- ID:
- ivo://CDS.VizieR/III/281
- Title:
- Gaia FGK benchmark stars v2.1
- Short Name:
- III/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this era of large spectroscopic surveys of stars of the Milky Way, pipelines need to be tested and validated against a set of well-known stars. The Gaia FGK benchmark stars (GBS) are among the preferred samples of reference stars. They consist of a small but carefully selected sample of stars whose parameters are derived consistently and homogeneously. A series of papers has been published that discuss the definition and evolution of the sample of GBS. Here we summarise this work and provide our current list of stars with associated parameters which are recommended for validation and calibration purposes for stellar surveys.
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- ID:
- ivo://CDS.VizieR/J/A+A/592/A70
- Title:
- Gaia FGK stars: low-metallicities candidates
- Short Name:
- J/A+A/592/A70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have entered an era of large spectroscopic surveys in which we can measure, through automated pipelines, the atmospheric parameters and chemical abundances for large numbers of stars. Calibrating these survey pipelines using a set of "benchmark stars" in order to evaluate the accuracy and precision of the provided parameters and abundances is of utmost importance. The recent proposed set of Gaia FGK benchmark stars has up to five metal-poor stars but no recommended stars within -2.0<[Fe/H]<-1.0dex. However, this metallicity regime is critical to calibrate properly. In this paper, we aim to add candidate Gaia benchmark stars inside of this metal-poor gap. We began with a sample of 21 metal-poor stars which was reduced to 10 stars by requiring accurate photometry and parallaxes, and high-resolution archival spectra. The procedure used to determine the stellar parameters was similar to the previous works in this series for consistency. The difference was to homogeneously determine the angular diameter and effective temperature (Teff) of all of our stars using the Infrared Flux Method utilizing multi-band photometry. The surface gravity (logg) was determined through fitting stellar evolutionary tracks. The [Fe/H] was determined using four different spectroscopic methods fixing the Teff and logg from the values determined independent of spectroscopy.
- ID:
- ivo://CDS.VizieR/J/A+A/583/A59
- Title:
- Gaia-FUN-SSO network. Apophis campaign
- Short Name:
- J/A+A/583/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astrometric observations performed by the Gaia Follow-Up Network for Solar System Objects (Gaia-FUN-SSO) play a key role in ensuring that moving objects first detected by ESA's Gaia mission remain recoverable after their discovery. An observation campaign on the potentially hazardous asteroid (99942) Apophis was conducted during the asteroid's latest period of visibility, from 12/21/2012 to 5/2/2013, to test the coordination and evaluate the overall performance of the Gaia-FUN-SSO . The 2732 high quality astrometric observations acquired during the Gaia-FUN-SSO campaign were reduced with the Platform for Reduction of Astronomical Images Automatically (PRAIA), using the USNO CCD Astrograph Catalogue 4 (UCAC4, Cat. I/322) as a reference. The astrometric reduction process and the precision of the newly obtained measurements are discussed. We compare the residuals of astrometric observations that we obtained using this reduction process to data sets that were individually reduced by observers and accepted by the Minor Planet Center.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A165
- Title:
- Gaia GraL. III. New lensed systems
- Short Name:
- J/A+A/622/A165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Gaia GraL catalogue of clusters is composed of 2,129,659 clusters consisting of three or four stationary sources from Gaia DR2. Each cluster is assigned a discriminant value, called the extremely randomized trees probability, that reflects its ability to be matched to the image positions and relative magnitudes produced through simulations of gravitational lens systems.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A56
- Title:
- Gaia GraL. II. Known multiply imaged quasars
- Short Name:
- J/A+A/618/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Thanks to its spatial resolution the ESA/Gaia space mission offers a unique opportunity to discover new multiply-imaged quasars and to study the already known lensed systems at sub-milliarcsecond astrometric precisions. Aims : In this paper, we address the detection of the known multiply-imaged quasars from the Gaia Data Release 2 and determine the astrometric and photometric properties of the individually detected images found in the Gaia DR2 catalogue. We have compiled an exhaustive list of quasar gravitational lenses from the literature to search for counterparts in the Gaia Data Release 2. We then analyze the astrometric and photometric properties of these Gaia's detections. To highlight the tremendous potential of Gaia at the sub-milliarcsecond level we finally perform a simple Bayesian modeling of the well-known gravitational lens system HE0435-1223, using Gaia Data Release 2 and HST astrometry. From 478 known multiply imaged quasars, 200 have at least one image found in the Gaia Data Release 2. Among the 41 known quadruply-imaged quasars of the list, 26 have at least one image in the Gaia Data Release 2, 12 of which are fully detected (2MASX J01471020+4630433, HE 0435-1223, SDSS1004+4112, PG1115+080, RXJ1131-1231, 2MASS J11344050-2103230, 2MASS J13102005-1714579, B1422+231, J1606-2333, J1721+8842, WFI2033-4723, WGD2038-4008), 6 have three counterparts, 7 have two and 1 has only one. As expected, the modeling of HE0435-1223 shows that the model parameters are significantly better constrained when using Gaia astrometry compared to HST astrometry, in particular the relative positions of the background quasar source and the centroid of the deflector. The Gaia sub-milliarcsecond astrometry also significantly reduces the parameter correlations. Besides providing an up-to-date list of multiply imaged quasars and their detection in the Gaia DR2, this paper shows that more complex modeling scenarios will certainly benefit from Gaia sub-milliarcsecond astrometry.
- ID:
- ivo://CDS.VizieR/J/MNRAS/505/1135
- Title:
- Gaia/IPHAS catalogue of Ha-excess sources
- Short Name:
- J/MNRAS/505/1135
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present a catalogue of point-like H{alpha}-excess sources in the Northern Galactic Plane. Our catalogue is created using a new technique that leverages astrometric and photometric information from Gaia to select H{alpha}-bright outliers in the INT Photometric H{alpha} Survey of the Northern Galactic Plane (IPHAS), across the colour-absolute magnitude diagram. To mitigate the selection biases due to stellar population mixing and to extinction, the investigated objects are first partitioned with respect to their positions in the Gaia colour-absolute magnitude space, and in the Galactic coordinates space, respectively. The selection is then performed on both partition types independently. Two significance parameters are assigned to each target, one for each partition type. These represent a quantitative degree of confidence that the given source is a reliable H{alpha}-excess candidate, with reference to the other objects in the corresponding partition. Our catalogue provides two flags for each source, both indicating the significance level of the H{alpha}-excess. By analysing their intensity in the H{alpha} narrow band, 28496 objects out of 7474835 are identified as H{alpha}-excess candidates with a significance higher than 3. The completeness fraction of the H{alpha} outliers selection is between 3% and 5%. The suggested 5sigma conservative cut yields a purity fraction of 81.9%.
- ID:
- ivo://CDS.VizieR/IV/36
- Title:
- Gaia-IPHAS/KIS Value-Added Catalogues
- Short Name:
- IV/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sub-arcsecond cross-match of Gaia DR2 (Cat. I/345) against the INT Photometric H-alpha Survey of the Northern Galactic Plane Data Release 2 (IPHAS DR2, Cat. II/321) and the Kepler-INT Survey (KIS, Cat. J/AJ/144/24). The resulting value-added catalogues (VACs) provide additional precise photometry to the Gaia photometry (r, i and H-alpha for IPHAS, with additional U and g for KIS). In building the catalogue, proper motions given in Gaia DR2 are wound back to match the epochs of IPHAS DR2, thus ensuring high proper motion objects are appropriately cross-matched. The catalogues contain 7927224 and 791071 sources for IPHAS and KIS, respectively. The requirement of >5 sigma parallax detection for every included source means that distances out to 1-1.5kpc are well covered. We define two additional parameters for each catalogued object: (i) fc, a magnitude-dependent tracer of the quality of the Gaia astrometric fit; (ii) fFP, the false-positive rate for parallax measurements determined from astrometric fits of a given quality at a given magnitude. Selection cuts based on these parameters can be used to clean colour-magnitude and colour-colour diagrams in a controlled and justified manner. We provide both full and light versions of the VAC, with VAC-light containing only objects that represent our recommended trade-off between purity and completeness. Uses of the catalogues include the identification of new variable stars in the matched data sets, and more complete identification of H-alpha-excess emission objects thanks to separation of high-luminosity stars from the main sequence.
- ID:
- ivo://CDS.VizieR/J/AJ/160/108
- Title:
- Gaia-Kepler stellar properties catalog. II. Planets
- Short Name:
- J/AJ/160/108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Studies of exoplanet demographics require large samples and precise constraints on exoplanet host stars. Using the homogeneous Kepler stellar properties derived using the Gaia Data Release 2 by Berger et al., we recompute Kepler planet radii and incident fluxes and investigate their distributions with stellar mass and age. We measure the stellar mass dependence of the planet radius valley to be dlogR_p/d_logM_{star}_=0.26_-0.16_^+0.21^, consistent with the slope predicted by a planet mass dependence on stellar mass (0.24-0.35) and core-powered mass loss (0.33). We also find the first evidence of a stellar age dependence of the planet populations straddling the radius valley. Specifically, we determine that the fraction of super-Earths (1-1.8{R_{Earth}_) to sub-Neptunes (1.8-3.5R_{Earth}_) increases from 0.61{+/-}0.09 at young ages (<1Gyr) to 1.00{+/-}0.10 at old ages (>1Gyr), consistent with the prediction by core-powered mass loss that the mechanism shaping the radius valley operates over Gyr timescales. Additionally, we find a tentative decrease in the radii of relatively cool (Fp<150{F}_{Earth}_) sub-Neptunes over Gyr timescales, which suggests that these planets may possess H/He envelopes instead of higher mean molecular weight atmospheres. We confirm the existence of planets within the hot sub-Neptunian "desert" (2.2R_{Earth}_<Rp<3.8R_{Earth}_, Fp>650F_{Earth}_) and show that these planets are preferentially orbiting more evolved stars compared to other planets at similar incident fluxes. In addition, we identify candidates for cool (Fp<20F_{Earth}_) inflated Jupiters, present a revised list of habitable zone candidates, and find that the ages of single and multiple transiting planet systems are statistically indistinguishable.
- ID:
- ivo://CDS.VizieR/J/AJ/159/280
- Title:
- Gaia-Kepler stellar properties catalog.I. KIC stars
- Short Name:
- J/AJ/159/280
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An accurate and precise Kepler Stellar Properties Catalog is essential for the interpretation of the Kepler exoplanet survey results. Previous Kepler Stellar Properties Catalogs have focused on reporting the best-available parameters for each star, but this has required combining data from a variety of heterogeneous sources. We present the Gaia-Kepler Stellar Properties Catalog, a set of stellar properties of 186301 Kepler stars, homogeneously derived from isochrones and broadband photometry, Gaia Data Release 2 parallaxes, and spectroscopic metallicities, where available. Our photometric effective temperatures, derived from g to Ks colors, are calibrated on stars with interferometric angular diameters. Median catalog uncertainties are 112K for Teff, 0.05dex for logg, 4% for R_*_, 7% for M_*_, 13% for {rho}_*_, 10% for L_*_, and 56% for stellar age. These precise constraints on stellar properties for this sample of stars will allow unprecedented investigations into trends in stellar and exoplanet properties as a function of stellar mass and age. In addition, our homogeneous parameter determinations will permit more accurate calculations of planet occurrence and trends with stellar properties.
- ID:
- ivo://CDS.VizieR/J/ApJ/867/L8
- Title:
- Gaia kinematic data of runaway & field OB stars in SMC
- Short Name:
- J/ApJ/867/L8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Gaia Data Release 2 proper motions of field OB stars from the Runaways and Isolated O-Type Star Spectroscopic Survey of the Small Magellanic Cloud (SMC) to study the kinematics of runaway stars. The data reveal that the SMC Wing has a systemic peculiar motion relative to the SMC Bar of (v_{alpha}_,v_{delta}_)=(62+/-7,-18+/-5)km/s and relative radial velocity +4.5+/-5.0km/s. This unambiguously demonstrates that these two regions are kinematically distinct: the Wing is moving away from the Bar, and towards the Large Magellanic Cloud with a 3D velocity of 64+/-10km/s. This is consistent with models for a recent, direct collision between the Clouds. We present transverse velocity distributions for our field OB stars, confirming that unbound runaways comprise on the order of half our sample, possibly more. Using eclipsing binaries and double-lined spectroscopic binaries as tracers of dynamically ejected runaways, and high-mass X-ray binaries (HMXBs) as tracers of runaways accelerated by supernova kicks, we find significant contributions from both populations. The data suggest that HMXBs have lower velocity dispersion relative to dynamically ejected binaries, consistent with the former group corresponding to less energetic supernova kicks that failed to unbind the components. Evidence suggests that our fast runaways are dominated by dynamical, rather than supernova, ejections.