The FMOS-COSMOS Survey of Star-forming Galaxies at Z ∼ 1.6. V: Properties of Dark Matter Halos Containing Ha Emitting Galaxies

We study the properties of dark matter halos that contain star-forming galaxies at 1.43 <= z <= 1.74, using the FMOS-COSMOS survey. The sample consists of 516 objects with a detection of the Ha emission line, which represent the star forming population at this epoch, having a stellar mass range of 10(9.57) <= M*/M circle dot less than or similar to 10(11.4) and a star-formation rate range of 15 less than or similar to SFR/(Me-circle dot yr(-1)) less than or similar to 600. We measure the projected two-point correlation function while carefully taking into account observational biases, and find a significant clustering amplitude at scales of 0.04-10 h(-1) cMpc, with a correlation length r(0) = 5.26(-0.62)(+0.75) h(-1) cMpc and a bias b = 2.44(-0.32)(+0.38) We interpret our clustering measurement using a halo occupation distribution model. The sample galaxies appear to reside in halos with mass M-h = 4.71 (+1.19)(-1.62) x 10(12) h(-1) M-circle dot on average, which will likely become present-day halos of mass M-h (z =0) similar to 2 x 10(13) h(-1) M-circle dot, equivalent to the typical halo mass scale of galaxy groups. We then confirm the decline of the stellar-to-halo mass ratio at M-h < 10(12) M-circle dot, finding M-*/M-h approximate to 5 x 10(-3) at M-h = 7.5 x 10(11) M-circle dot, which is lower by a factor of 2-4 than those measured at higher masses (M-h similar to 10(12-13) Me-circle dot). Finally, we use our results to illustrate the future capabilities of Subaru's Prime-Focus Spectrograph, a next-generation instrument that will provide strong constraints on the galaxy-formation scenario by obtaining precise measurements of galaxy clustering at z > 1.