- ID:
- ivo://CDS.VizieR/J/AJ/142/156
- Title:
- The CSP (DR2): photometry of SNe Ia
- Short Name:
- J/AJ/142/156
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Carnegie Supernova Project (CSP) was a five-year observational survey conducted at Las Campanas Observatory that obtained, among other things, high-quality light curves of ~100 low-redshift Type Ia supernovae (SNe Ia). Presented here is the second data release of nearby SN Ia photometry consisting of 50 objects, with a subset of 45 having near-infrared follow-up observations. Thirty-three objects have optical pre-maximum coverage with a subset of 15 beginning at least five days before maximum light. In the near-infrared, 27 objects have coverage beginning before the epoch of B-band maximum, with a subset of 13 beginning at least five days before maximum. In addition, we present results of a photometric calibration program to measure the CSP optical (uBgVri) bandpasses with an accuracy of ~1%. Finally, we report the discovery of a second SN Ia, SN 2006ot, similar in its characteristics to the peculiar SN 2006bt.
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Search Results
- ID:
- ivo://CDS.VizieR/II/371
- Title:
- The Dark Energy Survey (DES): Data Release 2
- Short Name:
- II/371
- Date:
- 31 Jan 2022
- Publisher:
- CDS
- Description:
- We present the second public data release of the Dark Energy Survey, DES DR2, based on optical/near-infrared imaging by the Dark Energy Camera mounted on the 4m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. DES DR2 consists of reduced single-epoch and coadded images, a source catalog derived from coadded images, and associated data products assembled from 6yr of DES science operations. This release includes data from the DES wide-area survey covering ~5000deg^2^ of the southern Galactic cap in five broad photometric bands, grizY. DES DR2 has a median delivered point-spread function FWHM of g=1.11", r=0.95", i=0.88", z=0.83", and Y=0.90", photometric uniformity with a standard deviation of <3mmag with respect to Gaia DR2 G band, a photometric accuracy of ~11mmag, and a median internal astrometric precision of ~27mas. The median coadded catalog depth for a 1farcs95 diameter aperture at signal-to-noise ratio =10 is g=24.7, r=24.4, i=23.8, z=23.1, and Y=21.7mag. DES DR2 includes ~691 million distinct astronomical objects detected in 10169 coadded image tiles of size 0.534deg^2^ produced from 76217 single-epoch images. After a basic quality selection, benchmark galaxy and stellar samples contain 543 million and 145 million objects, respectively.
- ID:
- ivo://CDS.VizieR/II/357
- Title:
- The Dark Energy Survey (DES): Data Release 1
- Short Name:
- II/357
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the first public data release of the Dark Energy Survey, DES DR1, consisting of reduced single-epoch images, co-added images, co-added source catalogs, and associated products and services assembled over the first 3yr of DES science operations. DES DR1 is based on optical/near-infrared imaging from 345 distinct nights (2013 August to 2016 February) by the Dark Energy Camera (DECam) mounted on the 4m Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. We release data from the DES wide-area survey covering ~5000deg^2^ of the southern Galactic cap in five broad photometric bands, grizY. DES DR1 has a median delivered point-spread function of g=1.12, r=0.96, i=0.88, z=0.84, and Y=0.90" FWHM, a photometric precision of <1% in all bands, and an astrometric precision of 151mas. The median co-added catalog depth for a 1.95" diameter aperture at signal-to-noise ratio (S/N)=10 is g=24.33, r=24.08, i=23.44, z=22.69, and Y=21.44mag. DES DR1 includes nearly 400 million distinct astronomical objects detected in ~10000 co-add tiles of size 0.534deg^2^ produced from ~39000 individual exposures. Benchmark galaxy and stellar samples contain ~310 million and ~80 million objects, respectively, following a basic object quality selection. DES DR1 constitutes the largest photometric data set to date at the achieved depth and photometric precision.
- ID:
- ivo://CDS.VizieR/V/152
- Title:
- The DEBCat detached eclipsing binary catalogue
- Short Name:
- V/152
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Detached eclipsing binary star systems are our primary source of measured physical properties of normal stars. I introduce DEBCat: a catalog of detached eclipsing binaries with mass and radius measurements to the 2% precision necessary to put useful constraints on theoretical models of stellar evolution. The catalog was begun in 2006, as an update of the compilation by Andersen (1991A&ARv...3...91A). It now contains over 195 systems (2017/10/10), and new results are added on appearance in the refereed literature.
- ID:
- ivo://CDS.VizieR/J/ApJ/718/683
- Title:
- The edge of the young Galactic disk
- Short Name:
- J/ApJ/718/683
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we report and discuss the detection of two distant diffuse stellar groups in the third Galactic quadrant. They are composed of young stars, with spectral types ranging from late O to late B, and lie at galactocentric distances between 15 and 20kpc. These groups are located in the area of two cataloged open clusters (VdB-Hagen 04 and Ruprecht 30), projected toward the Vela-Puppis constellations, and within the core of the Canis Major overdensity. Their reddening and distances have been estimated by analyzing their color-color and color-magnitude diagrams, derived from deep UBV photometry. The existence of young star aggregates at such extreme distances from the Galactic center challenges the commonly accepted scenario in which the Galactic disk has a sharp cutoff at about 14kpc from the Galactic center and indicates that it extends to much greater distances (as also supported by the recent detection of CO molecular complexes well beyond this distance). While the groups we find in the area of Ruprecht 30 are compatible with the Orion and Norma-Cygnus spiral arms, respectively, the distant group we identify in the region of VdB-Hagen 04 lies in the external regions of the Norma-Cygnus arm, at a galactocentric distance (~20kpc) where no young stars have been detected so far in the optical.
- ID:
- ivo://CDS.VizieR/J/ApJS/243/5
- Title:
- The ELQS in the PS1 footprint (PS-ELQS)
- Short Name:
- J/ApJS/243/5
- Date:
- 08 Mar 2022 13:10:17
- Publisher:
- CDS
- Description:
- We present the results of the Extremely Luminous Quasar Survey in the 3{pi} survey of the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS; PS1). This effort applies the successful quasar selection strategy of the Extremely Luminous Survey in the Sloan Digital Sky Survey footprint (~12000deg^2^) to a much larger area (~21486deg^2^). This spectroscopic survey targets the most luminous quasars (M_1450_<=-26.5; m_i_<=18.5) at intermediate redshifts (z>=2.8). Candidates are selected based on a near-infrared JKW2 color cut using WISE AllWISE and 2MASS photometry to mainly reject stellar contaminants. Photometric redshifts (z_reg_) and star-quasar classifications for each candidate are calculated from near-infrared and optical photometry using the supervised machine learning technique random forests. We select 806 quasar candidates at z_reg_>=2.8 from a parent sample of 74318 sources. After exclusion of known sources and rejection of candidates with unreliable photometry, we have taken optical identification spectra for 290 of our 334 good PS-ELQS candidates. We report the discovery of 190 new z>=2.8 quasars and an additional 28 quasars at lower redshifts. A total of 44 good PS-ELQS candidates remain unobserved. Including all known quasars at z>=2.8, our quasar selection method has a selection efficiency of at least 77%. At lower declinations, -30<=DEC<=0, we approximately treble the known population of extremely luminous quasars. We provide the PS-ELQS quasar catalog with a total of 592 luminous quasars (m_i_<=18.5, z>=2.8). This unique sample will not only be able to provide constraints on the volume density and quasar clustering of extremely luminous quasars, but also offers valuable targets for studies of the intergalactic medium.
- ID:
- ivo://CDS.VizieR/J/ApJ/863/181
- Title:
- The fifth catalog of LMC Wolf-Rayet stars
- Short Name:
- J/ApJ/863/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We summarize the results of our 4yr survey searching for Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud. Over the course of this survey we have discovered 15 new WR stars and 12 Of-type stars. In this last year we discovered two rare Of-type stars: an O6.5f?p and an O6nfp, in addition to the two new Of?p stars discovered in our first year and the three Onfp stars discovered in our second and third years. However, even more exciting was our discovery of a new type of WR star, ones we are calling WN3/O3s owing to their spectroscopic signatures. We describe the completeness limits of our survey and demonstrate that we are sensitive to weak-lined WRs several magnitudes fainter than any we have discovered, arguing that there is not a population of fainter WRs waiting to be discovered. We discuss the nature of the WN3/O3s, summarizing the results of our extensive spectroscopy and modeling. We also examine the important claim made by others that the WN3/O3s are isolated compared to other massive stars. We find that if we use a more complete sample of reference massive stars, the WN3/O3s show the same spatial distribution as other early WNs, consistent with a common origin. Finally, we use this opportunity to present the "Fifth Catalog of LMC Wolf-Rayet Stars," which includes revised coordinates and updated spectral types for all 154 known LMC WRs.
- ID:
- ivo://CDS.VizieR/J/AJ/155/116
- Title:
- The globular cluster M14.II. Variable stars
- Short Name:
- J/AJ/155/116
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present time-series BVI photometry for the Galactic globular cluster NGC 6402 (M14). The data consist of ~137 images per filter, obtained using the 0.9 and 1.0 m SMARTS telescopes at the Cerro Tololo Inter-American Observatory. The images were obtained during two observing runs in 2006-2007. The image-subtraction package ISIS, along with DAOPHOT II/ALLFRAME, was used to perform crowded-field photometry and search for variable stars. We identified 130 variables, eight of which are new discoveries. The variable star population is comprised of 56 ab-type RR Lyrae stars, 54 c-type RR Lyrae, 6 type II Cepheids, 1 W UMa star, 1 detached eclipsing binary, and 12 long-period variables. We provide Fourier decomposition parameters for the RR Lyrae, and discuss the physical parameters and photometric metallicity derived therefrom. The M14 distance modulus is also discussed, based on different approaches for the calibration of the absolute magnitudes of RR Lyrae stars. The possible presence of second-overtone RR Lyrae in M14 is critically addressed, with our results arguing against this possibility. By considering all of the RR Lyrae stars as members of the cluster, we derive <P_ab_>=0.589 days. This, together with the position of the RR Lyrae stars of both Bailey types in the period-amplitude diagram, suggests an Oosterhoff-intermediate classification for the cluster. Such an intermediate Oosterhoff type is much more commonly found in nearby extragalactic systems, and we critically discuss several other possible indications that may point to an extragalactic origin for this cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/286/444
- Title:
- The globular cluster NGC 6652
- Short Name:
- J/A+A/286/444
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/AJ/156/186
- Title:
- The High Cadence Transit Survey (HiTS)
- Short Name:
- J/AJ/156/186
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The High Cadence Transient Survey (HiTS) aims to discover and study transient objects with characteristic timescales between hours and days, such as pulsating, eclipsing, and exploding stars. This survey represents a unique laboratory to explore large etendue observations from cadences of about 0.1 days and test new computational tools for the analysis of large data. This work follows a fully data science approach, from the raw data to the analysis and classification of variable sources. We compile a catalog of ~15 million object detections and a catalog of ~2.5 million light curves classified by variability. The typical depth of the survey is 24.2, 24.3, 24.1, and 23.8 in the u, g, r, and i bands, respectively. We classified all point-like nonmoving sources by first extracting features from their light curves and then applying a random forest classifier. For the classification, we used a training set constructed using a combination of cross-matched catalogs, visual inspection, transfer/active learning, and data augmentation. The classification model consists of several random forest classifiers organized in a hierarchical scheme. The classifier accuracy estimated on a test set is approximately 97%. In the unlabeled data, 3485 sources were classified as variables, of which 1321 were classified as periodic. Among the periodic classes, we discovered with high confidence one {delta} Scuti, 39 eclipsing binaries, 48 rotational variables, and 90 RR Lyrae, and for the nonperiodic classes, we discovered one cataclysmic variable, 630 QSOs, and one supernova candidate.
