Time delay of SBS 0909+532

Abstract

The time delays between the components of a lensed quasar are basic tools to analyze the expansion of the Universe and the structure of the main lens galaxy halo. In this paper, we focus on the variability and time delay of the double system SBS 0909+532A,B as well as the time behaviour of the field stars. We use VR optical observations of SBS 0909+532A,B and the field stars in 2003. The frames were taken at Calar Alto, Maidanak and Wise observatories, and the VR light curves of the field stars and quasar components are derived from aperture and point-spread function fitting methods. We measure the R-band time delay of the system from the chi-square and dispersion techniques and 1000 synthetic light curves based on the observed records. One nearby field star (SBS 0909+532c) is found to be variable, and the other two nearby field stars are non-variable sources. With respect to the quasar components, the R-band records seem more reliable and are more densely populated than the V-band ones. The observed R-band fluctuations permit a pre-conditioned measurement of the time delay. From the chi-square minimization, if we assume that the quasar emission is observed first in B and afterwards in A (in agreement with basic observations of the system and the corresponding predictions), we obtain a delay of - 45 (+ 1)/(- 11) days (95% confidence interval). The dispersion technique leads to a similar delay range. A by-product of the analysis is the determination of a totally corrected flux ratio in the R band (corrected by the time delay and the contamination due to the galaxy light). Our 95% measurement of this ratio (0.575 +/- 0.014 mag) is in excellent agreement with previous results from contaminated fluxes at the same time of observation.

26 pages, 15 figures, Astronomy and Astrophysics (see also http://www.astro.ulg.ac.be/RPub/Colloques/JENAM/proceedings/proceedings.html - Quasars Section)

References in corpus (37)

• Is There A Cosmological Constant?
• A Robust Determination of the Time Delay in 0957+561A,B and a Measurement of the Global Value of Hubble's Constant
• The Quadruple Gravitational Lens PG1115+080: Time Delays and Models
• Deconvolution with correct sampling
• HST Observations of 10 Two-Image Gravitational Lenses
• What Do Gravitational Lens Time Delays Measure?
• A Determination of H_0 with the CLASS Gravitational Lens B1608+656: III. A Significant Improvement in the Precision of the Time Delay Measurements
• Time delay for the gravitational lens system B0218+357
• The Time Delay in the Gravitational Lens PKS 1830-211
• COSMOGRAIL XVI: Time delays for the quadruply imaged quasar DES J0408-5354 with high-cadence photometric monitoring
• An Optical Time-Delay for the Lensed BAL Quasar HE2149-2745
• Time delay and lens redshift for the doubly imaged BAL quasar SBS1520+530
• Analytic Time Delays and H_0 Estimates for Gravitational Lenses
• The Hamburg/RASS Catalogue of optical identifications. Northern high-galactic latitude ROSAT Bright Source Catalogue X-ray sources
• Detection of the 2175ÅExtinction Feature at z=0.83
• Chandra Observations of QSO 2237+0305
• An optical time-delay estimate for the double gravitational lens system B1600+434
• The edge-on spiral gravitational lens B1600+434
• The time delay of the quadruple quasar RX J0911.4+0551
• The elliptical colour-magnitude relation as a discriminant between the monolithic and merger paradigms: the importance of progenitor bias
• An optical time delay for the double gravitational lens system FBQ 0951+2635
• A Keck Survey of Gravitational Lens Systems: I. Spectroscopy of SBS 0909+532, HST 1411+5211, and CLASS B2319+051
• Determination of time delay from the gravitational lens B1422+231
• Time delay measurement of the lensed quasar HE1104-1805
• The gravitational lens MG0414+0534: a link between red galaxies and dust
• The Radio Wavelength Time Delay of Gravitational Lens 0957+561
• X-ray Observations of Gravitationally Lensed Quasars; Evidence for a Hidden Quasar Population
• BVRI photometry of QSO 0957+561A, B: Observations, new reduction method and time delay
• The Double Quasar HE1104-1805: a case study for time delay determination with poorly sampled lightcurves
• XMM-Newton observations of high-luminosity radio-quiet QSOs
• New aperture photometry of QSO 0957+561; application to time delay and microlensing
• SBS 0909+532: A New Double Gravitational Lens or Binary Quasar?
• Image reconstruction technique and optical monitoring of the QSO2237+0305 from Maidanak Observatory in 2002 -- 2003
• Multiple delays in QSO 0957+561: observational evidence and interpretation
• COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses IV. Models of prospective time-delay lenses
• The dark halo of the main lens galaxy in QSO 0957+561
• GLITP Optical Monitoring of QSO 0957+561: VR Light Curves and Variability

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