Angular clustering and host halo properties of [OII] emitters at $z >1$ in the Subaru HSC survey

Abstract

We study the angular correlation function of star-forming galaxies and properties of their host dark matter halos at z > 1 using the Subaru Hyper-Suprime Cam (HSC) survey. We use [OII] emitters identified using two narrow-band (NB) filters, NB816 and NB921, in the Deep/UltraDeep layers, which respectively cover large angular areas of 16.3 deg 2 and 16.9 deg 2 . Our sample contains 8302 and 9578 [OII] emitters at z = 1.19 (NB816) and z = 1.47 (NB921), respectively. We detect a strong clustering signal over a wide angular range, 0.001 < θ < 1 [deg], with the bias b = 1.61 +0.13 −0.11 (z = 1.19) and b = 2.09 +0.17 −0.15 (z = 1.47). We also find the clear deviation of the correlation from a simple power-law form. To interpret the measured clustering signal, we adopt a halo occupation distribution (HOD) model which is constructed to explain the spatial distribution of galaxies selected by a star formation rate. The observed correlation function and number density are simultaneously explained by the best-fitting HOD model. From the constrained HOD model, the average mass of halos hosting the [OII] emitters is derived to be log M eff /(h −1 M ) = 12.70 +0.09 −0.07 and 12.61 +0.09 −0.05 at z = 1.19 and 1.47, respectively, which will become halos with the present-day mass, M ∼ 1.5 × 10 13 h −1 M . The satellite fraction of the [OII] emitter sample is found to be f sat ∼ 0.15. All these values are consistent with the previous studies of similar samples, but we obtain tighter constraints due to the high number density and large angular coverage of our sample. The results obtained for host halos of [OII] emitters in this paper are expected to be applicable to upcoming emission line galaxy surveys such as the Subaru Prime Focus Spectrograph survey.