C. Ducourant
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View article: Semi-Supervised Learning for Lensed Quasar Detection
Semi-Supervised Learning for Lensed Quasar Detection Open
Lensed quasars are key to many areas of study in astronomy, offering a unique probe into the intermediate and far universe. However, finding lensed quasars has proved difficult despite significant efforts from large collaborations. These c…
View article: <i>Gaia</i> GraL: <i>Gaia</i> gravitational lens systems
<i>Gaia</i> GraL: <i>Gaia</i> gravitational lens systems Open
Aims. Quasar strong gravitational lenses are important tools for putting constraints on the dark matter distribution, dark energy contribution, and the Hubble-Lemaître parameter. We aim to present a new supervised machine learning-based me…
View article: Discovery of a dormant 33 solar-mass black hole in pre-release <i>Gaia</i> astrometry
Discovery of a dormant 33 solar-mass black hole in pre-release <i>Gaia</i> astrometry Open
Context. Gravitational waves from black-hole (BH) merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models – and also…
View article: <i>Gaia</i>Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars
<i>Gaia</i>Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars Open
Context . Strongly lensed quasars are fundamental sources for cosmology. The Gaia space mission covers the entire sky with the unprecedented resolution of 0.18″ in the optical, making it an ideal instrument to search for gravitational lens…
View article: <i>Gaia</i> GraL: <i>Gaia</i> DR2 gravitational lens systems – VIII. A radio census of lensed systems
<i>Gaia</i> GraL: <i>Gaia</i> DR2 gravitational lens systems – VIII. A radio census of lensed systems Open
We present radio observations of 24 confirmed and candidate strongly lensed quasars identified by the Gaia Gravitational Lenses working group. We detect radio emission from eight systems in 5.5 and 9 GHz observations with the Australia Tel…
View article: GraL Spectroscopic Identification of Multiply Imaged Quasars
GraL Spectroscopic Identification of Multiply Imaged Quasars Open
Gravitational lensing is one of the most efficient tools for studying the Universe. However, spectral confirmation of such sources necessitates thorough calibration. This paper discusses the spectral extraction technique for the case where…
View article: GraL spectroscopic identification of multiply imaged quasars
GraL spectroscopic identification of multiply imaged quasars Open
Gravitational lensing is proven to be one of the most efficient tools for studying the Universe. The spectral confirmation of such sources requires extensive calibration. This paper discusses the spectral extraction technique for the case …
View article: Gaia GraL: Gaia DR2 Gravitational Lens Systems. VIII. A radio census of lensed systems
Gaia GraL: Gaia DR2 Gravitational Lens Systems. VIII. A radio census of lensed systems Open
We present radio observations of 24 confirmed and candidate strongly lensed quasars identified by the Gaia Gravitational Lenses (GraL) working group. We detect radio emission from 8 systems in 5.5 and 9 GHz observations with the Australia …
View article: Gaia Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars
Gaia Focused Product Release: A catalogue of sources around quasars to search for strongly lensed quasars Open
Context. Strongly lensed quasars are fundamental sources for cosmology. The Gaia space mission covers the entire sky with the unprecedented resolution of $0.18$" in the optical, making it an ideal instrument to search for gravitational len…
View article: Gaia Focused Product Release: Sources from Service Interface Function image analysis -- Half a million new sources in omega Centauri
Gaia Focused Product Release: Sources from Service Interface Function image analysis -- Half a million new sources in omega Centauri Open
Gaia's readout window strategy is challenged by very dense fields in the sky. Therefore, in addition to standard Gaia observations, full Sky Mapper (SM) images were recorded for nine selected regions in the sky. A new software pipeline exp…
View article: Gaia Focused Product Release: Radial velocity time series of long-period variables
Gaia Focused Product Release: Radial velocity time series of long-period variables Open
The third Gaia Data Release (DR3) provided photometric time series of more than 2 million long-period variable (LPV) candidates. Anticipating the publication of full radial-velocity (RV) in DR4, this Focused Product Release (FPR) provides …
View article: <i>Gaia</i> Focused Product Release: Sources from Service Interface Function image analysis
<i>Gaia</i> Focused Product Release: Sources from Service Interface Function image analysis Open
Context. Gaia ’s readout window strategy is challenged by very dense fields in the sky. Therefore, in addition to standard Gaia observations, full Sky Mapper (SM) images were recorded for nine selected regions in the sky. A new software pi…
View article: <i>Gaia</i>Data Release 3
<i>Gaia</i>Data Release 3 Open
Context. Gaia Data Release 3 ( Gaia DR3) time series data may contain spurious signals related to the time-dependent scan angle. Aims. We aim to explain the origin of scan-angle-dependent signals and how they can lead to spurious periods, …
View article: Gaia Data Release 3: Gaia scan-angle dependent signals and spurious periods
Gaia Data Release 3: Gaia scan-angle dependent signals and spurious periods Open
Context: Gaia DR3 time series data may contain spurious signals related to the time-dependent scan angle. Aims: We aim to explain the origin of scan-angle dependent signals and how they can lead to spurious periods, provide statistics to i…
View article: Shape, alignment, and mass distribution of baryonic and dark-matter\n halos in one EAGLE simulation
Shape, alignment, and mass distribution of baryonic and dark-matter\n halos in one EAGLE simulation Open
Accurate knowledge of the morphology of halos and its evolution are key\nconstraints on the galaxy formation model as well as a determinant parameter of\nthe strong-lensing phenomenon. Using the cosmological hydrodynamic simulation,\nthe E…
View article: <i>Gaia</i>Data Release 3
<i>Gaia</i>Data Release 3 Open
Context. The Gaia DR3 catalogue contains, for the first time, about 800 000 solutions with either orbital elements or trend parameters for astrometric, spectroscopic, and eclipsing binaries, and combinations of these three. Aims. With this…
View article: Gaia Data Release 3: Summary of the content and survey properties
Gaia Data Release 3: Summary of the content and survey properties Open
We present the third data release of the European Space Agency's Gaia mission, GDR3. The GDR3 catalogue is the outcome of the processing of raw data collected with the Gaia instruments during the first 34 months of the mission by the Gaia …
View article: <i>Gaia</i>Data Release 3
<i>Gaia</i>Data Release 3 Open
Context.Gaia Data Release 3 (DR3) provides a wealth of new data products for the astronomical community to exploit, including astrophysical parameters for half a billion stars. In this work, we demonstrate the high quality of these data pr…
View article: <i>Gaia</i> Data Release 3
<i>Gaia</i> Data Release 3 Open
Context. With the most recent Gaia data release, the number of sources with complete 6D phase space information (position and velocity) has increased to well over 33 million stars, while stellar astrophysical parameters are provided for mo…
View article: <i>Gaia</i>Data Release 3
<i>Gaia</i>Data Release 3 Open
Context. The Gaia mission of the European Space Agency (ESA) has been routinely observing Solar System objects (SSOs) since the beginning of its operations in August 2014. The Gaia data release three (DR3) includes, for the first time, the…
View article: <i>Gaia</i>Data Release 3
<i>Gaia</i>Data Release 3 Open
Context. The motion of stars has been used to reveal details of the complex history of the Milky Way, in constant interaction with its environment. Nevertheless, to reconstruct the Galactic history puzzle in its entirety, the chemo-physica…
View article: <i>Gaia</i> Data Release 3
<i>Gaia</i> Data Release 3 Open
Context. Diffuse interstellar bands (DIBs) are common interstellar absorption features in spectroscopic observations but their origins remain unclear. DIBs play an important role in the life cycle of the interstellar medium (ISM) and can a…
View article: <i>Gaia</i> Data Release 3
<i>Gaia</i> Data Release 3 Open
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…
View article: <i>Gaia</i>Data Release 3
<i>Gaia</i>Data Release 3 Open
Context. The third Gaia data release provides photometric time series covering 34 months for about 10 million stars. For many of those stars, a characterisation in Fourier space and their variability classification are also provided. This …
View article: <i>Gaia</i> Data Release 3
<i>Gaia</i> Data Release 3 Open
Context. We present the third data release of the European Space Agency’s Gaia mission, Gaia DR3. This release includes a large variety of new data products, notably a much expanded radial velocity survey and a very extensive astrophysical…
View article: <i>Gaia</i> Early Data Release 3
<i>Gaia</i> Early Data Release 3 Open
Context. Gaia -CRF3 is the celestial reference frame for positions and proper motions in the third release of data from the Gaia mission, Gaia DR3 (and for the early third release, Gaia EDR3, which contains identical astrometric results). …
View article: Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars
Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars Open
We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 ≲ z ≲ 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3–8.0 keV fluxes F 0.3−8.0 ≳ 5 ×10 −14 erg cm −2 s −1 . M…
View article: Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars
Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars Open
We present XMM-Newton X-ray observations of nine confirmed lensed quasars at $1 \lesssim z \lesssim 3$ identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3--8.0 keV fluxes $F_{0.3-8.0} \gtrsim 5 …
View article: Gaia GraL: Gaia DR2 Gravitational Lens Systems. VI. Spectroscopic Confirmation and Modeling of Quadruply Imaged Lensed Quasars
Gaia GraL: Gaia DR2 Gravitational Lens Systems. VI. Spectroscopic Confirmation and Modeling of Quadruply Imaged Lensed Quasars Open
Combining the exquisite angular resolution of Gaia with optical light curves and WISE photometry, the Gaia Gravitational Lenses group (GraL) uses machine-learning techniques to identify candidate strongly lensed quasars, and has confirmed …
View article: Gaia Data Release 2. Observations of solar system objects
Gaia Data Release 2. Observations of solar system objects Open
Context. The Gaia spacecraft of the European Space Agency (ESA) has been securing observations of solar system objects (SSOs) since the beginning of its operations. Data Release 2 (DR2) contains the observations of a selected sample of 14,…