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  1. Abstract

    We report the detection of the CO(12–11) line emission toward G09-83808 (or H-ATLAS J090045.4+004125), a strongly-lensed submillimeter galaxy at z = 6.02, with Atacama Large Millimeter/submillimeter Array observations. Combining previously detected [O iii] 88 μm, [N ii] 205 μm, and dust continuum at 0.6 mm and 1.5 mm, we investigate the physical properties of the multi-phase interstellar medium in G09-83808. A source-plane reconstruction reveals that the region of the CO(12–11) emission is compact ($R_\mathrm{{e, CO}}=0.49^{+0.29}_{-0.19}\:\mbox{kpc}$) and roughly coincides with that of the dust continuum. Non-local thermodynamic equilibrium radiative transfer modeling of CO spectral-line energy distribution reveals that most of the CO(12–11) emission comes from a warm (kinetic temperature of Tkin = 320 ± 170 K) and dense [log (nH2/cm−3) = 5.4 ± 0.6] gas, indicating that the warm and dense molecular gas is concentrated in the central 0.5 kpc region. The luminosity ratio in G09-83808 is estimated to be LCO(12-11)/LCO(6-5) = 1.1 ± 0.2. The high ratio is consistent with those in local active galactic nuclei (AGNs) and 6 < z < 7 quasars, the fact of which implies that G09-83808 would be a good target to explore dust-obscured AGNs in the epoch of reionization. In the reconstructed [O iii] 88 μm and [N ii] 205 μm cubes, we also find that a monotonic velocity gradientmore »is extending over the central starburst region by a factor of 2 and that star-forming sub-components exist. High-resolution observations of bright [C ii] 158 μm line emissions will enable us to characterize the kinematics of a possible rotating disk and the nature of the sub-components.

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  2. Abstract

    Active galactic nucleus (AGN) feedback is postulated as a key mechanism for regulating star formation within galaxies. Studying the physical properties of the outflowing gas from AGNs is thus crucial for understanding the coevolution of galaxies and supermassive black holes. Here we report 55 pc resolution ALMA neutral atomic carbon [Ci]3P13P0observations toward the central 1 kpc of the nearby Type 2 Seyfert galaxy NGC 1068, supplemented by 55 pc resolution CO(J= 1−0) observations. We find that [Ci] emission within the central kiloparsec is strongly enhanced by a factor of >5 compared to the typical [Ci]/CO intensity ratio of ∼0.2 for nearby starburst galaxies (in units of brightness temperature). The most [Ci]-enhanced gas (ratio > 1) exhibits a kiloparsec-scale elongated structure centered at the AGN that matches the known biconical ionized gas outflow entraining molecular gas in the disk. A truncated, decelerating bicone model explains well the kinematics of the elongated structure, indicating that the [Ci] enhancement is predominantly driven by the interaction between the ISM in the disk and the highly inclined ionized gas outflow (which is likely driven by the radio jet). Our results strongly favor the “CO dissociation scenario” rather than the “in situ C formation” one,more »which prefers a perfect bicone geometry. We suggest that the high-[Ci]/CO intensity ratio gas in NGC 1068 directly traces ISM in the disk that is currently dissociated and entrained by the jet and the outflow, i.e., the “negative” effect of the AGN feedback.

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