Event rate for extreme mass ratio burst signals in the Laser Interferometer Space Antenna band

Stellar mass compact objects in short-period (P less than or similar to 10(3) s) orbits about a 10(4.5)-10(7.5) M-circle dot massive black hole (MBH) are thought to be a significant continuous-wave source of gravitational radiation for the ESA/NASA Laser Interferometer Space Antenna (LISA) gravitational wave detector. These extreme mass ratio inspiral sources began in long-period, nearly parabolic orbits that have multiple close encounters with the MBH. The gravitational radiation emitted during the close encounters may be detectable by LISA as a gravitational wave burst if the characteristic passage timescale is less than 10(5) s. Scaling a static, spherical model to the size and mass of the Milky Way bulge, we estimate an event rate of similar to 15 yr(-1) for such burst signals, detectable by LISA with signal-to-noise ratio greater than 5, originating in our Galaxy. When extended to include Virgo Cluster galaxies, our estimate increases to a gravitational wave burst rate of similar to 18 yr(-1). We conclude that these extreme mass ratio burst sources may be a steady and significant source of gravitational radiation in the LISA data streams.