High-resolution submillimeter imaging of the Lyα blob 1 in SSA 22

We present ∼2″ resolution submillimeter observations of the submillimeter luminous giant Lyα blob (LAB1) in the SSA 22 protocluster at redshift z = 3.1 with the Submillimeter Array (SMA). Although the expected submillimeter flux density is 16 mJy at 880 μm, no emission is detected with the 2.4″ × 1.9″ (18 × 14 kpc) beam at the 3 σ level of 4.2 mJy beam^-1 in the SMA field of view of 35″. This is in contrast to the previous lower angular resolution (15″) observations where a bright (17 mJy) unresolved submillimeter source was detected at 850 μm toward the LAB1 using the Submillimeter Common-User Bolometer Array on the James Clerk Maxwell Telescope. The SMA nondetection suggests that the spatial extent of the submillimeter emission of LAB1 should be larger than 4″ (>30 kpc). The most likely interpretation of the spatially extended submillimeter emission is that starbursts occur throughout the large area in LAB1. Some part of the submillimeter emission may come from spatially extended dust expelled from starburst regions by galactic superwind. The spatial extent of the submillimeter emission of LAB1 is similar to those of high-redshift radio galaxies rather than submillimeter galaxies.