Study of the detection capability and observation strategy of WFST-like telescope for kilonovae

We simulated the sources of binary neutron star mergers at redshift z < 0.2 and calculated the light curves for the kilonovae associated with these mergers by adopting a simple kilonova model. We investigated the detectability of these simulated kilonovae using the wide field survey telescope (WFST), large synoptic survey telescope (LSST), and Chinese space station telescope (CSST). We determined that the best band for WFST and LSST is the g band, which could detect most sources. Moreover, the best two-band-observing strategies are observing events through the g/r band in the first 1.5 d and observing events via the r/i band after 1.5 d. For CSST, by observing via a deep slitless spectrum, we determined that GU band could detect the events in the first 1.5 d, the GV band could detect the events in the first 3.5 d, and the GI band could detect the events in the longest time. Meanwhile, we determined that the effect of viewing angle on light curve is related to mass ratio. For sources with a mass ratio q < 0.8, the effect of viewing angle on the lightcurve is small. Conversely, for sources with a mass ratio q > 0.8, the effect of viewing angle on the light curve is significant.