GLITP Optical Monitoring of QSO 0957+561: VR Light Curves and Variability

Abstract

The GLITP collaboration observed the first gravitational lens system (QSO 0957+561) from 2000 February 3 to 2000 March 31. The daily VR observations were made with the 2.56-m Nordic Optical Telescope at Roque de los Muchachos Observatory, La Palma (Spain). We have derived detailed and robust VR light curves of the two components Q0957+561A and Q0957+561B. In spite of the excellent sampling rate, we have not found evidence in favor of true daily variability. With respect to variability on time-scales of several weeks, we measure VR gradients of about -0.8 mmag/day in Q0957+561A and + 0.3 mmag/day in Q0957+561B. The gradients are very probably originated in the far source, thus adopting this reasonable hypothesis (intrinsic variability), we compare them to the expected gradients during the evolution of a compact supernova remnant at the redshift of the source quasar. The starburst scenario is roughly consistent with some former events, but the new gradients do not seem to be caused by supernova remnant activity.

arXiv commentMNRAS, in press (21 pages, 11 figures)

References in corpus (20)

• A Robust Determination of the Time Delay in 0957+561A,B and a Measurement of the Global Value of Hubble's Constant
• Optical Variability in Active Galactic Nuclei: Starbursts or Disk Instabilities?
• Variability in active galactic nuclei: confrontation of models with observations
• SN 1988Z: Spectro-photometric catalogue and energy estimates
• QSO variability: probing the Starburst model
• QSO 2237+0305 VR light curves from Gravitational Lenses International Time Project optical monitoring
• The gravitational lens MG0414+0534: a link between red galaxies and dust
• A Rapid Microlensing Event in the Q0957+561 A,B Gravitational Lens System
• A Sharp Event in the Image a Light Curve of the Double Quasar 0957+561 and Prediction of the 1996 Image B Light Curve
• Improved Parameters and New Lensed Features for Q0957+561 from WFPC2 Imaging
• BVRI photometry of QSO 0957+561A, B: Observations, new reduction method and time delay
• Time delay in QSO 0957+561 from 1984-99 optical data
• New aperture photometry of QSO 0957+561; application to time delay and microlensing
• Source Size Limitation from Variabilities of a Lensed Quasar
• Multiple delays in QSO 0957+561: observational evidence and interpretation
• Short-timescale Fluctuations in the Difference Light Curves of QSO 0957+561A,B: Microlensing or Noise?
• A Large Brightness Enhancement of the QSO 0957+561 A Component
• Ultraviolet structure in the lensed QSOs 0957+561
• Precision Photometry for Q0957+561 Images A and B
• Five nights of intensive R- and V-band photometry of QSO 0957+561A,B

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• New two-colour light curves of Q0957+561: time delays and the origin of intrinsic variations
• Time delay of SBS 0909+532
• Quasar Microlensing: when compact masses mimic smooth matter
• The dark halo of the main lens galaxy in QSO 0957+561
• New VR magnification ratios of QSO 0957+561
• TDCOSMO XVII. New time delays in 22 lensed quasars from optical monitoring with the ESO-VST 2.6m and MPG 2.2m telescopes
• Structure function of the UV variability of Q0957+561