near infrared, near infrared (VLT) to mid-infrared (Spitzer). The detection of a signal in the mid-infrared Spitzer/IRAC bands 5.8, 8.0 μm – where the nebular emission...

On the radio properties of the highest redshift quasars

We present deep radio observations of the most distant complete quasar sample drawn from the Sloan Digital Sky Survey. Combining our new data with those from literature, we obtain a sample which is ∼100 per cent complete down to S1.4 GHz= 60 μJy over the redshift range 3.8 ≤z≤ 5. The fraction of radio detections is relatively high (∼43 per cent), similar to what observed locally...

High matter density peaks from UVES observations of QSO pairs: Correlation properties and chemical abundances

. , & Miralda-Escude´ , J. 1996 , ApJ, 457 , L57 Kim , T.-S., Cristiani , S. , & D'Odorico , S. 2001 , A &A, 373 , 757 de Kool , M. , Arav , N. , Becker , R. H. , et al. 2001 , ApJ, 548 , 609 Le Brun , V

Tomography of the intergalactic medium with Lyα forests in close QSO pairs*

We study the three-dimensional distribution of non-virialized matter at z∼ 2 using high-resolution spectra of quasi-stellar object (QSO) pairs and simulated spectra drawn from cosmological hydrodynamical simulations. We have collected the largest sample of QSO pairs ever observed with Ultraviolet and Visual Echelle Spectrograph (UVES) at the European Southern Observatory-Very...

The red and blue galaxy populations in the GOODS field: evidence for an excess of red dwarfs

Aims. We study the evolution of the galaxy population up to as a function of its colour properties. In particular, luminosity functions and luminosity densities were derived as a function of redshift for the blue/late and red/early populations.Methods.We use data from the GOODS-MUSIC catalogue, which have typical magnitude limits and for most of the sample. About 8% of the...

The great observatories origins deep survey - VLT/VIMOS spectroscopy in the GOODS-south field

Aims. We present the first results from the VIsible Multiobject Spectrograph (VIMOS) ESO/GOODS program of spectroscopy for faint galaxies in the Chandra Deep Field South (CDF-S). This program complements the FORS2 ESO/GOODS campaign.Methods. All 3312 spectra were obtained in service mode with VIMOS at the ESO/VLT UT3. The VIMOS LR-Blue and MR grisms were used to cover different...

The power spectrum of the flux distribution in the Lyman α forest of a large sample of UVES QSO absorption spectra (LUQAS)⋆

Kaiser N. , 1987 , MNRAS, 227 , 1 Kaiser N. , Peacock J. A. , 1991 , ApJ, 379 , 482 Lomb N. R. , 1976 , Ap&SS, 39 , 447 Kim T.-S. , Cristiani , S., D'Dodorico S. , 2001 , A&A, 373 , 757 Kim T.-S

Probing the evolution of the near-infrared luminosity function of galaxies to z≃ 3 in the Hubble Deep Field-South

We present the rest-frame Js- and Ks-band luminosity function (LF) of a sample of about 300 galaxies selected in the Hubble Deep Field-South (HDF-S) at Ks≤ 23 (Vega). We use calibrated photometric redshift together with spectroscopic redshift for 25 per cent of the sample. The accuracy reached in the photometric redshift estimate is 0.06 (rms) and the fraction of outliers is 1...

The physical properties of the Lyα forest at z > 1.5

Combining a new, increased data set of eight quasi-stellar objects (QSOs) covering the Lyα forest at redshifts 1.5 < z < 3.6 from VLT/UVES observations with previously published results, we have investigated the properties of the Lyα forest at 1.5 < z <4. With the six QSOs covering the Lyα forest at 1.5 < z < 2.5, we have extended previous studies in this redshift range. In...

A comprehensive study of large-scale structures in the GOODS-SOUTH field up to 2.5

Arnouts, S. , Cristiani , S. , Moscardini , L. , et al. 1999 , MNRAS, 310 , 540 Bahcall, N. A. 1999 , in Formation of Structure in the Universe, ed. A. Dekel , & J. P. Ostriker , 135 Balogh , M. L. , Baldry