ZTF DR7 r survey collection

ZTF uses a 47 square degree field with a 600 megapixel camera to scan the entire northern visible sky at rates of ~ 3760 square degrees/hour to median depths of g ~ 20.8 and r ~ 20.6 mag (AB, 5sigma in 30 sec). The Seventh ZTF Public Data Release (DR7) builds upon the Sixth Data Release (DR6) to include products from (i) an additional two months of data acquired under the Public Survey (+ February 2021 to June 2021) and (ii) data acquired under Private Survey time (from both partnership and Caltech programs) from approximately the first 23.4 months of science operations (~ March 2018 to February 2020).

The latter is included due to the 18 month proprietary period up to this release date.Original acknowledgement for data: Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, and IN2P3, France.