COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses. XII. Time delays of the doubly lensed quasars SDSS J1206+4332 and HS 2209+1914
| Autor: | E. Eulaers, Georges Meylan, Sh. A. Ehgamberdiev, Frederic Courbin, H. Van Winckel, C. S. Stalin, I. M. Asfandiyarov, S. Rathna Kumar, Malte Tewes, Pierre Magain, Tushar P. Prabhu |
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| Rok vydání: | 2013 |
| Předmět: |
Physics
Time delays Cosmology and Nongalactic Astrophysics (astro-ph.CO) 010308 nuclear & particles physics gravitational lensing: strong quasars: individual: HS 2209+1914 FOS: Physical sciences Astronomy and Astrophysics Quasar Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Light curve 01 natural sciences Photometry (optics) Gravitation Space and Planetary Science Error bar 0103 physical sciences Deconvolution cosmological parameters 010303 astronomy & astrophysics quasars: individual: SDSS J1206+4332 Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Astronomy & Astrophysics |
| DOI: | 10.1051/0004-6361/201321140 |
| Popis: | Aims. Within the framework of the COSMOGRAIL collaboration we present 7- and 8.5-year-long light curves and time-delay estimates for two gravitationally lensed quasars: SDSS J1206+4332 and HS 2209+1914. Methods. We monitored these doubly lensed quasars in the R-band using four telescopes: the Mercator, Maidanak, Himalayan Chandra, and Euler Telescopes, together spanning a period of 7 to 8.5 observing seasons from mid-2004 to mid-2011. The photometry of the quasar images was obtained through simultaneous deconvolution of these data. The time delays were determined from these resulting light curves using four very different techniques: a dispersion method, a spline fit, a regression difference technique, and a numerical model fit. This minimizes the bias that might be introduced by the use of a single method. Results. The time delay for SDSS J1206+4332 is Delta_t AB = 111.3 +/- 3 days with A leading B, confirming a previously published result within the error bars. For HS 2209+1914 we present a new time delay of Delta_t BA = 20.0 +/- 5 days with B leading A. Conclusions. The combination of data from up to four telescopes have led to well-sampled and nearly 9-season-long light curves, which were necessary to obtain these results, especially for the compact doubly lensed quasar HS 2209+1914. Comment: 10 pages, 10 figures, 6 tables |
| Databáze: | OpenAIRE |
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