Concept

Astrométrie

Publications associées (21)

Time-Delay Cosmography: Measuring the Hubble Constant and Other Cosmological Parameters with Strong Gravitational Lensing

Frédéric Courbin, Martin Raoul Robert Millon

Multiply lensed images of a same source experience a relative time delay in the arrival of photons due to the path length difference and the different gravitational potentials the photons travel through. This effect can be used to measure absolute distance ...

Springer2024

Gaia Focused Product Release: Asteroid orbital solution: Properties and assessment

Stephan Morgenthaler, Shuangqing Liao

Context. We report the exploitation of a sample of Solar System observations based on data from the third Gaia Data Release (Gaia DR3) of nearly 157 000 asteroids. It extends the epoch astrometric solution over the time coverage planned for the Gaia DR4, w ...

Les Ulis Cedex A2023

HD 213258: A new rapidly oscillating, super slowly rotating, strongly magnetic Ap star in a spectroscopic binary

Pierre North

We report on HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at seven epochs spanning a time interval slightly sho ...

EDP SCIENCES S A2023

A new step forward in realistic cluster lens mass modelling: analysis of Hubble Frontier Field Cluster Abell S1063 from joint lensing, X-ray, and galaxy kinematics data

Jean-Paul Richard Kneib, Benjamin Yvan Alexandre Clement, Benjamin Emmanuel Nicolas Beauchesne, Mathilde Jauzac, Johan Richard

We present a new method to simultaneously and self-consistently model the mass distribution of galaxy clusters that combines constraints from strong lensing features, X-ray emission, and galaxy kinematics measurements. We are able to successfully decompose ...

Oxford2023

Gaia Data Release 3: The extragalactic content

Shuangqing Liao

The Gaia Galactic survey mission is designed and optimized to obtain astrometry, photometry, and spectroscopy of nearly two billion stars in our Galaxy. Yet as an all-sky multi-epoch survey, Gaia also observes several million extragalactic objects down to ...

2023

Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era

Pierre North

Context. Li is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. Aims. We present the results of a new large Li survey in red giant stars and combine it with surveys from the literature to probe the impa ...

EDP SCIENCES S A2020

Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram

Stephan Morgenthaler, Mikaël Martino, Jean-Marie Petit, Shuangqing Liao

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G less than or similar to 21 mag. Aims. We showcase stellar variability in the Galactic colour-absolute magnitude diagram (CaMD). We focus on pulsatin ...

EDP SCIENCES S A2019

Barium and related stars, and their white-dwarf companions

Pierre North, Shreeya Sushil Shetye

Barium (Ba) dwarfs and CH subgiants are the less evolved analogues of Ba and CH giants. They are F- to G-type main-sequence stars polluted with heavy elements by their binary companions when the companion was on the asymptotic giant branch (AGB). This comp ...

EDP SCIENCES S A2019

Euclid preparation III. Galaxy cluster detection in the wide photometric survey, performance and algorithm selection

Gianluca Castignani, Marina Ricci

Galaxy cluster counts in bins of mass and redshift have been shown to be a competitive probe to test cosmological models. This method requires an efficient blind detection of clusters from surveys with a well-known selection function and robust mass estima ...

EDP Sciences2019

The Dark Energy Survey: Data Release 1

Yi Zhang, Xin Chen, Eduardo Sanchez, Jonathan Andrew Blazek

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 3 yr of DES science operations ...

IOP PUBLISHING LTD2018

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