2010ApJ...714L.162H

We report the detection of 158 µm [C II] fine-structure line emission from MIPS J142824.0+352619, a hyperluminous (L_IR∼ 10¹³ L_☉) starburst galaxy at z = 1.3. The line is bright, corresponding to a fraction L_[C II]_/LFIR_≈ 2x10^–3 of the far-IR (FIR) continuum. The [C II], CO, and FIR continuum emission may be modeled as arising from photodissociation regions (PDRs) that have a characteristic gas density of n ∼ 10^4.2/cm3, and that are illuminated by a far-UV radiation field ∼10^3.2 times more intense than the local interstellar radiation field. The mass in these PDRs accounts for approximately half of the molecular gas mass in this galaxy. The L_[C II]_/LFIR_ ratio is higher than observed in local ultraluminous infrared galaxies or in the few high-redshift QSOs detected in [C II], but the L_[C II]_/LFIR_ and L_CO/L_FIRratios are similar to the values seen in nearby starburst galaxies. This suggests that MIPS J142824.0+352619 is a scaled-up version of a starburst nucleus, with the burst extended over several kiloparsecs.