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 [C
- NSF-PAR ID:
- 10342064
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 923
- Issue:
- 1
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 83
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract i ]3P 1−3P 0observations 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, 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. -
null (Ed.)ABSTRACT Haro 2, a nearby dwarf starburst dwarf galaxy with strong Ly α emission, hosts a starburst that has created outflows and filaments. The clear evidence for galactic outflow makes it an ideal candidate for studying the role of molecular gas in feedback processes in a dwarf galaxy. We observed CO(2–1) in Haro 2 at the Submillimeter Array in the compact and extended configurations, and have mapped the molecular emission with velocity resolution 4.1 km s−1 and spatial resolution 2.0 × 1.6 arcsec2. With this significant increase of resolution over previous measurements, we see that the molecular gas comprises two components: bright clumps associated with the embedded star clusters of the starburst, and fainter extended emission east of the starburst region. The extended emission coincides with an X-ray bubble and has the kinematic signatures of an outflowing cone or of an expanding shell or bubble; the velocity range is ∼35 km s−1. We suggest that the starburst winds that created the X-ray bubble have entrained the molecular gas, and that the apparent velocity gradient at an angle to the photometric axis is an artefact caused by the outflow. The molecular and X-ray activity is on the east of the galaxy and the ionized outflow and optical filaments are west; their relationship is not clear.more » « less
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Context. The interaction between active galactic nuclei (AGNs) and their host galaxies is scarcely resolved. Narrow-line Seyfert 1 (NLS1) galaxies are believed to represent AGN at early stages of their evolution and to allow one to observe feeding and feedback processes at high black hole accretion rates. Aims. We aim to constrain the properties of the ionised gas outflow in Mrk 1044, a nearby super-Eddington accreting NLS1. Based on the outflow energetics and the associated timescales, we estimate the outflow’s future impact on the ongoing host galaxy star formation on different spatial scales. Methods. We applied a spectroastrometric analysis to observations of Mrk 1044’s nucleus obtained with the adaptive-optics-assisted narrow field mode of the VLT/MUSE instrument. This allowed us to map two ionised gas outflows traced by [O III ], which have velocities of −560 ± 20 km s −1 and −144 ± 5 km s −1 . Furthermore, we used an archival spectrum from the Space Telescope Imaging Spectrograph on HST to identify two Ly- α absorbing components that escape from the centre with approximately twice the velocity of the ionised gas components. Results. Both [O III ] outflows are spatially unresolved and located close to the AGN (< 1 pc). They have gas densities higher than 10 5 cm −3 , which implies that the BPT diagnostic cannot be used to constrain the underlying ionisation mechanism. We explore whether an expanding shell model can describe the velocity structure of Mrk 1044’s multi-phase outflow. In the ionised gas emission, an additional outflowing component, which is spatially resolved, is present. It has a velocity of −211 ± 22 km s −1 and a projected size of 4.6 ± 0.6 pc. Our kinematic analysis suggests that significant turbulence is present in the interstellar medium around the nucleus, which may lead to a condensation rain, potentially explaining the efficient feeding of Mrk 1044’s AGN. Within the innermost 0.5″ (160 pc), we detect modest star formation hidden by the beam-smeared emission from the outflow. Conclusions. We estimate that the multi-phase outflow was launched < 10 4 yr ago. Together with the star formation in the vicinity of the nucleus, this suggests that Mrk 1044’s AGN phase started only recently. The outflow carries enough mass and energy to impact the host galaxy star formation on different spatial scales, highlighting the complexity of the AGN feeding and feedback cycle in its early stages.more » « less
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