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Description
We present six new time-delay measurements obtained from Rc-band monitoring data acquired at the MPIA 2.2m telescope at La Silla observatory between October 2016 and February 2020. The lensed quasars HE 0047-1756, WG 0214-2105, DES 0407-5006, 2M 1134-2103, PSJ 1606-2333 and DES 2325-5229 were observed almost daily at high signal-to-noise ratio to obtain high-quality light curves where we can record fast and small-amplitude variations of the quasars. We measure time delays between all pairs of multiple images with only one or two seasons of monitoring at the exception of the time delays relative to image D of PSJ 1606-2333. The most precise estimate is obtained for the delay between image A and image B of DES 0407-5006, with {tau}_AB_=-128.4^+3.5^_-3.8_ days (2.8% precision) including systematics due to extrinsic variability in the light curves. For HE 0047-1756, we combine our high-cadence data with measurements from decade-long light-curves from previous COSMOGRAIL campaigns, and reach a precision of 0.9 day on the final measurement. The present work demonstrates the feasibility of measuring time delays in lensed quasars in only one or two seasons, provided high signal-to-noise ratio data are obtained at a cadence close to daily.
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