Context. Multiply imaged gravitationally lensed quasars are among the most interesting and useful observable extragalactic phenomena. Because their study constitutes a unique tool in various fields of astronomy, they are highly sought, but difficult to find. Even in this era of all-sky surveys, discovering them remains a great challenge, with...
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2018 (v1)Journal articleUploaded on: December 4, 2022
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October 2018 (v1)Journal article
Context. 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 (DR2)...
Uploaded on: December 4, 2022 -
2018 (v1)Publication
Tables 4 provides the compiled list of 478 known gravitationally lensed systems (GL), including candidates (each line corresponds to an image of the lense) together with informations from the Gaia DR2 whenever a source was found at less than 0.5 arcsec from the literature's position of the image. (1) Name, (2) ref - bibliographic reference (*...
Uploaded on: December 4, 2022 -
2012 (v1)Journal article
Context. This study has been developed in the framework of the computational simulations that are executed for the preparation of the ESA Gaia astrometric mission.Aims. We focus on describing the objects and characteristics that Gaia will potentially observe without taking into consideration instrumental effects (detection efficiency, observing...
Uploaded on: December 4, 2022 -
2012 (v1)Journal article
International audience
Uploaded on: December 2, 2022 -
2019 (v1)Publication
The Gaia GraL catalogue of clusters consist of 2,058,962 clusters with three components and 70,697 clusters with four components. Each of these clusters satisfied the following conditions: i) Clusters are composed of three or four images in order to provide a sufficient number of constraints for identifying gravitational lens candidates. ii)...
Uploaded on: December 4, 2022 -
2019 (v1)Journal article
Aims: In this work, we aim to provide a reliable list of gravitational lens candidates based on a search performed over the entire Gaia Data Release 2 (Gaia DR2). We also aim to show that the astrometric and photometric information coming from the Gaia satellite yield sufficient insights for supervised learning methods to automatically identify...
Uploaded on: December 4, 2022 -
2019 (v1)Journal article
We report the spectroscopic confirmation and modeling of the quadruply imaged quasar GRAL 113100–441959, the first gravitational lens (GL) to be discovered from a machine learning technique that only relies on the relative positions and fluxes of the observed images without considering colour informations. Follow-up spectra obtained with...
Uploaded on: December 4, 2022 -
May 14, 2019 (v1)Conference paper
Gaia was mainly designed for the study of stars in our Galaxy. However, by continuously scanning the entire sky, it also provides informations on all kind of objects that fall in its fields of view, including extragalactic objects. Amongst these extragalactic sources, quasars stand out to be some of the most peculiar objects that Gaia observe....
Uploaded on: December 4, 2022 -
November 1, 2021 (v1)Journal article
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 over two dozen new strongly lensed quasars from the Gaia Data Release 2. This paper reports on the 12...
Uploaded on: December 4, 2022 -
May 17, 2021 (v1)Publication
The discovery of multiply-imaged gravitationally lensed QSOs is fundamental to many astronomical and cosmological studies. However, these objects are rare and challenging to discover due to requirements of high-angular resolution astrometric, multiwavelength photometric and spectroscopic data. This has limited the number of known systems to a...
Uploaded on: December 4, 2022 -
2017 (v1)Journal article
Context. The first Gaia data release (DR1) delivered a catalogue of astrometry and photometry for over a billion astronomical sources. Within the panoply of methods used for data exploration, visualisation is often the starting point and even the guiding reference for scientific thought. However, this is a volume of data that cannot be...
Uploaded on: December 4, 2022 -
2017 (v1)Journal article
Before the publication of the Gaia Catalogue, the contents of the first data release have undergone multiple dedicated validation tests. These tests aim at analysing in-depth the Catalogue content to detect anomalies, individual problems in specific objects or in overall statistical properties, either to filter them before the public release,...
Uploaded on: December 4, 2022