Probing Supermassive Black Hole Binaries with Orbital Resonances of Laser-Ranged Satellite

Abstract

The µHz gravitational waves (GWs) from coalescing supermassive black hole binaries (SMBHBs) carry extensive information which is valuable for the research of cosmology, astronomy, and fundamental physics. Before the operations of space-borne antennas like LISA and Taiji, current detectors are insensitive to GWs in this frequency range, leaving a gap to be filled with other methods. While, such GWs can induce lasting imprints on satellite orbit motions through resonant effect, and observational evidence for this phenomenon may be obtained via the satellite laser ranging (SLR) measurements. Our study is mainly dedicated to exploring the potential of SLR as a probe of GWs from SMBHBs. Based on previous work, we calculated the resonant evolutions of satellite orbits both numerically and analytically, and investigated the dependence on relevant parameters. Results of the signal-to-noise ratio (SNR) analysis showed that the imprint of an individual signal may not be quite remarkable, whereas before the operation of space-borne antennas, the possibility of discovering the first GW from a coalescing SMBHB with SLR missions is still promising. The thorough re-analysis of the documented data of SLR missions are also suggested.