- ID:
- ivo://CDS.VizieR/J/ApJ/475/445
- Title:
- VIK photometry of faint field galaxies
- Short Name:
- J/ApJ/475/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We combine deep K-band (W. M. Keck Telescope) with V- and I-band (New Technology Telescope) observations of two "blank" high Galactic latitude fields, surveying a total of ~2arcmin^2^. The K-band number-magnitude counts continue to rise above K~22mag, reaching surface densities of few x10^5^deg^-2^. The slope for the galaxy counts is approximately [dlog(N)/dmag].deg^-2^=0.23+/-0.02 over the range 18-23mag. While this slope is consistent with other recent deep K-band surveys, there is a definite scatter in the normalisations by about a factor of 2. In particular, our normalisation is ~2x greater than the galaxy counts reported by Djorgovski et al. in 1995 (1995ApJ...438L..13D). Optical near-infrared color-magnitude and color-color diagrams for all objects detected in the V+I+K image are plotted and discussed in the context of grids of Bruzual-Charlot isochrone synthesis galaxy evolutionary models. The colors of most of the observed galaxies are consistent with a population drawn from a broad redshift distribution. A few galaxies at K~19-20 are red in both colors (V-I>3; I-K>2, consistent with being early-type galaxies having undergone a burst of star formation at z>5 and viewed at z~1. At K>20, we find several (approximately eight) "red outlier" galaxies with I-K>4 and V-I<2.5, whose colors are difficult to mimic by a single evolving or nonevolving stellar population at any redshift unless they either have quite low metallicity or are highly reddened. We compare the data against the evolutionary tracks of second-burst ellipticals and against a grid of models that does not constrain galaxy ages to a particular formation redshift. The red outliers' surface density is several per square arcminute, which is so high that they are probably common objects of low luminosity L<L*. Whether these are low-metallicity, dusty dwarf galaxies, or old galaxies at high redshift, they are curious and merit spectroscopic follow-up.
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- ID:
- ivo://CDS.VizieR/J/AJ/136/1770
- Title:
- VI light curves of NGC 247 Cepheids
- Short Name:
- J/AJ/136/1770
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the discovery of a Cepheid population in the Sculptor Group spiral galaxy NGC 247 for the first time. On the basis of wide-field images collected in photometric surveys in V and I bands that were conducted with three different telescopes and cameras, 23 Cepheid variables were discovered with periods ranging from 17 to 131 days.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A185
- Title:
- VI magnitudes of NGC 4535 stars
- Short Name:
- J/A+A/618/A185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyzed the massive star population of the Virgo Cluster galaxy NGC 4535 using archival Hubble Space Telescope Wide Field Planetary Camera 2 images in filters F555W and F814W, equivalent to Johnson V and Kron-Cousins I. We performed high precision point spread function fitting photometry of 24353 sources including 3762 candidate blue supergiants, 841 candidate yellow supergiants and 370 candidate red supergiants. We estimated the ratio of blue to red supergiants as a decreasing function of galactocentric radius. Using Modules for Experiments in Stellar Astrophysics isochrones at solar metallicity, we defined the luminosity function and estimated the star formation history of the galaxy over the last 60Myrs. We conducted a variability search in the V and I filters using three variability indexes: the median absolute deviation, the interquartile range and the inverse von-Neumann ratio. This analysis yielded 120 new variable candidates with absolute magnitudes ranging from M_V_=-4 to -11mag. We used the MESA evolutionary tracks at solar metallicity, to classify the variables based on their absolute magnitude and their position on the color-magnitude diagram. Among the new candidate variable sources are eight candidate variable red supergiants, three candidate variable yellow supergiants and one candidate luminous blue variable, which we suggest for follow-up observations.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A23
- Title:
- VIMOS Public Extragalactic Survey (VIPERS) DR1
- Short Name:
- J/A+A/562/A23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first Public Data Release (PDR-1) of the VIMOS Public Extragalactic Survey (VIPERS). It comprises 57204 spectroscopic measurements together with all additional information necessary for optimal scientific exploitation of the data, in particular the associated photometric measurements and quantification of the photometric and survey completeness. VIPERS is an ESO Large Programme designed to build a spectroscopic sample of =~100000 galaxies with i_AB_<22.5 and 0.5<z<1.2 with high sampling rate (=~45%). The survey spectroscopic targets are selected from the CFHTLS-Wide five-band catalogues in the W1 and W4 fields. The final survey will cover a total area of nearly 24 deg^2^, for a total comoving volume between z=0.5 and 1.2 of =~4x10^7^(Mpc/h)^3^ and a median galaxy redshift of z=~0.8. The release presented in this paper includes data from virtually the entire W4 field and nearly half of the W1 area, thus representing 64% of the final dataset. We provide a detailed description of sample selection, observations and data reduction procedures; we summarise the global properties of the spectroscopic catalogue and explain the associated data products and their use, and provide all the details for accessing the data through the survey database (http://vipers.inaf.it) where all information can be queried interactively.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A110
- Title:
- VIMOS Ultra Deep Survey (VUDS) DR1
- Short Name:
- J/A+A/600/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper describes the first data release (DR1) of the VIMOS Ultra Deep Survey (VUDS). The VUDS-DR1 is the release of all low-resolution spectroscopic data obtained in 276.9 arcmin^2^ of the CANDELS-COSMOS and CANDELS-ECDFS survey areas, including accurate spectroscopic redshifts z_spec_ and individual spectra obtained with VIMOS on the ESO-VLT. A total of 698 objects have a measured redshift, with 677 galaxies, two type-I AGN, and a small number of 19 contaminating stars. The targets of the spectroscopic survey are selected primarily on the basis of their photometric redshifts to ensure a broad population coverage. About 500 galaxies have z_spec_>2, 48of which have z_spec_>4; the highest reliable redshifts reach beyond z_spec_=6. This data set approximately doubles the number of galaxies with spectroscopic redshifts at z>3 in these fields. We discuss the general properties of the VUDS-DR1 sample in terms of the spectroscopic redshift distribution, the distribution of Lyman-{alpha} equivalent widths, and physical properties including stellar masses M* and star formation rates derived from spectral energy distribution fitting with the knowledge of z_spec_. We highlight the properties of the most massive star-forming galaxies, noting the wide range in spectral properties, with Lyman-{alpha} in emission or in absorption, and in imaging properties with compact, multi-component, or pair morphologies. We present the catalogue database and data products. All VUDS-DR1 data are publicly available and can be retrieved from a dedicated query-based database. Future VUDS data releases will follow this VUDS-DR1 to give access to the spectra and associated measurement of ~8000 objects in the full ~1 square degree of the VUDS survey.
- ID:
- ivo://CDS.VizieR/J/A+A/559/A14
- Title:
- VIMOS VLT Deep Survey final data release
- Short Name:
- J/A+A/559/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep representative surveys of galaxies at different epochs are needed to make progress in understanding galaxy evolution. We describe the completed VIMOS VLT Deep Survey and the final data release of 35016 galaxies and type-I AGN with measured spectroscopic redshifts covering all epochs up to redshift z~6.7, in areas from 0.142 to 8.7 square degrees, and volumes from 0.5x10^6^ to 2x10^7^h^-3^*Mpc^3^. We selected samples of galaxies based solely on their i-band magnitude reaching i_AB_=24.75. Spectra were obtained with VIMOS on the ESO-VLT integrating 0.75h, 4.5h, and 18h for the Wide, Deep, and Ultra-Deep nested surveys, respectively. We demonstrate that any "redshift desert" can be crossed successfully using spectra covering 3650<={lambda}<=9350{AA}. A total of 1263 galaxies were again observed independently within the VVDS and from the VIPERS and MASSIV surveys. They were used to establish the redshift measurements reliability, to assess completeness in the VVDS sample, and to provide a weighting scheme taking the survey selection function into account. We describe the main properties of the VVDS samples, and the VVDS is compared to other spectroscopic surveys in the literature. In total we have obtained spectroscopic redshifts for 34594 galaxies, 422 type-I AGN, and 12430 Galactic stars. The survey enabled identifying galaxies up to very high redshifts with 4669 redshifts in 1<=z_spec_<=2, 561 in 2<=z_spec_<=3, and 468 with z_spec_>3, and specific populations like Lyman-{alpha} emitters were identified out to z=6.62. We show that the VVDS occupies a unique place in the parameter space defined by area, depth, redshift coverage, and number of spectra. The VIMOS VLT Deep Survey provides a comprehensive survey of the distant universe, covering all epochs since z~6, or more than 12Gyr of cosmic time, with a uniform selection, which is the largest such sample to date. A wealth of science results derived from the VVDS have shed new light on the evolution of galaxies and AGN and on their distribution in space over this large cosmic time. The VVDS further demonstrates that large deep spectroscopic redshift surveys over all these epochs in the distant Universe are a key tool to observational cosmology. To enhance the legacy value of the survey, a final public release of the complete VVDS spectroscopic redshift sample is available at http://cesam.lam.fr/vvds .
- ID:
- ivo://CDS.VizieR/J/A+A/563/A92
- Title:
- VIPERS: galaxy colours and luminosity function
- Short Name:
- J/A+A/563/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore the evolution of the colour-magnitude relation (CMR) and luminosity function (LF) at 0.4<z<1.3 from the VIMOS Public Extragalactic Redshift Survey (VIPERS) using ~45000 galaxies with precise spectroscopic redshifts down to i'_AB_<22.5 over ~10.32deg^2^ in two fields. From z=0.5 to z=1.3 the LF and CMR are well defined for different galaxy populations and M^*^_B_ evolves by ~1.04(1.09)+/-0.06(0.10) mag for the total (red) galaxy sample. We compare different criteria for selecting early-type galaxies: (1) a fixed cut in rest-frame (U-V) colours, (2) an evolving cut in (U-V) colours, (3) a rest-frame (NUV-r')-(r'-K) colour selection, and (4) a spectral-energy-distribution classification. The completeness and contamination varies for the different methods and with redshift, but regardless of the method we measure a consistent evolution of the red-sequence (RS). Between 0.4<z<1.3 we find a moderate evolution of the RS intercept of {Delta}(U-V)=0.28+/-0.14 mag, favouring exponentially declining star formation (SF) histories with SF truncation at 1.7<=z<=2.3. Together with the rise in the number density of red galaxies by 0.64dex since z=1, this suggests a rapid build-up of massive galaxies (M_*_>10^11^M_{sun}_) and expeditious RS formation over a short period of ~1.5Gyr starting before z=1. This is supported by the detection of ongoing SF in early-type galaxies at 0.9<z<1.0, in contrast with the quiescent red stellar populations of early-type galaxies at 0.5<z<0.6. There is an increase in the observed CMR scatter with redshift, which is two times larger than observed in galaxy clusters and at variance with theoretical model predictions. We discuss possible physical mechanisms that support the observed evolution of the red galaxy population. Our findings point out that massive galaxies have experienced a sharp SF quenching at z~1 with only limited additional merging. In contrast, less-massive galaxies experience a mix of SF truncation and minor mergers which build-up the low- and intermediate-mass end of the CMR.
- ID:
- ivo://CDS.VizieR/J/A+A/590/A102
- Title:
- VIPERS Multi-Lambda Survey
- Short Name:
- J/A+A/590/A102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations collected in the CFHTLS-VIPERS region in the ultraviolet with the GALEX satellite (far- and near-ultraviolet channels) and in the near-infrared with the CFHT/WIRCam camera (Ks band) over an area of 22 and 27deg^2^, respectively. The depth of the photometry was optimised to measure the physical properties (e.g., star formation rate, stellar masses) of all the galaxies in the VIPERS spectroscopic survey. The large volume explored by VIPERS will enable a unique investigation of the relationship between the galaxy properties and their environment (density field and cosmic web) at high redshift (0.5<=z<=1.2). In this paper, we present the observations, the data reductions, and the build-up of the multi-colour catalogues. The CFHTLS-T0007 (gri-{chi}^2^) images are used as reference to detect and measure the Ks -band photometry, while the T0007 u*-selected sources are used as priors to perform the GALEX photometry based on a dedicated software (EMphot). Our final sample reaches NUV_AB_~25 (at 5{sigma}) and K_AB_~22 (at 3{sigma}). The large spectroscopic sample (~51,000 spectroscopic redshifts) allows us to highlight the robustness of our star/galaxy separation and the reliability of our photometric redshifts with a typical accuracy of {sigma]_z_<=0:04 and a fraction of catastrophic failures {eta}<=2% down to i~23. We present various tests on the Ks -band completeness and photometric redshift accuracy by comparing our results with existing overlapping deep photometric catalogues. Finally, we discuss the BzK sample of passive and active galaxies at high redshift and the evolution of galaxy morphology in the (NUV-r) vs (r-Ks) diagram at low redshift (z<=0.25) based on the high image quality of the CFHTLS. The images, catalogues, and photometric redshifts for 1.5 million sources (down to NUV<=25 {union} Ks<=22) are released and available at this URL: http://cesam.lam.fr/vipers-mls/.
- ID:
- ivo://lam.cesam.aspic/vipers_dr2/q/ssa
- Title:
- VIPERS PDR-2 - Simple Spectrum Access
- Short Name:
- VIPERS2 SSAP
- Date:
- 24 Aug 2021 14:22:40
- Publisher:
- The CeSAM VO team
- Description:
- Spectra from the second data release (PDR-2) of VIPERS.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A106
- Title:
- VIPERS. Searching for cosmic voids
- Short Name:
- J/A+A/570/A106
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Characterisation of cosmic voids gives unique information about the large-scale distribution of galaxies, their evolution, and the cosmological model. We identify and characterise cosmic voids in the VIMOS Public Extragalactic Redshift Survey (VIPERS) at redshift 0.55 <z< 0.9. A new void search method is developed based upon the identification of empty spheres that fit between galaxies. The method can be used to characterise the cosmic voids despite the presence of complex survey boundaries and internal gaps. We investigate the impact of systematic observational effects and validate the method against mock catalogues. We measure the void size distribution and the void-galaxy correlation function.
