- ID:
- ivo://CDS.VizieR/J/A+A/566/A43
- Title:
- EPOCH Project. EROS-2 LMC periodic variables
- Short Name:
- J/A+A/566/A43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The EPOCH (EROS-2 periodic variable star classification using machine learning) project aims to detect periodic variable stars in the EROS-2 light curve database. In order to classify these variables, we first build a training set by compiling known variables in the Large Magellanic Could area from the OGLE and MACHO surveys. We crossmatch these variables with the EROS-2 sources and extract 22 variability features from 28,392 light curves of the corresponding EROS-2 sources. We then use Random Forests to classify the EROS-2 sources in the training set. We design the model to separate not only Delta Scuti stars, RR Lyraes, Cepheids, eclipsing binaries and long-period variables, the "superclasses", but also their subclasses, such as RRab, RRc, RRd and RRe for RR Lyraes, and similarly for the other variable types. We apply the trained model to the entire EROS-2 LMC database containing about 29 million sources and find 117,234 periodic variable candidates. Out of these 117,234 periodic variables, 55,285 have not been discovered by either OGLE or MACHO variability studies. This set comprises 1906 Delta Scuti stars, 6,607 RR Lyraes, 638 Cepheids, 178 Type II Cepheids, 34,562 eclipsing binaries and 11,394 long-period variables.
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492. EREBOS project. I.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A80
- Title:
- EREBOS project. I.
- Short Name:
- J/A+A/630/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Eclipsing post-common-envelope binaries are highly important for resolving the poorly understood, very short-lived common-envelope phase of stellar evolution. Most hot subdwarfs (sdO/Bs) are the bare helium-burning cores of red giants that have lost almost all of their hydrogen envelope. This mass loss is often triggered by common-envelope interactions with close stellar or even substellar companions. Cool companions to hot subdwarf stars such as late-type stars and brown dwarfs are detectable from characteristic light-curve variations - reflection effects and often eclipses. In the recently published catalog of eclipsing binaries in the Galactic Bulge and in the Asteroid Terrestrial-impact Last Alert System (ATLAS) survey, we discovered 125 new eclipsing systems showing a reflection effect seen by visual inspection of the light curves and using a machine-learning algorithm, in addition to the 36 systems previously discovered by the Optical Gravitational Lesing Experiment (OGLE) team. The Eclipsing Reflection Effect Binaries from Optical Surveys (EREBOS) project aims at analyzing all newly discovered eclipsing binaries of the HW Vir type (hot subdwarf + close, cool companion) based on a spectroscopic and photometric follow up to derive the mass distribution of the companions, constrain the fraction of substellar companions, and determine the minimum mass needed to strip off the red-giant envelope. To constrain the nature of the primary we derived the absolute magnitude and the reduced proper motion of all our targets with the help of the parallaxes and proper motions measured by the Gaia mission and compared those to the Gaia white-dwarf candidate catalog. It was possible to derive the nature of a subset of our targets, for which observed spectra are available, by measuring the atmospheric parameter of the primary, confirming that less than 10% of our systems are not sdO/Bs with cool companions but are white dwarfs or central stars of planetary nebula. This large sample of eclipsing hot subdwarfs with cool companions allowed us to derive a significant period distribution for hot subdwarfs with cool companions for the first time showing that the period distribution is much broader than previously thought and is ideally suited to finding the lowest-mass companions to hot subdwarf stars. The comparison with related binary populations shows that the period distribution of HW Vir systems is very similar to WD+dM systems and central stars of planetary nebula with cool companions. In the future, several new photometric surveys will be carried out, which will further increase the sample of this project, providing the potential to test many aspects of common-envelope theory and binary evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/451/881
- Title:
- ESIS BVR catalog, ELAIS-S1
- Short Name:
- J/A+A/451/881
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO-Spitzer extragalactic Imaging Survey (ESIS) is the optical follow up of the Spitzer Wide-Area InfraRed Extragalactic (SWIRE) survey in the ELAIS-S1 area. The multiwavelength study of galaxy emission is the key to understand the interplay of the various components of galaxies and to trace their role in cosmic evolution. ESIS provides optical identification and colors of Spitzer IR galaxies and builds the bases for photometric redshift estimates. This paper presents B, V, R Wide Field Imager observations of the first 1.5 square degree of the ESIS survey. Data reduction includes astrometric calibration, illumination and color corrections. Synthetic sources are simulated in scientific and super-sky-flat images, with the purpose of estimating completeness and photometric accuracy for the survey. Number counts and color distributions are compared to literature observational and theoretical data, including non-evolutionary, PLE, evolutionary and semi-analytic Lambda-CDM galaxy models, as well as Milky Way stellar predictions. Object coordinates are defined with an accuracy as good as ~0.15" rms with respect to GSC 2.2; flux uncertainties are ~2, 10, 20% at mag. 20, 23, 24 respectively (Vega); we reach 95% completeness at B, V~25 and R~24.5. ESIS galaxy number counts are in good agreement with previous works and are best reproduced by evolutionary and hierarchical Lambda-CDM scenarios.
- ID:
- ivo://CDS.VizieR/J/A+A/488/533
- Title:
- ESIS VIMOS I,z photometry of ELAIS-S1
- Short Name:
- J/A+A/488/533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO-Spitzer Imaging extragalactic Survey (ESIS) is the optical follow up of the Spitzer Wide-area Infra-Red Extragalactic survey (SWIRE) in the ELAIS-S1 region of the sky. We present VIMOS I and z band imaging belonging to the ESIS survey. A total of ~4 square degrees were targeted in I and ~1 in z. Accurate data processing includes removal of fringing, and mosaicking of the complex observing pattern. Completeness levels and photometric uncertainties are estimated through simulations. More than 300000 galaxies have been detected in the I band and ~50000 in the z band. Object coordinates are defined within an uncertainty of ~0.2" r.m.s., with respect to GSC 2.2. We reach a 90% average completeness at 23.1 and 22.5mag (Vega) in the I and z bands, respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/379/740
- Title:
- ESO Imaging Survey (EIS)
- Short Name:
- J/A+A/379/740
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents multi-passband optical data obtained from observations of the Chandra Deep Field South (CDF-S), located at RA=03h32m, Dec=-27{deg}48'. The observations were conducted at the ESO/MPG 2.2 m telescope at La Silla using the 8kx8k Wide-Field Imager (WFI). This data set, taken over a period of one year, represents the first field to be completed by the ongoing Deep Public Survey (DPS) being carried out as a part of the ESO Imaging Survey (EIS) project. The paper describes the optical observations, the techniques employed for un-supervised pipeline processing and the general characteristics of the final data set. Image processing has been performed using multi-resolution image decomposition techniques adapted to the EIS pipeline. The automatic processing steps include standard de-bias and flat-field, automatic removal of satellite tracks, de-fringing/sky-subtraction, image stacking/mosaicking and astrometry. Stacking of dithered images is carried out using pixel-based astrometry which enables the efficient removal of cosmic rays and image defects, yielding remarkably clean final images. The final astrometric calibration is based on a pre-release of the GSC-II catalog and has an estimated intrinsic accuracy of la 0.10 arcsec, with all passbands sharing the same solution. The data are taken in six different filters (U'UBVRI), cover an area of about 0.25 square degrees, and reach the 5{sigma} limiting magnitudes of U'_AB_=26.0, U_AB_=25.7, B_AB_=26.4, V_AB_=25.4, R_AB_=25.5 and I_AB_=24.7 mag, as measured within a 2xFWHM aperture. The optical data covers an area of ~0.1 square degree for which moderately deep observations in two near-infrared bands are also available, reaching 5{sigma} limiting magnitudes of J_AB_~23.4 and K_AB_~22.6. The current optical/infrared data also fully encompass the region of the deep X-ray observations recently completed by the Chandra telescope. The optical data presented here, as well as the infrared data released earlier, are publicly available world-wide in the form of fully calibrated pixel and associated weight maps and source lists extracted in each passband. These data can be requested through the URL ``http://www.eso.org/eis''. Based on observations collected at the European Southern Observatory, La Silla, Chile within program ESO 164.O-O561.
- ID:
- ivo://CDS.VizieR/J/A+AS/137/75
- Title:
- ESO Imaging Survey. IV.
- Short Name:
- J/A+AS/137/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents preliminary lists of potentially interesting point-like sources extracted from multicolour data obtained for a 1.7 square degree region near the South Galactic Pole. The region has been covered by the ESO Imaging Survey (EIS) in B, V and I and offers a unique combination of area and depth. These lists, containing a total of 330 objects nearly all brighter than I~21.5, over 1. 27 square degrees (after removing some bad regions), are by-products of the process of verification and quality control of the object catalogs being produced. Among the colour selected targets are candidate very low mass stars/brown dwarfs (54), white-dwarfs (32), and quasars (244). In addition, a probable fast moving asteroid was identified. The objects presented here are natural candidates for follow-up spectroscopic observations and illustrate the usefulness of the EIS data for a broad range of science and for providing possible samples for the first year of the VLT.
497. ESO Slice Project
- ID:
- ivo://CDS.VizieR/J/A+AS/130/323
- Title:
- ESO Slice Project
- Short Name:
- J/A+AS/130/323
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO Slice Project (ESP) is a galaxy redshift survey in a region near the South Galactic Pole (see Vettolani et al., 1997A&A...325..954V; Zucca et al., 1997A&A...326..477Z). It extends over a strip 22(RA)x1(DEC) square degrees, plus a nearby area of 5x1 square degrees, 5 degrees west of the main strip. The right ascension limits are 22h30m and 01h20m, at a mean declination of -40{deg}15' (B1950). We have covered this region with a regular grid of adjacent circular fields, with a diameter of 32arcmin each, corresponding to the field of view of the multifiber spectrograph OPTOPUS at the 3.6m ESO telescope. The total solid angle of the spectroscopic survey is 23.2 square degrees. The galaxy catalogue has been extracted from the Edinburgh-Durham Southern Galaxy catalogue (Heydon-Dumbleton et al., 1989MNRAS.238..379H) which has been obtained from COSMOS (MacGillivray & Stobie, 1984VA.....27..433M) scans of SERC J survey plates. The number of objects in the photometric ESP sample is 4487. The spectroscopic survey is about 85% complete to the limiting magnitude bJ=19.4, and consists of 3342 galaxies + 1 QSO with redshift determination. The ESP survey is intermediate between shallow, wide angle samples and very deep, one--dimensional pencil beams. Table 2 lists the fields observed with OPTOPUS and their properties: the numbers listed in this table can be used to compute the redshift completeness of each fields, following eq.(2) of the paper. Table 3 provides the catalogue, with galaxies sorted in right ascension. The catalogue with additional information and updates can also be found at the following URL: http://boas5.bo.astro.it/~cappi/esokp.html
- ID:
- ivo://CDS.VizieR/VII/34C
- Title:
- ESO/Uppsala Survey of the ESO(B) Atlas
- Short Name:
- VII/34C
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The survey is a joint project undertaken by the European Southern Observatory (ESO) and the Uppsala Observatory to provide a systematic and homogeneous search of the ESO(B) Atlas (also known as the Quick Blue Survey). The ESO(B) Atlas, taken with the ESO 1-m Schmidt telescope at La Silla, Chile, covers 606 fields from -90 to -20 degrees of declination. The fields are similar in size and scale to those of the Palomar Observatory Sky Survey. Unsensitized IIa-O plates and a 2-mm GG385 filter were used to give a passband similar to the Johnson B color. The actual search was conducted at the Uppsala Observatory and resulted in a list of nonstellar objects including all NGC and IC galaxies between -20 and -30 degrees declination, all galaxies down to a limiting diameter of 1.0 arcmin, all disturbed galaxies as faint as possible, all star clusters in the Catalog of Star Clusters and Associations (Alter et al. 1970) and smaller and fainter clusters if recognizable and all planetary nebulae listed in the available catalogs. The catalog includes coordinates, identifications, diameters, position angles, morphological types, classifications, magnitudes, colors, and radial velocities.
- ID:
- ivo://CDS.VizieR/J/A+A/629/A80
- Title:
- ESPRESSO blind RV exoplanet survey catalog
- Short Name:
- J/A+A/629/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- One of the main scientific drivers for ESPRESSO, Echelle SPectrograph, is the detection and characterization of Earth-class exoplanets. With this goal in mind, the ESPRESSO guaranteed time observations (GTO) Catalog identifies the best target stars for a blind search for the radial velocity (RV) signals caused by Earth-class exoplanets. Using the most complete stellar catalogs available, we screened for the most suitable G, K, and M dwarf stars for the detection of Earth-class exoplanets with ESPRESSO. For most of the stars, we then gathered high-resolution spectra from new observations or from archival data. We used these spectra to spectroscopically investigate the existence of any stellar binaries, both bound or background stars. We derived the activity level using chromospheric activity indexes using log (R'_HK_), as well as the projected rotational velocity vsini. For the cases where planet companions are already known, we also looked at the possibility that additional planets may exist in the host's habitable zone using dynamical arguments. We estimated the spectroscopic contamination level, vsini, activity, stellar parameters and chemical abundances for 249 of the most promising targets. Using these data, we selected 45 stars that match our criteria for detectability of a planet like Earth. The stars presented and discussed in this paper constitute the ESPRESSO GTO catalog for the RV blind search for Earth-class planets. They can also be used for any other work requiring a detailed spectroscopic characterization of stars in the solar neighborhood.
- ID:
- ivo://CDS.VizieR/J/ApJ/666/674
- Title:
- ESSENCE supernova survey
- Short Name:
- J/ApJ/666/674
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the implementation and optimization of the ESSENCE supernova survey, which we have undertaken to measure the dark energy equation-of-state parameter, w=P/({rho}c^2^). We present a method for optimizing the survey exposure times and cadence to maximize our sensitivity to w for a given fixed amount of telescope time. For our survey on the CTIO 4m telescope, measuring the luminosity distances and redshifts for supernovae at modest redshifts (z~0.5+/-0.2) is optimal for determining w. We describe the data analysis pipeline based on using reliable and robust image subtraction to find supernovae automatically and in nearly real time.
