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  • Adaptive PSF fitting – a hi...
    Akhunov, T A; Wertz, O; Elyiv, A; Gaisin, R; Artamonov, B P; Dudinov, V N; Nuritdinov, S N; Delvaux, C; Sergeyev, A V; Gusev, A S; Bruevich, V V; Burkhonov, O; Zheleznyak, A P; Ezhkova, O; Surdej, J

    Monthly Notices of the Royal Astronomical Society, 03/2017, Letnik: 465, Številka: 3
    Journal Article, Web Resource

    We present new photometric observations of H1413+117 acquired during seasons between 2001 and 2008 in order to estimate the time delays between the lensed quasar images and to characterize at best the on-going micro-lensing events. We propose a highly performing photometric method called the adaptive point spread function fitting and have successfully tested this method on a large number of simulated frames. This has enabled us to estimate the photometric error bars affecting our observational results. We analysed the V- and R-band light curves and V-R colour variations of the A-D components which show short- and long-term brightness variations correlated with colour variations. Using the ... and dispersion methods, we estimated the time delays on the basis of the R-band light curves over the seasons between 2003 and 2006. We have derived the new values: ...tAB = -17.4 plus or minus 2.1, ...tAC = -18.9 plus or minus 2.8 and ...tAD = 28.8 plus or minus 0.7 d using the ... method (B and C are leading, D is trailing) with 1s confidence intervals. We also used available observational constraints (resp. the lensed image positions, the flux ratios in mid-IR and two sets of time delays derived in the present work) to update the lens redshift estimation. We obtained zl=1.95... which is in good agreement with previous estimations. We propose to characterize two kinds of micro-lensing events: micro-lensing for the A, B, C components corresponds to typical variations of ~10-4 mag d-1 during all the seasons, while the D component shows an unusually strong micro-lensing effect with variations of up to ~10-3 mag d-1 during 2004 and 2005. (ProQuest: ... denotes formulae/symbols omitted.)