English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present new light curves for the four bright images of the five imagecluster-lensed quasar gravitational lens system SDSS~J1004+4112. The lightcurves span 14.5 yr and allow measurement of the time delay between thetrailing bright quasar image D and the leading image C. When we fit all fourlight curves simultaneously and combine the models using the Bayes informationcriterion, we find a time delay of $\Delta t_{DC}= 2458.47 \pm 1.02$ days (6.73yr), the longest ever measured for a gravitational lens. For the other twoindependent time delays we obtain $\Delta t_{BC}=782.20 \pm 0.43$ days (2.14yr) and $\Delta t_{AC}= 825.23 \pm 0.46$ days (2.26 yr), in agreement withprevious results. The information criterion is needed to weight the results forlight curve models with different polynomial orders for the intrinsicvariability and the effects of differential microlensing. The results using theAkaike information criterion are slightly different, but, in practice, theabsolute delay errors are all dominated by the $\sim 4\%$ cosmic variance inthe delays rather than the statistical or systematic measurement uncertainties.Despite the lens being a cluster, the quasar images show slow differentialvariability due to microlensing at the level of a few tenths of a magnitude.

The Longest Delay: a 14.5 Yr Campaign to Determine the Third Time Delay in the Lensing Cluster SDSS~J1004+4112