A Brief Overview of the Palomar Transient Factory (PTF) and Recent Progress of PTF-RRL Program at the National Central University

Chow-Choong Ngeow

The Palomar Transient Factory (PTF) and its successor, the intermediate-PTF (iPTF), are wide-field synoptic surveying projects aimed to explore the transient universe. The time-series data from PTF/iPTF can also be used for asteroids and variable star research. The PTF/iPTF projects utilized the 48-inch Samuel Oschin Telescope located at the Palomar Observatory to carry out the surveys, which was equipped with the CFH12K CCD. This mosaic CCD has a pixel scale of 1.01'' per pixel, resulting in a field-of-view of ∼ 7.2 degree squared. With an exposure time of 60 seconds, the PTF/iPTF can reach to a depth of R ∼ 20 mag, suitable to search for RR Lyrae stars (RRLs) located in the Galactic halo. At the Graduate Institution of Astronomy of the National Central University (IANCU), we are interested in using RRLs found in PTF/iPTF data for various scientific investigations, including the Galactic halo sub-structures. In this presentation, we report the recent progress of our PTF-RRL program, including the derivation of metallicity-light curve relation in the native PTF/iPTF R-band filter. Our relation can be immediately applied to distant RRLs and estimate their metallicity based on the PTF/iPTF light curves.

Proceedings of the Polish Astronomical Society, vol. 6, 308-309 (2018)

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