<i>Gaia</i>Data Release 2

Cropper, Mark; Katz, David; Sartoretti, Paola; Prusti, T.; Bruijne, J. H. J. de; Chassat, F.; Charvet, P.; Boyadjian, J.; Perryman, M. A. C.; Sarri, G.; Garé, P.; Erdmann, Matthias; Munari, U.; Zwitter, T.; Wilkinson, M. I.; Arenou, Frédéric; Vallenari, A.; Gómez, A.; Panuzzo, P.; Seabroke, G. M.; Prieto, C. Allende; Benson, K.; Marchal, Olivier; Huckle, H. E.; Smith, M.; Dolding, C.; Janßen, K.; Viala, Y.; Blomme, R.; Baker, S. G.; Boudreault, S.; Crifo, F.; Soubiran, C.; Frémat, Y.; Jasniewicz, G.; Guerrier, A.; Guy, L. P.; Turon, C.; Jean-Antoine-Piccolo, A.; Thévenin, F.; David, M.; Gosset, Éric; Damerdji, Y.

doi:10.1051/0004-6361/201832763

Cited by 212 publications

(172 citation statements)

References 23 publications

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“…However, for many binaries spectroscopic follow-up may not be required. Over its five-year nominal lifetime, Gaia takes an average of 40 separate radial velocity measurements of every star with G 16 using its radial velocity spectrometer (although note that only the integrated spectra will be useful for stars this faint; epoch radial velocities with reasonable signal-to-noise require stars somewhat brighter; Cropper et al 2018). The precision of these radial velocity observations depend on both a given star's magnitude and its stellar type (late-type stars, which have more spectral lines, tend to be better measured), but may be <1 km s −1 .…”

Section: Radial Velocities and An Extended Gaia Missionmentioning

confidence: 99%

Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia

Andrews

Breivik

Chatterjee³

2019

ApJ

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In astrometric binaries, the presence of a dark, unseen star can be inferred from the gravitational pull it induces on its luminous binary companion. While the orbit of such binaries can be characterized with precise astrometric measurements, constraints made from astrometry alone are not enough to measure the component masses. In this work, we determine the precision with which Gaia can astrometrically measure the orbits and -with additional observations -the component masses, for luminous stars hosting hidden companions. Using realistic mock Gaia observations, we find that Gaia can precisely measure the orbits of binaries hosting hidden brown-dwarfs out to tens of pc and hidden white dwarf and neutron star companions at distances as far as several hundred pc. Heavier black hole companions may be measured out to 1 kpc or farther. We further determine how orbital period affects this precision, finding that Gaia can characterize orbits with periods as short as 10 days and as long as a few 10 3 days, with the best measured orbits having periods just short of Gaia's mission lifetime. Extending Gaia's nominal five-year mission lifetime by an additional five years not only allows for the measurement of longer period orbits, but those longer period binaries can be seen at even greater distances.

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Section: Radial Velocities and An Extended Gaia Missionmentioning

confidence: 99%

Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia

Andrews

Breivik

Chatterjee³

2019

ApJ

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“…Galactic archaeology is at present being propelled by a number of completed or ongoing large-scale spectroscopic surveys: e.g. RAVE (Steinmetz et al 2006), SEGUE (Yanny et al 2009), LAMOST Zhao et al 2012), Gaia-ESO (Gilmore et al 2012), GALAH (De Silva et al 2015), APOGEE (Majewski et al 2017), and the Gaia Radial Velocity Spectrometer (Cropper et al 2018); as well as email: mxiang@mpia.de * Hubble fellow upcoming surveys such as SDSS-V (Kollmeier et al 2017), 4MOST (Feltzing et al 2018;de Jong et al 2019), and WEAVE (Dalton et al 2014). These spectroscopic surveys, combined with the astrometric and photometric information from the Gaia mission (Gaia Collaboration et al 2016Collaboration et al , 2018, make it possible for us to obtain precise and accurate information for millions of stars in phase space or orbit space, along with estimates of age, mass, metallicity, and abundances for many elements, providing unprecedented opportunities to unravel the assemblage and evolution history of our Galaxy (see e.g., Rix & Bovy 2013;Ting, Conroy & Goodman 2015;Xiang et al 2017aXiang et al , 2018Frankel et al 2018;Bland-Hawthorn et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Abundance Estimates for 16 Elements in 6 Million Stars from LAMOST DR5 Low-Resolution Spectra

Xiang¹,

Ting²,

Rix³

et al. 2019

ApJS

198

243

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We present the determination of stellar parameters and individual elemental abundances for 6 million stars from ∼8 million low-resolution (R ∼ 1800) spectra from LAMOST DR5. This is based on a modeling approach that we dub T he Data-Driven P ayne (DD-P ayne), which inherits essential ingredients from both The Payne (Ting et al. 2019) and T he Cannon (Ness et al. 2015). It is a data-driven model that incorporates constraints from theoretical spectral models to ensure the derived abundance estimates are physically sensible. Stars in LAMOST DR5 that are in common with either GALAH DR2 or APOGEE DR14 are used to train a model that delivers stellar parameters (T eff , log g, V mic ) and abundances for 16 elements (C, N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Ba) when applied to LAMOST spectra. Cross-validation and repeat observations suggest that, for S/N pix ≥ 50, the typical internal abundance precision is 0.03-0.1 dex for the majority of these elements, with 0.2-0.3 dex for Cu and Ba, and the internal precision of T eff and log g is better than 30 K and 0.07 dex, respectively. Abundance systematics at the ∼0.1 dex level are present in these estimates, but are inherited from the high-resolution surveys' training labels. For some elements, GALAH provides more robust training labels, for others, APOGEE. We provide flags to guide the quality of the label determination and to identify binary/multiple stars in LAMOST DR5. The abundance catalogs are publicly accessible via http://dr5.lamost.org/doc/vac.

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“…Gaia Data Release 2 (Gaia DR2) was released on 25 April 2018, based on 22 months of observations made between 25 July 2014 to 23 May 2016. Gaia DR2 includes the position, parallax, and proper motion measurements (Gaia Collaboration et al 2018a), red and blue photometric data for about 1.3 billion stars (Evans et al 2018) and radial velocity values of about 7 million stars (Cropper et al 2018).…”

Section: Data Analysis With Gaia Dr2mentioning

confidence: 99%

Analysis of Membership Probability in Nearby Young Moving Groups with Gaia DR2

Ujjwal

Kartha

Mathew

et al. 2020

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We analyze the membership probability of young stars belonging to nearby moving groups with Gaia DR2 data. The sample of 1429 stars were identified from 'The Catalog of Suspected Nearby Young Moving Group Stars'. Good-quality parallax and proper motion values were retrieved for 890 stars from Gaia DR2 database. The analysis for membership probability is performed in the framework of LACEwING algorithm. From the analysis it is confirmed that 279 stars do not belong to any of the known moving groups. We estimated the U, V, W space velocity values for 250 moving group members, which were found to be more accurate than previous values listed in the literature. The velocity ellipses of all the moving groups are well constrained within the "good box", a widely used criterion to identify moving group members. The age of moving group members are uniformly estimated from the analysis of Gaia Color-Magnitude Diagram with MIST isochrones. We found a spread in the age distribution of stars belonging to some moving groups, which needs to be understood from further studies.

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GaiaData Release 2

Cited by 212 publications

References 23 publications

Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia

Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia

Abundance Estimates for 16 Elements in 6 Million Stars from LAMOST DR5 Low-Resolution Spectra

Analysis of Membership Probability in Nearby Young Moving Groups with Gaia DR2

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