- ID:
- ivo://CDS.VizieR/J/A+A/550/A93
- Title:
- VI light curves of V383 Sco
- Short Name:
- J/A+A/550/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The system V383 Sco was discovered to be an eclipsing binary star at the beginning of the twentieth century. This system has one of the longest orbital periods known (13.5yr) and was initially classified as a zeta Aur-type eclipsing variable. It was then forgotten about for decades, with no progress made in understanding it. This study provides a detailed look at the system V383 Sco, using new data obtained before, during and after the last eclipse, which occurred in 2007/8. There was a suspicion that this system could be similar to eclipsing systems with extensive dusty disks like EE Cep and epsilon Aur. This and other, alternative hypotheses are considered here. The All Sky Automated Survey (ASAS-3) V and I light curves have been used to examine apparent magnitude and colour changes. Low- and high- resolution spectra have been obtained and used for spectral classification, to analyse spectral line profiles, as well as to determine the reddening, radial velocities and the distance to the system. The spectral energy distribution (SED) was analysed using all available photometric and spectroscopic data. Using our own original numerical code, we performed a very simplified model of the eclipse, taking into account the pulsations of one of the components. The low-resolution spectrum shows apparent traces of molecular bands, characteristic of an M-type supergiant. The presence of this star in the system is confirmed by the SED, by a strong dependence of the eclipse depth on the photometric bands, and by the nature of pulsational changes. The presence of a very low excitation nebula around the system has been inferred from [OI] 6300{AA} emission in the high-resolution spectrum. Analysis of the radial velocities, reddening, and period-luminosity relation for Mira-type stars imply a distance to the V383 Sco system of 8.4+/-0.6kpc. The distance to the nearby V381 Sco is 6.4+/-0.8kpc. The very different and oppositely directed radial velocities of these two systems (89.8km/s vs -178.8km/s) seem to be in agreement with a bulge/bar kinematic model of the Galactic centre and inconsistent with purely circular motion. Conclusions. We have found strong evidence for the presence of a pulsating M-type supergiant in the V383 Sco system. This supergiant periodically obscures the much more luminous F0 I-type star, causing the deep (possibly total) eclipses which vary in duration and shape.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/544/A49
- Title:
- Vilnius photometry in North Ecliptic Pole
- Short Name:
- J/A+A/544/A49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 2 contains the results of photometry of 948 stars down to V=16.2mag in the Vilnius seven-color system at the North Ecliptic Pole. Photometric data are used to classify about 500 stars in spectral and luminosity classes. For the remaining stars one-dimensional spectral classes are given. The results of photometry and classification can be used to supplement the catalog of Gaia standard stars near the Ecliptic poles. To facilitate this, Table 3 presents the magnitudes of the SDSS and Gaia systems transformed from the Vilnius seven-color photometry.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/186/191
- Title:
- VI photometry and spectroscopy in h+{chi} Per
- Short Name:
- J/ApJS/186/191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From photometric observations of ~47000 stars and spectroscopy of ~11000 stars, we describe the first extensive study of the stellar population of the famous Double Cluster, h and {chi} Persei, down to subsolar masses. By analyzing optical spectra and optical/infrared photometry, we constrain the distance moduli (dM), reddening (E(B-V)), and ages for h Persei, {chi} Persei, and the low-density halo population surrounding both cluster cores. With the exception of mass and spatial distribution, the clusters are nearly identical in every measurable way. From these data, we establish the first spectroscopic and photometric membership lists of cluster stars down to early/mid M dwarfs. At minimum, there are ~5000 members within 10' of the cluster centers, while the entire h and {chi} Persei region has at least ~13000 and as many as 20000 members. The Double Cluster contains ~8400M_{sun}_ of stars within 10' of the cluster centers. We estimate a total mass of at least 20000M_{sun}_. We conclude our study by outlining outstanding questions regarding the past and present properties of h and {chi} Persei. From comparing recent work, we compile a list of intrinsic colors and derive a new effective temperature scale for O-M dwarfs, giants, and supergiants.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A96
- Title:
- VI photometry in 3 dwarf galaxies
- Short Name:
- J/A+A/615/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The abundance and spatial distribution of dwarf galaxies are excellent empirical benchmarks against which to test models of structure formation on small scales. The nearby Centaurus group, with its two subgroups centered on Cen A and M 83, stands out as an important alternative to the Local Group for scrutinizing cosmological model predictions in a group of galaxies context. We have obtained deep optical images of three recently discovered M 83 satellite galaxy candidates with the FORS2 instrument mounted on the Very Large Telescope. We aim to confirm their group membership and study their stellar population. Deep V I-band photometry was used to resolve the brightest stars in our targets. Artificial star tests are performed to estimate the completeness and uncertainties of the photometry. The color-magnitude diagrams reveal the red giant branch (RGB) stars, allowing us to use the Sobel edge detection method to measure the magnitude of the RGB tip and thus derive distances and group membership for our targets. The mean metallicity of the dwarf galaxies were further determined by fitting BASTI model isochrones to the mean RGB locus.
- ID:
- ivo://CDS.VizieR/J/A+A/396/473
- Title:
- VI Photometry in M81 Group
- Short Name:
- J/A+A/396/473
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive quantitative star formation histories of the four suspected tidal dwarf galaxies in the M 81 group, Holmberg IX, BK3N, Arp-loop (A0952+69), and Garland, using Hubble Space Telescope/Wide Field Planetary Camera 2 images in F606W and F814W obtained as part of a Snapshot survey of dwarf galaxies in the Local Universe.
- ID:
- ivo://CDS.VizieR/J/AJ/128/224
- Title:
- VI photometry in M33 outer regions
- Short Name:
- J/AJ/128/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep CCD photometry in the VI passbands using the WIYN 3.5m telescope of a field located approximately 20 southeast of the center of M33; this field includes the region studied by Mould & Kristian in 1986ApJ...305..591M. The color-magnitude diagram (CMD) extends to I~25 and shows a prominent red giant branch (RGB), along with significant numbers of asymptotic giant branch and young main-sequence stars.
