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Abstract We report the detection of an ionized gas outflow from an X-ray active galactic nucleus hosted in a massive quiescent galaxy in a protocluster at z = 3.09 (J221737.29+001823.4). It is a type-2 QSO with broad ( W 80 > 1000 km s −1 ) and strong ( log ( L [ OIII ] /erg s −1 ) ≈ 43.4) [O iii ] λ λ 4959,5007 emission lines detected by slit spectroscopy in three-position angles using Multi-Object Infra-Red Camera and Spectrograph (MOIRCS) on the Subaru telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck-I telescope. In the all slit directions, [O iii ] emission is extended to ∼15 physical kpc and indicates a powerful outflow spreading over the host galaxy. The inferred ionized gas mass outflow rate is 22 ± 3 M ⊙ yr −1 . Although it is a radio source, according to the line diagnostics using H β , [O ii ], and [O iii ], photoionization by the central QSO is likely the dominant ionization mechanism rather than shocks caused by radio jets. On the other hand, the spectral energy distribution of the host galaxy is well characterized as a quiescent galaxy that has shut down star formation several hundred Myr ago. Our results suggest a scenario that QSOs are powered after the shutdown of the star formation and help complete the quenching of massive quiescent galaxies at high redshift. 

Abstract We present Atacama Large Millimeter/submillimeter Array (ALMA) imaging of molecular gas across the full star-forming disk of the barred spiral galaxy M83 in CO( J = 1–0). We jointly deconvolve the data from ALMA’s 12 m, 7 m, and Total Power arrays using the MIRIAD package. The data have a mass sensitivity and resolution of 10 4 M ⊙ (3 σ ) and 40 pc—sufficient to detect and resolve a typical molecular cloud in the Milky Way with a mass and diameter of 4 × 10 5 M ⊙ and 40 pc, respectively. The full disk coverage shows that the characteristics of molecular gas change radially from the center to outer disk, with the locally measured brightness temperature, velocity dispersion, and integrated intensity (surface density) decreasing outward. The molecular gas distribution shows coherent large-scale structures in the inner part, including the central concentration, offset ridges along the bar, and prominent molecular spiral arms. However, while the arms are still present in the outer disk, they appear less spatially coherent, and even flocculent. Massive filamentary gas concentrations are abundant even in the interarm regions. Building up these structures in the interarm regions would require a very long time (≳100 Myr). Instead, they must have formed within stellar spiral arms and been released into the interarm regions. For such structures to survive through the dynamical processes, the lifetimes of these structures and their constituent molecules and molecular clouds must be long (≳100 Myr). These interarm structures host little or no star formation traced by H α . The new map also shows extended CO emission, which likely represents an ensemble of unresolved molecular clouds. 

Abstract We report a massive quiescent galaxy at z spec = 3.0922 − 0.004 + 0.008 spectroscopically confirmed at a protocluster in the SSA22 field by detecting the Balmer and Ca ii absorption features with the multi-object spectrometer for infrared exploration on the Keck I telescope. This is the most distant quiescent galaxy confirmed in a protocluster to date. We fit the optical to mid-infrared photometry and spectrum simultaneously with spectral energy distribution (SED) models of parametric and nonparametric star formation histories (SFHs). Both models fit the observed SED well and confirm that this object is a massive quiescent galaxy with a stellar mass of log ( M ⋆ / M ⊙ ) = 11.26 − 0.04 + 0.03 and 11.54 − 0.00 + 0.03 , and a star formation rate of SFR/ M ⊙ yr −1 < 0.3 and = 0.01 − 0.01 + 0.03 for parametric and nonparametric models, respectively. The SFH from the former modeling is described as an instantaneous starburst whereas that of the latter modeling is longer-lived, but both models agree with a sudden quenching of the star formation at ∼0.6 Gyr ago. This massive quiescent galaxy is confirmed in an extremely dense group of galaxies predicted as a progenitor of a brightest cluster galaxy formed via multiple mergers in cosmological numerical simulations. We discover three new plausible [O iii ] λ 5007 emitters at 3.0791 ≤ z spec ≤ 3.0833 serendipitously detected around the target. Two of them just between the target and its nearest massive galaxy are possible evidence of their interactions. They suggest the future great size and stellar mass evolution of this massive quiescent galaxy via mergers.