Detection of astrophysical gravitational wave sources by TianQin and LISA

TianQin and LISA are space-based laser interferometer gravitational wave (GW) detectors planned to be launched in the mid-2030s. Both detectors will detect low-frequency GWs around $10^{-2}\,{\rm Hz}$, however, TianQin is more sensitive to frequencies above this common sweet-spot while LISA is more sensitive to frequencies below $10^{-2}\,{\rm Hz}$. Therefore, TianQin and LISA will be able to detect the same sources but with different accuracy for different sources and their parameters. We study the detection distance and the detection accuracy with which TianQin and LISA will be able to detect some of the most important astrophysical sources -- massive black hole binaries, stellar-mass black holes binaries, double white dwarfs, extreme mass ratio inspirals, light and heavy intermediate mass ratio inspirals, as well as the stochastic gravitational background produced by binaries. We, further, study the detection distance and detection accuracy from joint detection. We compare the results obtained by the three detection scenarios highlighting the gains from joint detection as well as the contribution of TianQin and LISA to a combined study of astrophysical sources. In particular, we consider the different orientations, lifetimes, and duty cycles of the two detectors to explore how they can give a more complete picture when working together.