The FMOS-COSMOS survey of star-forming galaxies at $z\sim 1.6$. V: Properties of dark matter halos containing H$\alpha$ emitting galaxies

We study the properties of dark matter halos that contain star-forming galaxies at $1.43\le z\le 1.74$ using the FMOS-COSMOS survey. The sample consists of 516 objects with a detection of the H$\alpha$ emission line, that represent the star-forming population at this epoch having a stellar mass range of ${10}^{9.57}\le M_{\ast }\mathrm{/}{M}_{\odot }\lesssim {10}^{11.4}$ and a star formation rate range of $15\lesssim \mathrm{S}\mathrm{F}\mathrm{R}\mathrm{/}(M_{\odot }\mathrm{y}{\mathrm{r}}^{-1})\lesssim 600$. We measure the projected two-point correlation function while carefully taking into account observational biases, and find a significant clustering amplitude at scales of $0.04$-$10h^{-1}\mathrm{c}\mathrm{M}\mathrm{p}\mathrm{c}$, with a correlation length $r_0 = 5.21^{+0.70}{-0.67}~h^{-1}~$\mathrm{c}\mathrm{M}\mathrm{p}\mathrm{c}$$andabias$b=2.59^{+0.41}{-0.34}$. We interpret our clustering measurement using a halo occupation distribution model. The sample galaxies appear to reside in halos with mass $M_$\mathrm{h}$ = 4.6^{+1.1}{-1.6}\times10^{12}~h^{-1}M\odot$ on average that will likely become present-day halos of mass $M_$\mathrm{h}$ (z=0) \sim2\times10^{13}~h^{-1}M_\odot$, equivalent to the typical halo mass scale of galaxy groups. We then confirm the decline of the stellar-to-halo mass ratio at $M_{\mathrm{h}}<{10}^{12}{M}_{\odot }$, finding $M_\ast/M_$\mathrm{h}$ \approx 5\times10^{-3}$at$M_$\mathrm{h}$=10^{11.86}~M_\odot$, which is lower by a factor of 2-4 than those measured at higher masses. 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 $z>1$.