Flux and color variations of the doubly imaged quasar UM673

Ricci, D.; Elyiv, A.; Finet, F.; Wertz, O.; Alsubai, K.; Anguita, T.; Bozza, V.; Browne, P.; Burgdorf, M.; Calchi Novati, S.; Dodds, P.; Dominik, M.; Dreizler, S.; Gerner, T.; Glitrup, M.; Grundahl, F.; Hardis, S.; Harpsøe, K.; Hinse, T. C.; Hornstrup, A.; Hundertmark, M.; Jørgensen, U. G.; Kains, N.; Kerins, E.; Liebig, C.; Maier, G.; Mancini, L.; Masi, G.; Mathiasen, M.; Penny, M.; Proft, S.; Rahvar, S.; Scarpetta, G.; Sahu, K.; Schäfer, S.; Schönebeck, F.; Schmidt, R.; Skottfelt, J.; Snodgrass, C.; Southworth, J.; Thöne, C. C.; Wambsganss, J.; Zimmer, F.; Zub, M.; Surdej, J.

Abstract

Aims. With the aim of characterizing the flux and color variations of the multiple components of the gravitationally lensed quasar UM673 as a function of time, we have performed multiepoch and multiband photometric observations with the Danish telescope at the La Silla Observatory.

Methods. The observations were carried out in the VRi spectral bands during four seasons (2008–2011). We reduced the data using the point spread function photometric technique as well as aperture photometry.

Results. Our results show for the brightest lensed component some significant decrease in flux between the first two seasons (+ 0.09/+ 0.11/+ 0.05 mag) and a subsequent increase during the following ones (− 0.11/− 0.11/− 0.10 mag) in the V/R/i spectral bands, respectively. Comparing our results with previous studies, we find smaller color variations between these seasons as compared with previous ones. We also separate the contribution of the lensing galaxy from that of the fainter and close lensed component.

Citation

Ricci, D., Elyiv, A., Finet, F., Wertz, O., Alsubai, K., Anguita, T., …Surdej, J. (2013). Flux and color variations of the doubly imaged quasar UM673. Astronomy & Astrophysics, 551, Article A104. https://doi.org/10.1051/0004-6361/201118755

• Journal Article Type: Article
• Acceptance Date: Jan 31, 2013
• Online Publication Date: Mar 1, 2013
• Publication Date: 2013-03
• Deposit Date: Jun 15, 2023
• Journal: Astronomy & Astrophysics
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 551
• Article Number: A104
• DOI: https://doi.org/10.1051/0004-6361/201118755
• Keywords: Space and Planetary Science; Astronomy and Astrophysics; gravitational lensing: strong / quasars: general / techniques: photometric / quasars: individual: UM673