Nuclear ionised outflows in a sample of 30 local galaxies

AbstractUnderstanding active galactic nuclei (AGN) feedback is essential for building a coherent picture of the evolution of the super massive black hole and its host galaxy. To that end we have analysed the inner kiloparsec of a sample of 30 local AGN with spatially resolved optical spectroscopy. In this talk I will review the analysis of the ionised gas for the galaxies in our sample, including kinematical maps, emission line ratios and fluxes. The W80 kinematical index is used to trace outflows, and also to provide an estimate for the outflowing velocity. Electron densities, derived from the [S II] ΛΛ6716, 6731Å lines, along with Hα luminosities and the sizes of the outflowing regions are employed in estimates of the outflowing gas mass. We find a median mass outflow rate of Ṁ = 0.3 M⊙ yr-1 and median outflow power of log [P/(erg s-1)] = 40.4.

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Mass outflow constraints in active nuclei and quasars from X-ray spectroscopy

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308017882 ◽

2007 ◽

Vol 3 (S245) ◽

pp. 263-268

Author(s):

Tahir Yaqoob

Keyword(s):

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Host Galaxy ◽

Observational Constraints ◽

X Ray ◽

Outflow Rate ◽

Mass Outflow ◽

Physical Information

AbstractAbsorption in the X-ray spectra of active galactic nuclei from outflowing gas can be modeled to yield critical physical information on the outflows. The outflow rate of mass ejected back into the ISM of the host galaxy and the resulting feedback could potentially have an impact on evolution. We give a brief overview of the current observational constraints on the outflows that should be taken into account by models of evolution and feedback.

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The Starburst-AGN Connection: 3-D Structure of the Massive Gas Disk around the Nucleus

Symposium - International Astronomical Union ◽

10.1017/s0074180900207778 ◽

2003 ◽

Vol 208 ◽

pp. 463-464

Author(s):

Keiichi Wada ◽

Colin A. Norman

Keyword(s):

Black Hole ◽

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Interstellar Matter ◽

Viewing Angle ◽

Massive Black Hole ◽

Hydrodynamical Simulations ◽

Multi Phase ◽

Globally Stable ◽

High Column

The structure of obscuring matter in the environment of active galactic nuclei with associated nuclear starbursts is investigated using 3-D hydrodynamical simulations, in which the multi-phase inhomogeneous interstellar matter and its interaction with the supernovae are consistently followed. A globally stable, torus-like, but highly inhomogeneous and turbulent structure is found. To achieve the high column densities as suggested by observations of some Seyfert 2 galaxies with nuclear starbursts, the viewing angle should be larger than about 70° from the pole-on for a 108M⊙ massive black hole. We propose that nuclear starbursts and the mass of the black hole that determines the geometry of the obscuring torus.

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Active Galactic Nuclei: Variability at Many Wavelengths

Highlights of Astronomy ◽

10.1017/s1539299600018840 ◽

1998 ◽

Vol 11 (2) ◽

pp. 808-811

Author(s):

Thierry J.-L. Courvoisier

Keyword(s):

Black Hole ◽

Active Galactic Nuclei ◽

Thermal Emission ◽

Galactic Nuclei ◽

Gravitational Energy ◽

Heating Process ◽

Massive Black Hole ◽

Ultraviolet Emission ◽

X Ray ◽

Accretion Process

Active Galactic Nuclei (AGN) are thought to be powered by accretion onto a massive black hole. Understanding how gravitational energy freed by the infall of matter into the black hole is transferred to the radiating regions of the nucleus is one of the main challenges of AGN research. The question is made very complex by the presence of several cooling mechanisms with very diverse physical properties: We observe synchrotron radiation, thermal emission from hot dust, possibly thermal optical and ultraviolet emission and Comptonization processes in the X-ray domain. For each component the radiation is a signature of the cooling process rather than of the heating process. It is our hope that by observing the links and correlations between the emission of the different components we will be able to understand how they are interrelated and how they get their energy supply from the accretion process.

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Subaru Spectroscopy of the Giant Lyα Nebula around 1243+036

Symposium - International Astronomical Union ◽

10.1017/s007418090019789x ◽

2004 ◽

Vol 217 ◽

pp. 344-349

Author(s):

Youichi Ohyama ◽

Yoshiaki Taniguchi

Keyword(s):

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Major Axis ◽

Narrow Channel ◽

Host Galaxy ◽

Velocity Shift ◽

Spatially Resolved ◽

Systemic Velocity ◽

Halo Gas ◽

Powerful Radio Galaxy

We present our new spatially-resolved, optical spectroscopy of the giant Lyα nebula around the powerful radio galaxy 1243+036 (=4C+03.24) at z = 3.57. The nebula is extended over ~ 30 kpc from the nucleus, and forms a pair of cones or elongated bubbles. The high-velocity (~ −1000 km s−1; blueshifted with respect to the systemic velocity) Lyα-emitting components are detected at both sides of the nucleus along its major axis. We discuss possible origin of the nebula; 1) the shock-heated expanding bubble or outflowing cone associated with the superwind activity of the host galaxy, 2) halo gas photoionized by the anisotropic radiation from the active galactic nuclei (AGN) and 3) the jet-induced star-formation or shock. The last possibility may not be likely because Lyα emission is distributed out of the narrow channel of the radio jet. We show that the superwind model is most plausible since it can explain both the characteristics of the morphology (size and shape) and the kinematical structures (velocity shift and line width) of the nebula although the photoionization by AGN may contribute to the excitation to some extent.

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Black hole mass estimation for active galactic nuclei from a new angle

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz1546 ◽

2019 ◽

Vol 487 (3) ◽

pp. 3404-3418 ◽

Cited By ~ 9

Author(s):

Dalya Baron ◽

Brice Ménard

Keyword(s):

Black Hole ◽

Active Galactic Nuclei ◽

Cosmic Time ◽

Galactic Nuclei ◽

Host Galaxy ◽

Black Hole Mass ◽

Mass Estimation ◽

Line Region

Abstract The scaling relations between supermassive black holes and their host galaxy properties are of fundamental importance in the context black hole-host galaxy co-evolution throughout cosmic time. In this work, we use a novel algorithm that identifies smooth trends in complex data sets and apply it to a sample of 2000 type 1 active galactic nuclei (AGNs) spectra. We detect a sequence in emission line shapes and strengths which reveals a correlation between the narrow L([O iii])/L(H β) line ratio and the width of the broad H α. This scaling relation ties the kinematics of the gas clouds in the broad line region to the ionization state of the narrow line region, connecting the properties of gas clouds kiloparsecs away from the black hole to material gravitationally bound to it on sub-parsec scales. This relation can be used to estimate black hole masses from narrow emission lines only. It therefore enables black hole mass estimation for obscured type 2 AGNs and allows us to explore the connection between black holes and host galaxy properties for thousands of objects, well beyond the local Universe. Using this technique, we present the MBH–σ and MBH–M* scaling relations for a sample of about 10 000 type 2 AGNs from Sloan Digital Sky Survey. These relations are remarkably consistent with those observed for type 1 AGNs, suggesting that this new method may perform as reliably as the classical estimate used in non-obscured type 1 AGNs. These findings open a new window for studies of black hole-host galaxy co-evolution throughout cosmic time.

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Black Hole Models of Quasars

Symposium - International Astronomical Union ◽

10.1017/s0074180900153021 ◽

1986 ◽

Vol 119 ◽

pp. 359-369 ◽

Cited By ~ 2

Author(s):

R. D. Blandford

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Cosmic Time ◽

Galactic Nuclei ◽

Seyfert Galaxies ◽

Massive Black Hole ◽

Binary Black Holes ◽

Electron Positron ◽

Gas Supply

Observations of active galactic nuclei are interpreted in terms of a theoretical model involving accretion onto a massive black hole. Optical quasars and Seyfert galaxies are associated with holes accreting near the Eddington rate and radio galaxies with sub-critical accretion. It is argued that magnetic fields are largely responsible for extracting energy and angular momentum from black holes and disks. Recent studies of electron-positron pair plasmas and their possible role in establishing the emergent X-ray spectrum are reviewed. The main evolutionary properties of active galactic nuclei can be interpreted in terms of a simple model in which black holes accrete gas at a rate dictated by the rate of gas supply which decreases with cosmic time. It may be worth searching for eclipsing binary black holes in lower power Seyferts.

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A search for H2O masers in 100 active dwarf galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2730 ◽

2020 ◽

Vol 499 (1) ◽

pp. 1233-1249

Author(s):

M J Rosenthal ◽

I Zaw

Keyword(s):

Black Hole ◽

Active Galactic Nuclei ◽

Detection Rate ◽

Dwarf Galaxies ◽

Galactic Nuclei ◽

Optical Emission ◽

Massive Black Hole ◽

Massive Galaxies ◽

Low Mass ◽

Green Bank Telescope

ABSTRACT We present the results of the first dedicated survey for 22 GHz H2O maser emission in dwarf galaxies outside of the Local Group, with the aim of discovering disc masers. Studies of disc masers yield accurate and precise measurements of black hole (BH) mass, and such measurements in dwarf galaxies would be key to understanding the low-mass end of BH–galaxy coevolution. We used the Green Bank Telescope to survey 100 nearby (z ≲ 0.055) dwarf galaxies (M* ≲ 109.5 M⊙) with optical emission line ratios indicative of accretion on to a massive black hole. We detected no new masers down to a limit of ∼12 mJy (5σ). We compared the properties of our sample with those of ∼1850 known detections and non-detections in massive galaxies. We find, in agreement with previous studies, that masers are preferentially hosted by Seyferts and highly obscured, [O iii]-bright active galactic nuclei (AGNs). Our sample has fewer Seyferts, is less obscured, and is [O iii]-faint. Though the overall maser detection rate is ∼3 per cent in massive galaxies, the predicted rate for our sample, weighted by its optical properties, is ∼0.6–1.7 per cent, corresponding to a probability of making no detections of ∼20–50 per cent. We also found a slight increase in the detection rate with increased stellar mass in previously surveyed galaxies. However, further observations are required to discern whether there is an intrinsic difference between the maser fraction in active dwarf galaxies and in their massive counterparts for the same AGN properties.

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AGN Obscuration and the Unified Model

Advances in Astronomy ◽

10.1155/2012/782030 ◽

2012 ◽

Vol 2012 ◽

pp. 1-17 ◽

Cited By ~ 59

Author(s):

Stefano Bianchi ◽

Roberto Maiolino ◽

Guido Risaliti

Keyword(s):

Black Hole ◽

Active Galactic Nuclei ◽

Galactic Nuclei ◽

Line Of Sight ◽

Host Galaxy ◽

Geometrical Distribution ◽

Orientation Effects ◽

Open Issues

Unification Models of Active Galactic Nuclei postulate that all the observed differences between type 1 and type 2 objects are due to orientation effects with respect to the line of sight to the observer. The key ingredient of these models is the obscuring medium, historically envisaged as a toroidal structure on a parsec scale. However, many results obtained in the last few years are clearly showing the need for a more complex geometrical distribution of the absorbing media. In this paper, we review the various pieces of evidence for obscuring media on different scales, from the vicinity of the black hole to the host galaxy, in order to picture an updated unification scenario explaining the complex observed phenomenology. We conclude by mentioning some of the open issues.

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