Hubble Frontier Field

• The HFF program (Koekemoer et al. 2016; Lotz et al. 2017) consists of multi-cycle HST observations to target six galaxy lensing clusters in parallel with six parallel blank field images (6 arcmins from the cluster core).

HST employed 840 orbits (140 orbits for each galaxy cluster) to observe the HFF galaxy clusters, achieving a superb depth of � 28.7~29 magnitudes (5 sigma).

Taking into account the gravitational lensing effects, the effective depths of the HFF observations are 30~33 magnitudes over very small volumes.

For all the HFF targets, HST obtained images with the ACS and WFC3, in a total of seven broad-band �filters (F435W, F606W, F814W, F105W, F125W, F140W, F160W).