The Vimos VLT Deep Survey: Global properties of 20000 galaxies in the I_AB<=22.5 WIDE survey
B. Garilli, O. Le Fèvre, L. Guzzo, D. Maccagni, V. Le Brun, S. de la Torre, B. Meneux, L. Tresse, P. Franzetti, G. Zamorani, A. Zanichelli, L. Gregorini, D. Ver… 展开作者
B. Garilli, O. Le Fèvre, L. Guzzo, D. Maccagni, V. Le Brun, S. de la Torre, B. Meneux, L. Tresse, P. Franzetti, G. Zamorani, A. Zanichelli, L. Gregorini, D. Vergani, D. Bottini, R. Scaramella, M. Scodeggio, G. Vettolani, C. Adami, S. Arnouts, S. Bardelli, M. Bolzonella, A. Cappi, S. Charlot, P. Ciliegi, T. Contini, S. Foucaud, I. Gavignaud, O. Ilbert, A. Iovino, F. Lamareille, H. J. McCracken, B. Marano, C. Marinoni, A. Mazure, R. Merighi, S. Paltani, R. Pellò, A. Pollo, L. Pozzetti, M. Radovich, E. Zucca, J. Blaizot, A. Bongiorno, O. Cucciati, Y. Mellier, C. Moreau, L. Paioro
备注：
Accepted for publication on Astronomy & Astrophysics
The VVDS-Wide survey has been designed with the general aim of tracing the large-scale distribution of galaxies at z~1 on comoving scales reaching ~100Mpc/h, while providing a good control of cosmic variance over areas as large as a few square degrees. This is achieved by measuring redshifts with VIMOS at the ESO VLT to a limiting magnitude I_AB=22.5, targeting four independent fields with size up to 4 sq.deg. each. The whole survey covers 8.6 sq.deg., here we present the general properties of the current redshift sample. This includes 32734 spectra in the four regions (19977 galaxies, 304 type I AGNs, and 9913 stars), covering a total area of 6.1 sq.deg, with a sampling rate of 22 to 24%. The redshift success rate is above 90% independently of magnitude. It is the currently largest area coverage among redshift surveys reaching z~1. We give the mean N(z) distribution averaged over 6.1 sq.deg. Comparing galaxy densities from the four fields shows that in a redshift bin Deltaz=0.1 at z~1 one still has factor-of-two variations over areas as large as ~0.25 sq.deg. This level of cosmic variance agrees with that obtained by integrating the galaxy two-point correlation function estimated from the F22 field alone, and is also in fairly good statistical agreement with that predicted by the Millennium mocks. The variance estimated over the survey fields shows explicitly how clustering results from deep surveys of even ~1 sq.deg. size should be interpreted with caution. This paper accompanies the public release of the first 18143 redshifts of the VVDS-Wide survey from the 4 sq.deg. contiguous area of the F22 field at RA=22h, publicly available at http://cencosw.oamp.fr
The VIMOS VLT Deep Survey is a unique I-selected spectroscopic sample to study galaxies all the way from z=5 to z=0. We recapitulate the first results about the evolution of the galaxy populations as a function of type, morphology, environment and luminosity.
We studied the bulge and the disk kinematic of the giant Low Surface Brightness (LSB) galaxy ESO 323-G064 in order to investigate its dynamics and its Dark Matter (DM) content. We observed the galaxy with the integral field spectroscopy (VLT/VIMOS, in IFU configuration). Results for the gaseous kinematics (bulge and disk) and stellar kinematics (bulge) are presented, together with a Jeans model for the stellar bulge kinematics.
VIMOS (VIsible Multi-Object Spectrograph) is a multi-object imaging spectrograph installed at the VLT (Very large Telescope) at the ESO (European Southern Observatory) Paranal Observatory, especially suited for survey work. VIMOS is characterized by its very high multiplexing factor: it is possible to take up to 800 spectra with 10 arcsec long slits in a single exposure. To fully exploit its multiplexing potential, we designed and implemented a dedicated software tool: the VIMOS Mask Preparation Software (VMMPS), which allows the astronomer to select the objects to be spectroscopically observe…
We have investigated the dependence of galaxy clustering on their stellar mass at z~1, using the data from the VIMOS-VLT Deep Survey (VVDS). We have measured the projected two-point correlation function of galaxies, wp(rp) for a set of stellar mass selected samples at an effective redshift <z>=0.85. We have control and quantify all effects on galaxy clustering due to the incompleteness of our low mass samples. We find that more massive galaxies are more clustered. When compared to similar results at z~0.1 in the SDSS, we observed no evolution of the projected correlation function for massive g…
We present the first results of the VIsible Multiobject Spectrograph (VIMOS) ESO/GOODS program of spectroscopy of faint galaxies in the Chandra Deep Field South (CDF-S). The program complements the FORS2 ESO/GOODS campaign. 3312 spectra have been obtained in service mode with VIMOS at the ESO/VLT UT3. The VIMOS LR-Blue and MR grisms have been used to cover different redshift ranges. Galaxies at 1.8 < z < 3.5 have been observed in the GOODS VIMOS-LR-Blue campaign. Galaxies at z < 1 and Lyman Break Galaxies at z > 3.5 have been observed in the VIMOS MR survey. Here we report results for the firs…
The VIRMOS consortium of French and Italian Institutes (PI: O. Le Fevre, co-PI: G. Vettolani) is manufacturing two wide field imaging multi-object spectrographs for the European Southern Observatory Very Large Telescope (VLT), with emphasis on the ability to carry over spectroscopic surveys of large numbers of sources: the VIsible Multi-Object Spectrograph, VIMOS, and the Near InfraRed Multi-Object Spectrograph, NIRMOS. There are 52 motors to be controlled in parallel in the spectrograph, making VIMOS a complex machine to be handled. This paper will focus on the description of the control syst…
We have investigated the dependence of galaxy clustering on their intrinsic luminosities at z ~ 1, using the data from the First Epoch VIMOS-VLT Deep Survey (VVDS). We have measured the projected two-point correlation function of galaxies, w_p(r_p), for a set of volume-limited samples at an effective redshift <z>=0.9 and median absolute magnitude -19.6< M_B < -21.3. We find that the clustering strength is rising around M_B^*, apparently with a sharper turn than observed at low redshifts. The slope of the correlation function is observed to steepen significantly from γ=1.6^{+0.1}_{-0.1} to γ=2.…
We have used the Vimos VLT Deep Survey in combination with other spectroscopic, photometric and X-ray surveys from literature to detect several galaxy structures in the Chandra Deep Field South (CDFS). Both a friend-of-friend based algorithm applied to the spectroscopic redshift catalog and an adaptative kernel galaxy density and colour maps correlated with photometric redshift estimates have been used. We mainly detect a chain-like structure at z=0.66 and two massive groups at z=0.735 and 1.098 showing signs of ongoing collapse. We also detect two galaxy walls at z=0.66 and at z=0.735 (extrem…
{This paper presents the VIMOS VLT Deep Survey around the Chandra Deep Field South (CDFS). We have measured 1599 new redshifts with VIMOS on the European Observatory Very Large Telescope - UT3, in an area 21x21.6 arcmin^2, including 784 redshifts in the Hubble Space Telescope - Advanced Camera for Surveys GOODS area. 30% of all objects with I_AB=24 have been observed independently of magnitude, indicating that the sample is purely magnitude limited. We have reached an unprecedented completeness level of 88% in terms of the ratio of secure measurements vs. observed objects, while 95% of all obj…
We have reconstructed the three-dimensional density fluctuation maps to z ~ 1.5 using the distribution of galaxies observed in the VVDS-Deep survey. We use this overdensity field to measure the evolution of the probability distribution function and its lower-order moments over the redshift interval 0.7<z<1.5. We apply a self-consistent reconstruction scheme which includes a complete non-linear description of galaxy biasing and which has been throughly tested on realistic mock samples. We find that the variance and skewness of the galaxy distribution evolve over this redshift interval in a way …
We present: 1) a kinematic and morphological study of the giant Lya nebula associated with the radio galaxy MRC2104-242 (z = 2.49) based on integral field spectroscopic VIMOS data from VLT; 2) a photometric study of the host (proto?) galaxy based on Spitzer Space Telescope data. The galaxy appears to be embedded in a giant (>120 kpc) gas reservoir that surrounds it completely. The kinematic properties of the nebula suggest that it is a rotating structure, which would imply a lower limit to the dynamical mass of ~3 x 1e11 Msun. An alternate scenario is that the gas is infalling. Such a process …
The VIMOS VLT Deep Survey (VVDS) is underway to study the evolution of galaxies, large scale structures and AGNs, from the measurement of more than 100000 spectra of faint objects. We present here the results from the first epoch observations of more than 20000 spectra. The main challenge of the program, the redshift measurements, is described, in particular entering the ``redshift desert'' in the range $1.5<z<3$ for which only very weak features are observed in the observed wavelength range. The redshift distribution of a magnitude limited sample brighter than $I_{AB}=24$ is presented for the…
(Ultra)Luminous Infrared Galaxies [(U)LIRGs] are much more numerous at cosmological distances than locally, and are likely precursors of elliptical galaxies. Our goal is to carry out an integral field spectroscopic survey of a representative sample of low redshift (z < 0.26) (U)LIRGs, covering different morphologies from spirals to mergers over the entire infrared luminosity range. The present study is based on optical IFS obtained with the VIMOS instrument on the VLT. The first results of this survey are presented here with the study of two galaxies representative of the two major morphologic…
The morphological and spectroscopic properties of the giant (>60 kpc) Ly-alpha nebulae associated with three radio galaxies at z~2.5 (MRC 1558-003, MRC 2025-218 and MRC 0140-257) have been investigated using integral field spectroscopic data obtained with VIMOS on VLT. The morphologies are varied. The nebula of one source has a centrally peaked, rounded appearance. In the other two objects, it consists of two spatial components. The three nebulae are aligned with the radio axis within <30 deg. The total Ly-alpha luminosities are in the range (0.3-3.4) x 1e44 erg s-1. The Ly-alpha spectral prof…
We examine the dynamics structure of the rich cluster A1689, combining VLT/VIMOS spectroscopy with Subaru/Suprime-Cam imaging. The radial velocity distribution of $\sim 500$ cluster members is bounded by a pair of clearly defined velocity caustics, with a maximum amplitude of $\sim|4000|$ km/s at $\simeq$ 300 h$^{-1}$ kpc, beyond which the amplitude steadily declines, approaching zero velocity at a limiting radius of $\sim$ 2 h$^{-1}$ Mpc. We derive the 3D velocity anisotropy and galaxy number density profiles using a model-independent method to solve the Jeans equation, simultaneously incorpo…
VIMOS is a wide-field imager and spectrograph mounted on UT3 at the VLT, whose FOV consists of four 7'x8' quadrants. Here we present the measurements of total transmission profiles -- i.e. the throughput of telescope + instrument -- for the broad band filters U, B, V, R, I, and z for each of its four quadrants. Those measurements can also be downloaded from the public VIMOS web-page. The transmission profiles are compared with previous estimates from the VIMOS consortium.
This paper presents the ``First Epoch'' sample from the VIMOS VLT Deep Survey (VVDS). The VVDS goals, observations, data reduction with VIPGI, and redshift measurement with KBRED are discussed. Data have been obtained with the VIsible Multi Object Spectrograph (VIMOS) on the ESO-VLT UT3, allowing to observe ~600 slits simultaneously at R~230. A total of 11564 objects have been observed in the VVDS-02h and VVDS-CDFS Deep fields over a total area of 0.61deg^2, selected solely on the basis of apparent magnitude 17.5 <=I_{AB} <=24. The VVDS covers the redshift range 0 < z <= 5. It is successfully …
Aims:We have studied the bulge and the disk kinematics of the giant low surface brightness galaxy ESO 323-G064 in order to investigate its dynamical properties and the radial mass profile of the dark matter (DM) halo. Methods:We observed the galaxy with integral field spectroscopy (VLT/VIMOS, in IFU configuration), measured the positions of the ionized gas by fitting Gaussian functions to the O[III] and Hbeta emission lines, and fit stellar templates to the galaxy spectra to determine velocity and velocity dispersions. We modeled the stellar kinematics in the bulge with spherical isotropic Jea…
We derive the mass-metallicity relation of star-forming galaxies up to $z\sim0.9$, using data from the VIMOS VLT Deep Survey. Automatic measurement of emission-line fluxes and equivalent widths have been performed on the full spectroscopic sample. This sample is divided into two sub-samples depending on the apparent magnitude selection: wide ($I_{\mathrm{AB}}<22.5$) and deep $I_{\mathrm{AB}}<24$). These two samples span two different ranges of stellar masses. Emission-line galaxies have been separated into star-forming galaxies and active galactic nuclei using emission line ratios. For the sta…
We investigate the evolution of the galaxy luminosity function from the VIMOS-VLT Deep Survey (VVDS) from the present to z=2 in five (U, B, V, R and I) rest-frame band-passes. We use the first epoch VVDS deep sample of 11,034 spectra selected at 17.5 <= I_{AB} <= 24.0, on which we apply the Algorithm for Luminosity Function (ALF), described in this paper. We observe a substantial evolution with redshift of the global luminosity functions in all bands. From z=0.05 to z=2, we measure a brightening of the characteristic magnitude M* included in the magnitude range 1.8-2.5, 1.7-2.4, 1.2-1.9, 1.1-1…
We investigate the dependence of galaxy clustering on the galaxy intrinsic luminosity at high redshift, using the data from the First Epoch VIMOS-VLT Deep Survey (VVDS). The size (6530 galaxies) and depth (I_{AB}<24) of the survey allows us to measure the projected two-point correlation function of galaxies, w_p(r_p) for a set of volume-limited samples up to an effective redshift <z>=0.9 and median absolute magnitude -19.6< M_B < -21.3. Fitting w_p(r_p) with a single power-law model for the real-space correlation function xi(r)=(r/r_0)^{-gamma}, we measure the relationship of the correlation l…
AIMS. We present a new Ks-band survey that represents a significant extension to the previous wide-field Ks-band imaging survey within the 0226-04 field of the VIMOS-VLT deep survey (VVDS). The new data add ~ 458 arcmin^2 to the previous imaging program, thus allowing us to cover a total contiguous area of ~ 600 arcmin^2 within this field. METHODS. Sources are identified both directly on the final K-band mosaic image and on the corresponding, deep chi^2-g'r'i' image from the CFHT Legacy Survey in order to reduce contamination while ensuring us the compilation of a truly K-selected catalogue do…
The VIMOS-VLT Deep Survey (VVDS) currently offers a unique combination of depth, angular size and number of measured galaxies among surveys of the distant Universe: ~ 11,000 spectra over 0.5 deg2 to I_{AB}=24 (VVDS-Deep), 35,000 spectra over ~ 7 deg2 to I_{AB}=22.5 (VVDS-Wide). The current ``First Epoch'' data from VVDS-Deep already allow investigations of galaxy clustering and its dependence on galaxy properties to be extended to redshifts ~1.2-1.5, in addition to measuring accurately evolution in the properties of galaxies up to z~4. This paper concentrates on the main results obtained so fa…
zCOSMOS is a large redshift survey that is being undertaken in the COSMOS field using 600 hours of observation with the VIMOS spectrograph on the 8-m VLT. The survey is designed to characterise the environments of COSMOS galaxies from the 100 kpc scales of galaxy groups up to the 100 Mpc scale of the cosmic web and to produce diagnostic information on galaxies and active galactic nuclei. The zCOSMOS survey consists of two parts: (a) zCOSMOS-bright, a magnitude-limited I-band IAB < 22.5 sample of about 20,000 galaxies with 0.1 < z < 1.2 covering the whole 1.7 deg2 COSMOS ACS field and designed …
We present the first measurements of the Probability Distribution Function (PDF) of galaxy fluctuations in the VIMOS-VLT Deep Survey (VVDS) cone, covering 0.4x0.4 deg between 0.4<z<1.5. The second moment of the PDF, i.e. the rms fluctuations of the galaxy density field, is with good approximation constant over the full redshift baseline investigated: we find that, in redshift space, sigma_8 for galaxies brighter than M=-20+5log h has a mean value of 0.94\pm0.07 in the redshift interval 0.7<z<1.5. The third moment, i.e. the skewness, increases with cosmic time: we find that the probability of h…
We are presenting in this paper a detailed account of the methods used to compute the three-dimensional two-point galaxy correlation function in the VIMOS-VLT deep survey (VVDS). We investigate how instrumental selection effects and observational biases affect the measurements and identify the methods to correct them. We quantify the accuracy of our correction method using an ensemble of fifty mock galaxy surveys generated with the GalICS semi-analytic model of galaxy formation which incorporate the same selection biases and tiling strategy as the real data does. We demonstrate that we are abl…
In this paper we present the optical and near-infrared identifications of the 1054 radio sources detected in the 20cm deep radio survey down to a 5sigma flux limit of about 80 microJy obtained with the VLA in the VIMOS VLT Deep Survey VVDS-02h deep field. Using U,B,V,R,I and K data, we identified 718 radio sources (~74% of the whole sample). The photometric redshift analysis shows that, in each magnitude bin, the radio sample has a higher median photometric redshift than the whole optical sample, while the median (V-I) color of the radio sources is redder than the median color of the whole opt…
We measure the evolution of the galaxy Luminosity Function as a function of large-scale environment up to z=1.5 from the VIMOS-VLT Deep Survey (VVDS) first epoch data. The 3D galaxy density field is reconstructed using a sample of 6582 galaxies with 17.5 < I_{AB} < 24 and measured spectroscopic redshifts. We split the sample in four redshift bins up to z=1.5 and in under-dense and over-dense environments according to the average density contrast δ=0. There is a strong dependence of the Luminosity Function (LF) with large-scale environment up to z=1.2: the LF shape is observed to have a steeper…
Aims. We present a continuation of our study about the relation between stellar mass and gas-phase metallicity in the VIMOS VLT Deep Survey (VVDS). In this work we extend the determination of metallicities up to redshift = 1.24 for a sample of 42 star-forming galaxies with a mean redshift value of 0.99. Methods. For a selected sample of emission-line galaxies, we use both diagnostic diagrams and empirical calibrations based on [OII] emission lines along with the empirical relation between the intensities of the [OIII] and [NeIII] emission lines and the theoretical ratios between Balmer recombi…
We investigate the redshift and luminosity evolution of the galaxy colour-density relation using the data from the First Epoch VIMOS-VLT Deep Survey (VVDS). The size (6582 galaxies), depth (I_AB<=24) and redshift sampling rate of the survey enable us to reconstruct the 3D galaxy environment on relatively local scales (R=5 Mpc) up to z~1.5. Particular attention has been devoted to calibrate a density reconstruction scheme, which factors out survey selection effects and reproduces in an unbiased way the underlying `real' galaxy environment. While at lower redshift we confirm the existence of a s…
We present photometric redshifts for an uniquely large and deep sample of 522286 objects with i'_{AB}<25 in the Canada-France Legacy Survey ``Deep Survey'' fields, which cover a total effective area of 3.2 deg^2. We use 3241 spectroscopic redshifts with 0<z<5 from the VIMOS VLT Deep Survey as a calibration to derive these photometric redshifts. We devise a robust calibration method which removes systematic trends in the photometric redshifts and significantly reduces the fraction of catastrophic errors. We use our unique spectroscopic sample to present a detailed assessment of the robustness o…
We selected a mass-limited sample of 4048 objects from the VIMOS VLT Deep Survey in the redshift interval 0.5<z<1.3. We used the amplitude of the 4000 Balmer break (Dn4000) to separate the galaxy population and the EW[OII]3727 line as proxy for the star formation activity. We discuss to what extent stellar mass drives galaxy evolution, showing for the first time the interplay between stellar ages and stellar masses over the past 8Gyr. Low-mass galaxies have small Dn4000 and at increasing stellar mass, the galaxy distribution moves to higher Dn4000 values as observed in the local Universe. As c…
In this paper we discuss the mix of star-forming and passive galaxies up to z~2, based on the first epoch VIMOS-VLT Deep Survey (VVDS) data.In agreement with previous works we find that the galaxy rest-frame color distribution follows a bimodal distribution at z<=1, and we establish that this bimodality holds up to z~2. The details of the rest-frame color distribution depend however on redshift and on galaxy luminosity: faint galaxies are bluer than the luminous ones over the whole redshift range of our data, and galaxies become bluer as redshift increases. This blueing trend does not depend, …
We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey first observations of 21000 spectra in 1.75 square degree. This sample, which is purely magnitude limited, free of morphological or color selection biases, contains 130 broad line AGN (BLAGN) spectra with redshift up to 5. Our data are divided into a wide (Iab < 22.5) and a deep (Iab < 24) subsample containing 56 and 74 objects respectively. Because of its depth and selection criteria, this sample is uniquely suited to study the population of faint type-1 AGN. Our measured surface density (~ 472 …
We present the first results of a survey to obtain Integral Field Spectroscopy of merging galaxies along the Toomre Sequence. In the present work, we concentrate on the star cluster complexes in the Antennae galaxies (NGC 4038/39) in the overlap region as well as the nuclear region of NGC 4038. Using optical spectroscopy we derive the extinction age, metallicity, velocity, velocity dispersion of the gas and star formation rate for each of the eight complexes detected. We supplement this study with archival HST-WFPC2 U, B, V, H$α$, and I band imaging. Correcting the observed colours of the star…
We measure the evolution of clustering for galaxies with different spectral types from 6495 galaxies with 17.5<=I_AB<=24 and measured spectroscopic redshift in the first epoch VIMOS-VLT Deep Survey. We classify our sample into 4 classes, based on the fit of well-defined galaxy spectral energy distributions on observed multi-color data. We measure the projected function wp(rp) and estimate the best-fit parameters for a power-law real-space correlation function. We find the clustering of early-spectral-type galaxies to be markedly stronger than that of late-type galaxies at all redshifts up to z…
We present results from a pilot study of radial stellar population trends in early-type galaxies using the VLT VIMOS integral field unit (IFU). We observe twelve galaxies in the cluster Abell 3389 (z~0.027). For each galaxy, we measure 22 line-strength indices in multiple radial bins out to at least the effective radius. We derive stellar population parameters using a grid inversion technique, and calculate the radial gradients in age, metallcity and alpha-abundance. Generally, the galaxies in our sample have flat radial trends in age and [alpha/Fe], but negative gradients in [Z/H] (-0.20 +/- …
We present the on-going observational program of a VIMOS Integral Field Unit survey of the central regions of massive, gravitational lensing galaxy clusters at redshift z~0.2. We have observed six clusters using the low-resolution blue grism (R about 200), and the spectroscopic survey is complemented by a wealth of photometric data, including Hubble Space Telescope optical data and near infrared VLT data. The principal scientific aims of this project are: the study of the high-z lensed galaxies, the transformation and evolution of galaxies in cluster cores and the use of multiple images to con…
This paper presents the evolution of the clustering of the main population of galaxies from z=2.1 to z=0.2, from the first epoch VIMOS VLT Deep Survey (VVDS), a magnitude limited sample with 17.5<=I_{AB}<=24. We have computed the correlation functions ξ(r_p,π) and w_p(r_p), and the correlation length r_0(z), for the VVDS-02h and VVDS-CDFS fields, for a total of 7155 galaxies in a 0.61deg^2 area. We find that the correlation length in this sample stays roughly constant from z=0.5 to z=1.1, with r_0(z)=2.5-2.8 h^{-1} Mpc (comoving), for galaxies comparable in luminosity to the local 2dFGRS and S…
We are using VIMOS to conduct a wide-field spectroscopic survey covering fields of 0.5 x 0.5 sqdeg around the X-ray luminous clusters of galaxies Abell 1689 (z = 0.185) and Abell 1835 (z = 0.25). Here we describe the observations and first results on the redshift distribution of subsamples of cluster galaxies to R~22 for which we at present have obtained secure redshifts. These subsamples constitute ~40% of the total spectroscopic sample and contain 525 and 630 cluster members in Abell 1689 and Abell 1835, respectively, placing them amongst the largest redshift samples available for any cluste…
From the VIMOS VLT Deep Survey we use a sample of 6447 galaxies with I_{AB} < 24 to identify 251 pairs of galaxies, each member with a secure spectroscopic redshift, which are close in both projected separation and in velocity. We find that at z ~ 0.9, 10.9 +/- 3.2 % of galaxies with M_B(z) < -18-Qz are in pairs with separations dr < 20 kpc/h, dv < 500 km/s, and with dM_B < 1.5, significantly larger than 3.76 +/- 1.71 % at z ~ 0.5; we find that the pair fraction evolves as (1+z)^m with m = 2.49 +/- 0.56. For brighter galaxies with M_B(z=0) < -18.77, the pair fraction is higher and its evolutio…
Research on the core of medium and high z clusters of galaxies can derive great benefits from integral field spectroscopy, and a key role in this respect will be played by the Integral Field Unit (IFU) being developed by the VIRMOS Consortium as part of the VIMOS spectrograph. After a brief technical outline of the instrument, some of the problems to be addressed by data reduction techniques are described, and the scientific issues to which VIMOS IFU is likely to give its major contribution are pointed out.
We present a detailed analysis of the Galaxy Stellar Mass Function of galaxies up to z=2.5 as obtained from the VVDS. We estimate the stellar mass from broad-band photometry using 2 different assumptions on the galaxy star formation history and show that the addition of secondary bursts to a continuous star formation history produces systematically higher (up to 40%) stellar masses. At low redshift (z=0.2) we find a substantial population of low-mass galaxies (<10^9 Msun) composed by faint blue galaxies (M_I-M_K=0.3). In general the stellar mass function evolves slowly up to z=0.9 and more sig…
Aims: We use the VVDS-Deep first-epoch data to measure the dependence of galaxy clustering on galaxy stellar mass, at z~0.85. Methods: We measure the projected correlation function wp(rp) for sub-samples with 0.5<z<1.2 covering different mass ranges between 10^9 and 10^11 Msun. We quantify in detail the observational selection biases using 40 mock catalogues built from the Millennium run and semi-analytic models. Results: Our simulations indicate that serious incompleteness in mass is present only for log(M/Msun)<9.5. In the mass range log(M/Msun)=[9.0-9.5], the photometric selection function …
With new generation spectrographs integral field spectroscopy is becoming a widely used observational technique. The Integral Field Unit of the VIsible Multi-Object Spectrograph on the ESO-VLT allows to sample a field as large as 54" x 54" covered by 6400 fibers coupled with micro-lenses. We are presenting here the methods of the data processing software developed to extract the astrophysical signal of faint sources from the VIMOS IFU observations. We focus on the treatment of the fiber-to-fiber relative transmission and the sky subtraction, and the dedicated tasks we have built to address the…
We study the LF of the high-z galaxy population with 3<z<4 using a purely I-band magnitude-selected spectroscopic sample obtained in the framework of the VVDS. We determine the LF from the VVDS, taking care to add as few assumptions and as simple corrections as possible, and compare our results with those obtained from photometric studies, based on Lyman-break selections or photo-z measurements. We find that in the range 3<z<4, the VVDS LF is parameterized by phi*=1.24+-0.50 10-3 mag-1 Mpc-3 and M*=-21.49+-0.19, assuming a slope alpha=-1.4 consistent with most previous studies. While phi* is c…
(abridged) The ESIS survey is the optical follow up of the SWIRE/Spitzer in the ELAIS-S1 region of the sky. In the era of observational cosmology, the main efforts are focused on the study of galaxy evolution and its environmental dependence. Wide area, multiwavelength, extragalactic surveys are needed in order to probe sufficiently large volumes, minimize cosmic variance and find significant numbers of rare objects. We present VIMOS I and z band imaging belonging to the ESIS survey. A total of ~4 deg2 were targeted in I and ~1 deg2 in z. More than 300000 galaxies have been detected in the I b…
From the first epoch observations of the VVDS up to z=1.5 we have derived luminosity functions (LF) of different spectral type galaxies. The VVDS data, covering ~70% of the life of the Universe, allow for the first time to study from the same sample and with good statistical accuracy the evolution of the LFs by galaxy type in several rest frame bands from a purely magnitude selected sample. The magnitude limit of the VVDS allows the determination of the faint end slope of the LF with unprecedented accuracy. Galaxies have been classified in four spectral classes, using their colours and redshif…
We present the evolution of the comoving SFR density in the redshift range 0 < z < 5 using the first epoch data release of the VVDS, that is 11564 spectra selected at I_AB=24 over 2200 arcmin^2 in two fields of view, the VVDS-0226-04 and the VVDS-CDFS-0332-27, and the cosmological parameters (Omega_M, Omega_L, h)=(0.3, 0.7, 0.7). We study the multi-wavelength non dust-corrected luminosity densities at 0 < z < 2 from the rest-frame FUV to the optical passbands, and the rest-frame 1500A luminosity functions and densities at 2.7 < z < 5. They evolve from z=1.2 to 0.05 according to (1+z)^{x} with …
We present an integral field spectroscopy survey of rich clusters of galaxies aimed at studying their lensing properties. Thanks to knowledge of the spectroscopic caracteristics of more than three families of multiple images in a single lens, one is able in principle to derive constraints on the geometric cosmological parameters. We show that this ambitious program is feasible and present some new results, in particular the redshift measurement of the giant arc in A2667 and the resdshift confirmation of the counter-image of the radial arc in MS2137--23. Prospects for the future of such program…
Recent results on the evolution of Local Group dwarf galaxies obtained from VLT imaging and spectroscopy are briefly reviewed, and prospects for dwarf galaxy research at the VLT are discussed in the light of the current and forthcoming instrumentation. Some aspects of future instrument developments, such as deep wide-field imaging at both optical and near-infrared wavelengths that may be of advantage for research on the evolution of dwarf galaxies, are briefly discussed.
Here we describe some of our latest results from measuring detailed abundances in Local Group dwarf galaxies with VLT. Combining spectroscopic abundances with Colour-Magnitude diagrams allows the effective measurement of detailed chemical evolution with time in these galaxies. Although there are not yet significant numbers of individual stars observed in local group dwarf galaxies the uniformity of the abundance patterns of the majority of stars in galaxies with very different star formation histories must hint at a general properties of all star formation in these small systems.
The aim of the work presented in this paper is to test and optimise supernova detection methods based on the optimal image subtraction technique. The main focus is on applying the detection methods to wide field supernova imaging surveys and in particular to the Stockholm VIMOS Supernova Survey (SVISS). We have constructed a supernova detection pipeline for imaging surveys. The core of the pipeline is image subtraction using the ISIS 2.2 package. Using real data from the SVISS we simulate supernovae in the images, both inside and outside galaxies. The detection pipeline is then run on the simu…
The study of high-$z$ radio galaxies (HZRGs) has matured considerably during the last decade. Large numbers of $z>2$ radio galaxies have been found and have been studied in considerable detail. In this review we will address the importance of the VLT for studies of samples of distant radio galaxies. We shall first briefly discuss the importance of radio galaxies for cosmological studies. Then we shall summarize the various emitting components associated with these objects and comment on the possibilities offered by the VLT for detailed observations of these components and the radio/optical ali…
We present the motivation, aims and preliminary result from the Swift/VLT legacy survey on gamma-ray burst host galaxies. This survey will produce a homogeneous and well-understood host sample covering more than 95% of the lookback time to the Big Bang, and allow us to characterize their fundamental properties.
A new population of faint galaxies characterized by an extremely high rate of evolution with redshift up to z~1.5 has recently been discovered by ISO. These sources are likely to contribute significantly to the cosmic far-IR extragalactic background. We have carried out near-infrared VLT-ISAAC spectroscopy of a sample of ISOCAM galaxies from the Hubble Deep Field South. The rest-frame R-band spectral properties of the ISO population resembles that of powerful dust-enshrouded active starburst galaxies.
We present a study of the internal kinematics and stellar populations of early-type galaxies in the Fornax cluster based on integral-field spectroscopic observations with Gemini South GMOS and VLT-VIMOS. Seven galaxies in a luminosity range of -21.3 < M_B < -17.7 have been observed with these integral field units (IFU). As first results, velocity and line strength maps are presented for NGC 1427 and NGC 1419.
The aim of the VIRMOS VLT Deep Survey (VVDS) is to study of the evolution of galaxies, large scale structures and AGNs from a sample of more than 150,000 galaxies with measured redshifts in the range 0<z<5+. The VVDS will rely on the VIMOS and NIRMOS wide field multi-object spectrographs, which the VIRMOS consortium is delivering to ESO. Together, they offer unprecedented multiplex capability in the wavelength range 0.37-1.8microns, allowing for large surveys to be carried out. The VVDS has several main aspects: (1) a deep multi-color imaging survey over 18deg^2 of more than one million galaxi…
Interest in the quasar HE0450-2958 arose following the publication of the non-detection of its expected massive host, leading to various interpretations. This article investigates the gaseous and stellar contents of the system through additional VLT/FORS slit spectra and integral field spectroscopy from VLT/VIMOS. We apply our MCS deconvolution algorithm on slit spectra for the separation of the QSO and diffuse components, and develop a new method to remove the point sources in Integral Field Spectra, allowing extraction of velocity maps, narrow-line images, spatially resolved spectra or ioniz…
The combination of two-dimensional kinematics and gravitational lens modelling permits detailed reconstruction of the phase-space structure of early-type galaxies and sets constraints on the dark-matter distribution in their inner regions. We describe a project which combines integral-field spectroscopy from an ESO Large Programme using VIMOS on the VLT with deep HST ACS and NICMOS images to study a sample of 17 early-type lens galaxies at redshifts between 0.1 and 0.3, drawn from the Sloan Lens ACS survey (SLACS).
