scholarly journals Local Swift-BAT active galactic nuclei prefer circumnuclear star formation

2017 ◽  
Vol 609 ◽  
pp. A9 ◽  
Author(s):  
D. Lutz ◽  
T. Shimizu ◽  
R. I. Davies ◽  
R. Herrera-Camus ◽  
E. Sturm ◽  
...  
Keyword(s):  
Black Hole ◽  
Star Formation ◽  
Active Galactic Nuclei ◽  
Spatial Scales ◽  
Galactic Nuclei ◽  
Far Infrared ◽  
Size Difference ◽  
Gas Reservoir ◽  
Large Samples ◽  
Structural Differences

We use Herschel data to analyze the size of the far-infrared 70 μm emission for z < 0.06 local samples of 277 hosts of Swift-BAT selected active galactic nuclei (AGN), and 515 comparison galaxies that are not detected by BAT. For modest far-infrared luminosities 8.5 <log  (LFIR [L⊙]) < 10.5, we find large scatter of half light radii Re,70 for both populations, but a typical Re,70≲ 1 kpc for the BAT hosts that is only half that of comparison galaxies of same far-infrared luminosity. The result mostly reflects a more compact distribution of star formation (and hence gas) in the AGN hosts, but compact AGN heated dust may contribute in some extremely AGN dominated systems. Our findings are in support of an AGN-host coevolution where accretion onto the central black hole and star formation are fed from the same gas reservoir, with more efficient black hole feeding if that reservoir is more concentrated. The significant scatter in the far-infrared sizes emphasizes that we are mostly probing spatial scales much larger than those of actual accretion, and that rapid accretion variations can smear the distinction between the AGN and comparison categories. Large samples are hence needed to detect structural differences that favor feeding of the black hole. No size difference between AGN host and comparison galaxies is observed at higher far-infrared luminosities log(LFIR [L⊙]) > 10.5 (star formation rates ≳6 M⊙ yr-1), possibly because these are typically reached in more compact regions.

scholarly journals The AGN-galaxy connection: Low-redshift benchmark & lessons learnt

2019 ◽  
Vol 15 (S352) ◽  
pp. 144-156
Author(s):  
Stéphanie Juneau
Keyword(s):  
Black Hole ◽  
Star Formation ◽  
Spatial Scales ◽  
Formation Rate ◽  
Cosmic Time ◽  
Individual Case ◽  
Host Galaxy ◽  
Gas Reservoir ◽  
Lessons Learnt

AbstractSeveral scenarios have been proposed to describe the physical connection between galaxies and their central active galactic nuclei (AGN). This connection could act on a range of spatial scales and vary across cosmic time. In these proceedings, we consider black hole and galaxy growth and whether that growth is affected by AGN feedback both based on statistical approaches – which reveal general population trends – and based on an individual case study – which gives us a more detailed insight on the physical processes at play. For the statistical approach, we showcase a low-redshift (0.04 < z < 0.2) SDSS sample with AGN classification based on a combination of emission-line diagnostic diagrams, and for which we account for sample selection by using a V/Vmax approach. The trends on the star formation rate - stellar mass (SFR – M*) plane suggest that the most likely connection is a common gas reservoir for star formation and AGN, and that they both decline as the gas reservoir is consumed. The trends established at low-redshift could act as a local benchmark against which to compare higher redshift studies. As a complementary approach, we use a detailed case study of a nearby AGN host with integral field spectroscopy from the VLT/MUSE instrument in order to spatially resolve the interplay between AGN feedback and the host galaxy. We find that the galaxy substructure likely plays a role by collimating and/or obscuring the outflows and radiation from the central engine. Ongoing and future work with 3D spectroscopy will enable us to learn more about galaxy and black hole coevolution. Lastly, we briefly discuss lessons learnt from both approaches.

scholarly journals A CENSUS OF BROAD-LINE ACTIVE GALACTIC NUCLEI IN NEARBY GALAXIES: COEVAL STAR FORMATION AND RAPID BLACK HOLE GROWTH

2013 ◽  
Vol 763 (2) ◽  
pp. 133 ◽  
Author(s):  
Jonathan R. Trump ◽  
Alexander D. Hsu ◽  
Jerome J. Fang ◽  
S. M. Faber ◽  
David C. Koo ◽  
...  
Keyword(s):  
Black Hole ◽  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Broad Line ◽  
Black Hole Growth ◽  
Nearby Galaxies ◽  
Hole Growth

scholarly journals Determining the radio active galactic nuclei contribution to the radio–far-infrared correlation using the black hole Fundamental Plane relation

2016 ◽  
Vol 460 (2) ◽  
pp. 1588-1597 ◽  
Author(s):  
O. Ivy Wong ◽  
M. J. Koss ◽  
K. Schawinski ◽  
A. D. Kapińska ◽  
I. Lamperti ◽  
...  
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Far Infrared ◽  
Fundamental Plane

scholarly journals Properties of X-ray detected far-IR AGN in the green valley

2019 ◽  
Vol 15 (S356) ◽  
pp. 147-151
Author(s):  
Antoine Mahoro ◽  
Mirjana Pović ◽  
Petri Väisänen ◽  
Pheneas Nkundabakura ◽  
Beatrice Nyiransengiyumva ◽  
...  
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Far Infrared ◽  
Mass Range ◽  
Infrared Emission ◽  
Active Galaxies ◽  
X Ray ◽  
Normal Galaxies ◽  
Using Data

AbstractIn this study, we analysed active galactic nuclei in the “green valley” by comparing active and non-active galaxies using data from the COSMOS field. We found that most of our X-ray detected active galactic nuclei with far-infrared emission have star formation rates higher than the ones of normal galaxies of the same stellar mass range.

scholarly journals Epicyclic Oscillations around Simpson–Visser Regular Black Holes and Wormholes

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 279
Author(s):  
Zdeněk Stuchlík ◽  
Jaroslav Vrba
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Active Galactic Nuclei ◽  
Observational Data ◽  
High Frequency ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Periodic Oscillations ◽  
High Length ◽  
Circular Geodesic

We study epicyclic oscillatory motion along circular geodesics of the Simpson–Visser meta-geometry describing in a unique way regular black-bounce black holes and reflection-symmetric wormholes by using a length parameter l. We give the frequencies of the orbital and epicyclic motion in a Keplerian disc with inner edge at the innermost circular geodesic located above the black hole outer horizon or on the our side of the wormhole. We use these frequencies in the epicyclic resonance version of the so-called geodesic models of high-frequency quasi-periodic oscillations (HF QPOs) observed in microquasars and around supermassive black holes in active galactic nuclei to test the ability of this meta-geometry to improve the fitting of HF QPOs observational data from the surrounding of supermassive black holes. We demonstrate that this is really possible for wormholes with sufficiently high length parameter l.

scholarly journals Constraining photoionization models with a reprojected optical diagnostic diagram

2020 ◽  
Vol 499 (4) ◽  
pp. 5749-5764 ◽  
Author(s):  
Xihan Ji ◽  
Renbin Yan
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Theoretical Models ◽  
Line Ratio ◽  
Star Forming ◽  
Optical Diagnostic ◽  
Diagnostic Diagram ◽  
Upper Limits ◽  
Nitrogen Abundance

ABSTRACT Optical diagnostic diagrams are powerful tools to separate different ionizing sources in galaxies. However, the model-constraining power of the most widely used diagrams is very limited and challenging to visualize. In addition, there have always been classification inconsistencies between diagrams based on different line ratios, and ambiguities between regions purely ionized by active galactic nuclei (AGNs) and composite regions. We present a simple reprojection of the 3D line ratio space composed of [N ii]λ6583/H α, [S ii]λλ6716, 6731/H α, and [O iii]λ5007/H β, which reveals its model-constraining power and removes the ambiguity for the true composite objects. It highlights the discrepancy between many theoretical models and the data loci. With this reprojection, we can put strong constraints on the photoionization models and the secondary nitrogen abundance prescription. We find that a single nitrogen prescription cannot fit both the star-forming locus and AGN locus simultaneously, with the latter requiring higher N/O ratios. The true composite regions stand separately from both models. We can compute the fractional AGN contributions for the composite regions, and define demarcations with specific upper limits on contamination from AGN or star formation. When the discrepancy about nitrogen prescriptions gets resolved in the future, it would also be possible to make robust metallicity measurements for composite regions and AGNs.

scholarly journals The Alignment of Disk and Black Hole Spins in Active Galactic Nuclei

1998 ◽  
Vol 506 (2) ◽  
pp. L97-L100 ◽  
Author(s):  
Priyamvada Natarajan ◽  
J. E. Pringle
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei
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