Gaia GraL

• Verfasst von: Ducourant, Christine [VerfasserIn]
• Verfasst von: Klüter, Jonas [VerfasserIn]
• Verfasst von: Wambsganß, Joachim [VerfasserIn]
• Verfasst von: Bastian, Ulrich [VerfasserIn]
• Titel: Gaia GraL
• Titelzusatz: Gaia DR2 gravitational lens systems; II. The known multiply imaged quasars
• Verf.angabe: C. Ducourant, O. Wertz, A. Krone-Martins, R. Teixeira, J.-F. Le Campion, L. Galluccio, J. Klüter, L. Delchambre, J. Surdej, F. Mignard, J. Wambsganss, U. Bastian, M.J. Graham, S.G. Djorgovski, and E. Slezak
• E-Jahr: 2018
• Jahr: 12 October 2018
• Umfang: 12 S.
• Fussnoten: Gesehen am 26.02.2019
• Titel Quelle: Enthalten in: Astronomy and astrophysics
• Ort Quelle: Les Ulis : EDP Sciences, 1969
• Jahr Quelle: 2018
• Band/Heft Quelle: 618(2018), Artikel-ID A56
• ISSN Quelle: 1432-0746
• DOI: doi:10.1051/0004-6361/201833480
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1588044270

Abstract

Thanks to its spatial resolution, the ESA/<i>Gaia<i/> 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.<i>Aims<i/>. In this paper, we address the detection of the known multiply imaged quasars from the <i>Gaia<i/> Data Release 2 (DR2) and determine the astrometric and photometric properties of the individually detected images found in the <i>Gaia<i/> DR2 catalogue.<i>Methods<i/>. We have compiled an exhaustive list of quasar gravitational lenses from the literature to search for counterparts in the <i>Gaia<i/> DR2. We then analysed the astrometric and photometric properties of these <i>Gaia<i/>’s detections. To highlight the tremendous potential of <i>Gaia<i/> at the sub-milliarcsecond level we finally performed a simple Bayesian modelling of the well-known gravitational lens system HE0435-1223, using <i>Gaia<i/> DR2 and HST astrometry.<i>Results<i/>. From 481 known multiply imaged quasars, 206 have at least one image found in the <i>Gaia<i/> DR2. Among the 44 known quadruply imaged quasars of the list, 29 have at least one image in the <i>Gaia<i/> DR2, 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), eight have three counterparts, eight have two and one has only one. As expected, the modelling of HE0435-1223 shows that the model parameters are significantly better constrained when using <i>Gaia<i/> astrometry compared to HST astrometry, in particular the relative positions of the background quasar source and the centroid of the deflector. The <i>Gaia<i/> sub-milliarcsecond astrometry also significantly reduces the parameter correlations.<i>Conclusions<i/>. Besides providing an up-to-date list of multiply imaged quasars and their detection in the <i>Gaia<i/> DR2, this paper shows that more complex modelling scenarios will certainly benefit from <i>Gaia<i/> sub-milliarcsecond astrometry.