Obscuring Fraction of Active Galactic Nuclei Implied by Supernova and Radiative Feedbacks

Kawakatu, Nozomu; Wada, Keiichi; Ichikawa, Kohei

doi:10.3847/1538-4357/ab5f60

Cited by 26 publications

(16 citation statements)

References 127 publications

(165 reference statements)

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“…We assume that η = 10 −3 M −1 and C * = 3 × 10 −8 yr −1 , following Kawakatu & Wada (2008). We note that this disk model (see also Kawakatu et al 2020) is supported by recent observations. For example, Nagai & Kawakatu (2021) detected diffuse synchrotron emission that is associated with star formation in the circumnuclear disk of NGC 1275.…”

Section: Unstable Diskmentioning

confidence: 55%

Massive Molecular Gas as a Fuel Tank for Active Galactic Nuclei Feedback in Central Cluster Galaxies

Fujita,

Kawakatu,

Nagai

2021

Preprint

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Massive molecular gas has been discovered in giant elliptical galaxies at the centers of galaxy clusters. To reveal its role in AGN feedback in those galaxies, we construct a semi-analytic model of gas circulation. This model especially focuses on the massive molecular gas (interstellar cold gas on a scale of ∼ 10 kpc) and the circumnuclear disk ( 0.5 kpc). We consider the destruction of the interstellar cold gas by star formation and the gravitational instability for the circumnuclear disk. Our model can reproduce the basic properties of the interstellar cold gas and the circumnuclear disk such as their masses. We also find that the circumnuclear disk tends to stay at the boundary between stable and unstable states. This works as an 'adjusting valve' that regulates mass accretion toward the supermassive black hole. On the other hand, the interstellar cold gas serves as a 'fuel tank' in the AGN feedback. Even if the cooling of the galactic hot gas is prevented, the interstellar cold gas can sustain the AGN activities for 0.5 Gyr. We also confirm that the small entropy of the hot gas ( 30 keV cm 2 ) or the short cooling time ( 1 Gyr) is a critical condition for the existence of the massive molecular gas in the galaxy. The dissipation time of the interstellar cold gas may be related to the critical cooling time.

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Section: Unstable Diskmentioning

confidence: 55%

Massive Molecular Gas as a Fuel Tank for Active Galactic Nuclei Feedback in Central Cluster Galaxies

Fujita,

Kawakatu,

Nagai

2021

Preprint

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“…Kawakatu et al ( 2020) provided a turbulent velocity (v t ) in the CND (see equation ( 8) in Kawakatu et al (2020)) based on the SN-driven turbulence model, where the turbulence is driven by the energy input from the SN explosion. For NGC 1275, we take a molecular gas mass (M gas ) of ∼ 10 8 M ⊙ (Nagai et al 2019), star formation rate (SFR) of 3 M ⊙ yr −1 (Silver et al 1998), black hole mass (M BH ) of 1 × 10 9 M ⊙ (Nagai et al 2019), and the disk radius (r) of 100 pc (Nagai et al 2019).…”

Section: Comparison With the Sn-driven Turbulence Modelmentioning

confidence: 99%

Diffuse Synchrotron Emission Associated with the Starburst in the Circumnuclear Disk of NGC 1275

Nagai,

Kawakatu

2021

Preprint

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Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations found a positive correlation between the mass of dense molecular gas in the circumnuclear disks (CNDs) and accretion rate to the active galactic nuclei (AGNs). This indicates that star formation activity in the CNDs is essential for triggering the accretion of mass to AGNs. Although the starburst-driven turbulence is a key mechanism for the transfer of angular momentum and the resultant mass accretion from the CND scale to the inner radius, the observational evidence is lacking. We report the very-longbaseline-interferometry (VLBI) detection of the diffuse synchrotron emission on a scale of several tens-pc coinciding spatially with the molecular gas disk recently discovered by ALMA observations in NGC 1275. The synchrotron emissions are most likely resulted from the relativistic electrons produced by the supernova explosions. This is an unambiguous evidence of the star formation activity in a CND. The turbulent velocity and the scale height of the CND predicted from the supernova-driven turbulence model agree with the observations, although the model-predicted accretion rate disagrees with the bolometric luminosity. This might indicate that additional mechanisms to enhance the turbulence is required for the inner disk. We discuss the multiphase nature of the CND by combining the information of the CO emission, synchrotron emission, and free-free absorption.

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“…In Kawakatu et al (2020), we investigated the structure at 10 pc scale obscuring the circumnuclear discs (CNDs) by considering the SN feedbacks from nuclear starburst and the effect of anisotropic radiation pressure. We explored how structures of 1-10 pc dusty CNDs depend on the BH mass (M BH ), AGN luminosity (L AGN ), and physical properties of CNDs.…”

Section: How Do the Agn And Starburst Feedback Contribute To Obscuratmentioning

confidence: 99%

“…), and 3) How does the AGN plus starburst feedback contribute to the obscuration? (Kawakatu et al (2020)).…”

Section: Introductionmentioning

confidence: 99%

Nature of inflows and outflows in AGNs

Wada¹,

Kudoh

Yutani³

et al. 2019

Proc. IAU

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Despite many theoretical studies and observations, we still do not fully understand the feeding mechanism in AGNs even in nearby galaxies, and how feedback from AGNs affects the gas dynamics itself in the galactic central regions. In this article, we summarize our recent theoretical studies and preliminary results in terms of the mass inflow and outflows on sub-parsec to 100 parsecs scales around AGNs. We introduce different studies: 1) How do galaxy-galaxy mergers trigger AGN activity and obscuration?, 2) How do the radiative feedback affect formation of outflows and obscuration of the nucleus? and 3) How does the AGN plus starburst feedback contribute to the obscuration?

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Obscuring Fraction of Active Galactic Nuclei Implied by Supernova and Radiative Feedbacks

Cited by 26 publications

References 127 publications

Massive Molecular Gas as a Fuel Tank for Active Galactic Nuclei Feedback in Central Cluster Galaxies

Massive Molecular Gas as a Fuel Tank for Active Galactic Nuclei Feedback in Central Cluster Galaxies

Diffuse Synchrotron Emission Associated with the Starburst in the Circumnuclear Disk of NGC 1275

Nature of inflows and outflows in AGNs

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