DETECTION OF ATOMIC CARBON [C II] 158 μm AND DUST EMISSION FROM A z=7.1 QUASAR HOST GALAXY

Using the IRAM Plateau de Bure Interferometer, we report the detection of the 158 mu m [C II] emission line and underlying dust continuum in the host galaxy of the quasar ULAS J112001.48+064124.3 (hereafter J1120+0641) at z = 7.0842 +/- 0.0004. This is the highest redshift detection of the [C II] line to date, and allows us to put the first constraints on the physical properties of the host galaxy of J1120+0641. The [C II] line luminosity is 1.2 +/- 0.2x10(9) L-circle dot, which is a factor similar to 4 lower than observed in a luminous quasar at z = 6.42 (SDSS J1148+5251). The underlying far-infrared (FIR) continuum has a flux density of 0.61 +/- 0.16 mJy, similar to the average flux density of z similar to 6 quasars that were not individually detected in the rest-frame FIR. Assuming that the FIR luminosity of L-FIR = 5.8 x 10(11)-1.8 x 10(12) L-circle dot is mainly powered by star formation, we derive a star formation rate in the range 160-440 M-circle dot yr(-1) and a total dust mass in the host galaxy of 6.7 x 10(7)-5.7 x 10(8) M-circle dot (both numbers have significant uncertainties given the unknown nature of dust at these redshifts). The [C II] line width of sigma(V) = 100 +/- 15 km s(-1) is among the smallest observed when compared to the molecular line widths detected in z similar to 6 quasars. Both the [C II] and dust continuum emission are spatially unresolved at the current angular resolution of 2.0 x 1.7 arcsec(2) (corresponding to 10 x 9 kpc(2) at the redshift of J1120+0641).