The rate of fast radio bursts ( FRBs ) in the direction of nearby galaxy clusters is expected to be higher than the mean cosmological rate if intrinsically faint FRBs are numerous .
In this paper , we describe a targeted search for faint FRBs near the core of the Virgo cluster using the Australian Square Kilometer Array Pathfinder telescope .
During 300 hr of observations , we discovered one burst , FRB 180417 , with dispersion measure DM = 474.8 cm ^ { -3 } pc .
The FRB was promptly followed up by several radio telescopes for 27 h , but no repeat bursts were detected .
An optical follow-up of FRB 180417 using the PROMPT5 telescope revealed no new sources down to an R -band magnitude of 20.1 .
We argue that FRB 180417 is likely behind the Virgo cluster as the Galactic and intracluster DM contribution are small compared to the DM of the FRB , and there are no galaxies in the line of sight .
The non-detection of FRBs from Virgo constrains the faint-end slope , \alpha < 1.52 ( at 68 % confidence limit ) , and the minimum luminosity , L _ { min } \gtrsim 2 \times 10 ^ { 40 } erg s ^ { -1 } ( at 68 % confidence limit ) , of the FRB luminosity function assuming cosmic FRB rate of 10 ^ { 4 } FRBs sky ^ { -1 } day ^ { -1 } with flux above 1 Jy located out to redshift of 1 .
Further FRB surveys of galaxy clusters with high-sensitivity instruments will tighten the constraints on the faint end of the luminosity function and , thus , are strongly encouraged .