First Systematic Search for Oxygen-line Blobs at High Redshift: Uncovering AGN Feedback and Star Formation Quenching

摘要: We present the first systematic search for extended metal-line [O II] λλ3726, 3729 nebulae, or blobs (O IIBs), at z = 1.2 using deep narrowband imaging with a survey volume of 1.9 × 105 Mpc3 on 0.62 deg2 sky Subaru-XMM Deep Survey (SXDS) field. discover giant O IIB, called "O IIB 1," spatial extent over ~75 kpc spectroscopic redshift 1.18, and also identify total 12 IIBs size >30 kpc. Our optical spectrum 1 presents [Ne V] λ3426 line 6σ level, indicating that this object harbors an obscured type-2 active galactic nucleus (AGN). The presence gas outflows in is suggested by two marginal detections Fe II λ2587 absorption II* λ2613 emission lines both which are blueshifted as large 500-600 km s–1, heating source AGN associated shock excitation rather than supernovae produced starbursts. number density 1-type estimated to be ~5 10–6 Mpc–3 ~ 1.2, comparable AGNs driving outflow similar redshift, suggesting only activity. On other hand, small IIBs, 6 10–5 Mpc–3, compared galaxies blue cloud same MB range, may imply 3% star-forming quenching star formation through involving emission.