- ID:
- ivo://CDS.VizieR/J/BaltA/14/179
- Title:
- Vilnius photometry of NGC 1647 area
- Short Name:
- J/BaltA/14/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The area of the open cluster NGC 1647 in Taurus is investigated by CCD photometry in the Vilnius seven-color system. Magnitudes and color indices are determined for 433 stars down to V=15.0mag in the 45arcmin diameter area. For 252 of them photometric spectral and luminosity classes, interstellar reddenings, extinctions and distances are obtained. According to the CDS WEBDA database, 89 of them have a high cluster membership probability. Their mean distance from the Sun is 555+/-74pc, excluding four stars which seem to be field stars. The main sequence starts at spectral class B7 V which corresponds to a cluster age of about 150 million years. Cluster members show a differential interstellar extinction ranging from 0.8 to 1.8mag. The mean extinction of the cluster stars is 1.12+/-0.25mag. Interstellar extinction in the area is dominated by the Taurus dark cloud complex at 160pc. Color excesses of individual stars correlate well with the 100um dust thermal emission intensity. The cluster shape is investigated by counting stars down to K=15.6mag and is found to be elongated in the direction roughly perpendicular to the Milky Way, with the flattening 0.4.
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Search Results
- ID:
- ivo://CDS.VizieR/J/BaltA/8/443
- Title:
- Vilnius photometry of stars near NGP
- Short Name:
- J/BaltA/8/443
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photoelectric seven-color photometry in the Vilnius medium-band system has been obtained for 374 stars in four MEGA proper-motion fields, KA 112, KA 113, KA 118 and KA 119, each of about 1.4 square degree size, near the North Galactic Pole. The catalog of observations is complete down to nearly V=13.0mag, except for the one field, KA 118, for which the completeness is achieved down to only V=12.5mag. For a description of the Vilnius photometric system, see e.g. <GCPD/21>
- ID:
- ivo://CDS.VizieR/J/BaltA/22/243
- Title:
- Vilnius photometry of TGU H994
- Short Name:
- J/BaltA/22/243
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of CCD photometry in the seven-color Vilnius system are given for 727 stars down to V~17 mag in a 1.5 square degree field in the region of dark cloud TGU H994 P1 (or LDN 1399, LDN 1400 and LDN 1402) in Camelopardalis. Using the intrinsic color indices and photometric reddening-free Q-parameters, two-dimensional spectral types for 73% of stars are determined.
- ID:
- ivo://CDS.VizieR/J/A+A/585/A31
- Title:
- Vilnius photometry of TGU H994 P1
- Short Name:
- J/A+A/585/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of CCD photometry in the seven-color Vilnius system are given for 855 stars down to V~20mag in three 12x12 arcmin areas of the dark cloud TGU H994P1. Observational data were obtained in 2014-2015 with the 1.8m VATT telescope of the Vatican Observatory on Mt Graham, Arizona. Two-dimensional classification in the MK system is given for about 65% of stars.
- ID:
- ivo://CDS.VizieR/J/A+A/458/767
- Title:
- Vilnius photometry on M92
- Short Name:
- J/A+A/458/767
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations of the northern globular cluster M 92 were obtained in the PXYVS colors of the Vilnius photometric system. The results for 230 stars in an area centered on the cluster and for 178 stars in an area west of the cluster down to V=17.0mag are presented. After a brief outline of the data pathway from observations to reduction via IRAF and a discussion of the photometric errors, the [Fe/H] ratio of the globular cluster M 92 is determined by multicolor PXYVS Vilnius photometry.
- 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/457/79
- Title:
- VIMOS VLT Deep Survey: faint type-1 AGN sample
- Short Name:
- J/A+A/457/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the type-1 active galactic nuclei (AGN) sample extracted from the VIMOS VLT Deep Survey's first observations of 21000 spectra in 1.75{deg}^2^. This sample, which is purely magnitude-limited and 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 (I_AB_<=22.5) and a deep (I_AB_<=24) subsample containing 56 and 74 objects, respectively. Because of its depth and selection criteria, this sample is uniquely suited for studying the population of faint type-1 AGN. Our measured surface density (~472+/-48 BLAGN per square degree with I_AB_<=24) is significantly higher than that of any other optically selected sample of BLAGN with spectroscopic confirmation. By applying a morphological and color analysis to our AGN sample, we find that (1) ~23% of the AGN brighter than I_AB_=22.5 are classified as extended, and this percentage increases to ~42 for those with z<1.6; (2) a non-negligible fraction of our BLAGN are lying close to the color-space area occupied by stars in the u*-g' versus g'-r' color-color diagram. This leads us to the conclusion that the classical optical-ultraviolet preselection technique, if employed at such deep magnitudes (I_AB_=22.5) in conjuction with a preselection of point-like sources, can miss up to ~35% of the AGN population. Finally, we present a composite spectrum of our sample of objects. While the continuum shape is very similar to that of the SDSS composite at short wavelengths, it is much redder than that of the SDSS composite at {lambda}>=3000{AA}. We interpret this as due to significant contamination from emission of the host galaxies, as expected from the faint absolute magnitudes sampled by our 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.
