- ID:
- ivo://CDS.VizieR/J/MNRAS/475/193
- Title:
- Foundation Supernova Survey first data release
- Short Name:
- J/MNRAS/475/193
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest component of systematic uncertainties for SN cosmology, and new data are necessary to make progress. We present the motivation, survey design, observation strategy, implementation, and first results for the Foundation Supernova Survey. We are using the Pan-STARRS telescope to obtain photometry for up to 800 SNe Ia at z<~0.1. This strategy has several unique advantages: (1) the Pan-STARRS system is a superbly calibrated telescopic system, (2) Pan-STARRS has observed 3/4 of the sky in grizyP1 making future template observations unnecessary, (3) we have a well-tested data-reduction pipeline, and (4) we have observed ~3000 high-redshift SNe Ia on this system. Here, we present our initial sample of 225 SN Ia grizP1 light curves, of which 180 pass all criteria for inclusion in a cosmological sample. The Foundation Supernova Survey already contains more cosmologically useful SNe Ia than all other published low-redshift SN Ia samples combined. We expect that the systematic uncertainties for the Foundation Supernova Sample will be two to three times smaller than other low-redshift samples. We find that our cosmologically useful sample has an intrinsic scatter of 0.111mag, smaller than other low-redshift samples. We perform detailed simulations showing that simply replacing the current low-redshift SN Ia sample with an equally sized Foundation sample will improve the precision on the dark energy equation-of-state parameter by 35 per cent, and the dark energy figure of merit by 72 per cent.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/830/51
- Title:
- FourStar galaxy evolution survey (ZFOURGE)
- Short Name:
- J/ApJ/830/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The FourStar galaxy evolution survey (ZFOURGE) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date. ZFOURGE covers a total of 400arcmin^2^ in cosmic fields CDFS, COSMOS and UDS, overlapping the CANDELS fields.
- ID:
- ivo://CDS.VizieR/VIII/4
- Title:
- Fourth Cambridge Survey (4C)
- Short Name:
- VIII/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fourth Cambridge Radio Survey (4C) Catalogue contains all survey data from the papers of Pilkington and Scott (1965MmRAS..69..183P) and Gower, Scott and Wills (1967MmRAS..71...49G). These data result from a survey of radio sources between declinations -07 and +80 degrees using the large Cambridge interferometer at 178 MHz. The computerized catalog contains for each source the 4C number, 1950 position, measured flux density, accuracy class, galactic coordinates, and remarks. For some sources miscellaneous brief comments such as cross identifications to the 3C catalog or remarks on contamination from nearby sources are given at the ends of the data records. A flag (*) is included if there are additional remarks in the published catalog.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1872
- Title:
- Fourth VLBA calibrator survey: VCS4
- Short Name:
- J/AJ/131/1872
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the fourth extension to the VLBA Calibrator Survey, containing 258 new sources not previously observed with very long baseline interferometry (VLBI). This survey, based on three 24hr Very Long Baseline Array observing sessions, fills remaining areas on the sky above declination -40{deg} where the calibrator density is less than one source within a 4{deg} radius disk in any given direction. The share of these areas was reduced from 4.6% to 1.9%. Source positions were derived from astrometric analysis of group delays determined at 2.3 and 8.6GHz frequency bands using the Calc/Solve software package. The VCS4 catalog of source positions, plots of correlated flux density versus projected baseline length, contour plots, and fits files of naturally weighted CLEAN images, as well as calibrated visibility function files, are available online at http://vlbi.gsfc.nasa.gov/vcs4 .
- ID:
- ivo://CDS.VizieR/J/AJ/134/1133
- Title:
- Fraction of contact binary trojan asteroids
- Short Name:
- J/AJ/134/1133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an optical light-curve survey of 114 Jovian Trojan asteroids conducted to determine the fraction of contact binaries. Sparse sampling was used to assess the photometric range of the asteroids, and those showing the largest ranges were targeted for detailed follow-up observations. This survey led to the discovery of two Trojan asteroids, (17365) and (29314), displaying large light-curve ranges (~1mag) and long rotation periods (<2rotations/day) consistent with a contact binary nature.
- ID:
- ivo://CDS.VizieR/J/MNRAS/457/4089
- Title:
- Frequency of snowline-region planets
- Short Name:
- J/MNRAS/457/4089
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical analysis of the first four seasons from a 'second-generation' microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg^2^ of the Galactic bulge by the Optical Gravitational Lens Experiment (OGLE), Microlensing Observations in Astrophysics (MOA), and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12 per cent of the events showed a deviation from single-lens microlensing, and for ~one-third of those the anomaly is likely caused by a planetary companion. For each of the 224 events, we have performed numerical ray-tracing simulations to calculate the detection efficiency of possible companions as a function of companion-to-host mass ratio and separation. Accounting for the detection efficiency, we find that 55^+34^_-22_ per cent of microlensed stars host a snowline planet. Moreover, we find that Neptune-mass planets are ~10 times more common than Jupiter-mass planets. The companion-to-host mass-ratio distribution shows a deficit at q~10^-2^, separating the distribution into two companion populations, analogous to the stellar-companion and planet populations, seen in radial-velocity surveys around solar-like stars. Our survey, however, which probes mainly lower mass stars, suggests a minimum in the distribution in the super-Jupiter mass range, and a relatively high occurrence of brown-dwarf companions.
- ID:
- ivo://CDS.VizieR/J/ApJS/227/3
- Title:
- Full spectroscopic data release of the SPT-GMOS
- Short Name:
- J/ApJS/227/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500deg^2^ of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of [OII]{lambda}{lambda}3727, 3729 and H-{delta}, and the 4000{AA} break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m*). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ~20% of the full SPT-SZ sample.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A6
- Title:
- Gaia Catalogue of Nearby Stars - GCNS
- Short Name:
- J/A+A/649/A6
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We produce a clean and well-characterised catalogue of objects within 100 pc of the Sun from the Gaia Early Data Release 3. We characterise the catalogue through comparisons to the full data release, external catalogues, and simulations. We carry out a first analysis of the science that is possible with this sample to demonstrate its potential and best practices for its use. The selection of objects within 100 pc from the full catalogue used selected training sets, machine-learning procedures, astrometric quantities, and solution quality indicators to determine a probability that the astrometric solution is reliable. The training set construction exploited the astrometric data, quality flags, and external photometry. For all candidates we calculated distance posterior probability densities using Bayesian procedures and mock catalogues to define priors. Any object with reliable astrometry and a non-zero probability of being within 100pc is included in the catalogue. We have produced a catalogue of 331312 objects that we estimate contains at least 92% of stars of stellar type M9 within 100pc of the Sun. We estimate that 9% of the stars in this catalogue probably lie outside 100pc, but when the distance probability function is used, a correct treatment of this contamination is possible. We produced luminosity functions with a high signal-to-noise ratio for the main-sequence stars, giants, and white dwarfs. We examined in detail the Hyades cluster, the white dwarf population, and wide-binary systems and produced candidate lists for all three samples. We detected local manifestations of several streams, superclusters, and halo objects, in which we identified 12 members of Gaia Enceladus. We present the first direct parallaxes of five objects in multiple systems within 10pc of the Sun. We provide the community with a large, well-characterised catalogue of objects in the solar neighbourhood. This is a primary benchmark for measuring and understanding fundamental parameters and descriptive functions in astronomy.
- ID:
- ivo://org.gavo.dc/gaia/q/dr1
- Title:
- Gaia Data Release 1 (DR1) gaia_source
- Date:
- 17 Sep 2020 08:07:06
- Publisher:
- The GAVO DC team
- Description:
- This table, corresponding to gaia_source of the full DR1, contains the 1.15 billion objects reliably detected in the first 14 months of Gaia observations. It essentially consists of high-precision positions and magnitudes. The TGAS subset (about 2 million objects observed by both Gaia and Hipparcos) has proper motions and parallaxes. Users are advised to beware strong correlations between the astrometric parameters present for some of the less densely observed objects and the inhomogeneous coverage in this first data release (solution id: 1635378410781933568).
620. Gaia DR2
- ID:
- ivo://CDS.VizieR/I/345
- Title:
- Gaia DR2
- Short Name:
- I/345
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gaia Data Release 2. Summary of the contents and survey properties: We present the second Gaia data release, Gaia DR2, consisting of astrometry, photometry, radial velocities, and information on as- trophysical parameters and variability, for sources brighter than magnitude 21. In addition epoch astrometry and photometry are provided for a modest sample of minor planets in the solar system. A summary of the contents of Gaia DR2 is presented, accompanied by a discussion on the differences with respect to Gaia DR1 and an overview of the main limitations which are still present in the survey. Recommendations are made on the responsible use of Gaia DR2 results. Methods. The raw data collected with the Gaia instruments during the first 22 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into this second data release, which represents a major advance with respect to Gaia DR1 in terms of completeness, performance, and richness of the data products. Gaia DR2 contains celestial positions and the apparent brightness in G for approximately 1.7 billion sources. For 1.3 billion of those sources, parallaxes and proper motions are in addition available. The sample of sources for which variability information is provided is expanded to 0.5 million stars. This data release contains four new elements: broad-band colour information in the form of the apparent brightness in the G_BP_ (330-680nm) and G_RP_ (630-1050nm) bands is available for 1.4 billion sources; median radial velocities for some 7 million sources are presented; for between 77 and 161 million sources estimates are provided of the stellar effective temperature, extinction, reddening, and radius and luminosity; and for a pre-selected list of 14000 minor planets in the solar system epoch astrometry and photometry are presented. Finally, Gaia DR2 also represents a new materialisation of the celestial reference frame in the optical, the Gaia-CRF2, which is the first optical reference frame based solely on extragalactic sources. There are notable changes in the photometric system and the catalogue source list with respect to Gaia DR1, and we stress the need to consider the two data releases as independent. Gaia DR2 represents a major achievement for the Gaia mission, delivering on the long standing promise to provide parallaxes and proper motions for over 1 billion stars, and representing a first step in the availability of complementary radial velocity and source astrophysical information for a sample of stars in the Gaia survey which covers a very substantial fraction of the volume of our galaxy. The catalogue of radial velocity standard stars (Soubiran et al., 2018A&A...616A...7S) The Radial Velocity Spectrometer (RVS) on board of Gaia having no calibration device, the zero point of radial velocities needs to be calibrated with stars proved to be stable at the level of 300m/s during the Gaia observations. A dataset of about 71000 ground-based radial velocity measurements from five high resolution spectrographs has been compiled. A catalogue of 4813 stars was built by combining these individual measurements. The zero point has been established using asteroids. The resulting catalogue has 7 observations per star on average on a typical time baseline of 6 years, with a median standard deviation of 15m/s. A subset of the most stable stars fulfilling the RVS requirements has been used to establish the zero point of the radial velocities provided in Gaia DR2. The stars not used for calibration are used for the RVS data validation.