CO (7-6), [C I] 370 μm, and [N II] 205 μm Line Emission of the QSO BRI1335-0417 at Redshift 4.407

Journal article

We present the results from our Atacama Large Millimeter/submillimeter Array (ALMA) imaging observations of the CO(7-6), [C i] 370 μm (hereafter [C i]), and [N ii] 205 μm (hereafter [N ii]) lines and their underlying continuum emission of BRI 1335-0417, an infrared bright quasar at z = 4.407. At the achieved resolutions of ∼1.″1 to 1.″2 (or 7.5-8.2 kpc), the continuum at 205 and 372 μm (rest frame), the CO(7-6), and the [C i] emissions are at best barely resolved whereas the [N ii] emission is well resolved with a beam-deconvolved major axis of 1.″3(±0.″3) or 9(±2) kpc. As a warm dense gas tracer, the CO(7-6) emission shows a more compact spatial distribution and a significantly higher peak velocity dispersion than the other two lines that probe lower density gas, a picture favoring a merger-Triggered star formation (SF) scenario over an orderly rotating SF disk. The CO(7-6) data also indicate a possible QSO-driven gas outflow that reaches a maximum line-of-sight velocity of 500-600 km s-1. The far-infrared (FIR) dust temperature (Tdust) of 41.5 K from a graybody fit to the continuum agrees well with the average Tdustinferred from various line luminosity ratios. The resulting LCO(7-6)/LFIRluminosity ratio is consistent with that of local luminous infrared galaxies powered predominantly by SF. The LCO(7-6)-inferred SF rate is 5.1(±1.5) × 103Moyr-1. The system has an effective star-forming region of kpc in diameter and a molecular gas reservoir of ∼5 × 1011Mo.

Authors: Lu, N; Cao, T; Diaz-Santos, T; Zhao, Y; Privon, G

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Institute of Physics
• Journal: Astrophysical Journal
• Volume: 864
• Issue: 1
• Pages: 38
• Publication date: 2018-08-29
• Acceptance date: 2018-07-13
• DOI: 10.3847/1538-4357/aad3c9
• EISSN: 1538-4357
• ISSN: 0004-637X
• Keywords: submillimeter: galaxies; galaxies: ISM; infrared: galaxies; ISM: molecules; galaxies: active; galaxies: star formation