Multi-scale simulations of black hole accretion in barred galaxies

Jung, Manuel; Illenseer, Tobias F.; Duschl, W. J.

doi:10.1051/0004-6361/201731688

Cited by 6 publications

(3 citation statements)

References 127 publications

(197 reference statements)

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“…Unfortunately, there are no detailed simulations available that model particular accretion rate histories, which could put a hard constrain on t agn . Hence, we resort to small-scale simulations following the growth of black holes in a more global context (Di Johansson et al 2009a,b;Hopkins & Quataert 2010;Jung et al 2018). Our assumed cumulative time scale of t agn = 10 6 yr for a black hole that accretes higher than 70% of the Eddington accretion rate, lies within the uncertainties provided by such simulations, but at the lower end of the expected value (see also Sect.…”

Section: Intermittence Of Agn Activitymentioning

confidence: 81%

Major Mergers Are Not the Dominant Trigger for High-accretion AGNs at z ∼ 2

Marian

Jahnke

Mechtley

et al. 2019

ApJ

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Research over the past decade has shown diminishing empirical evidence for major galaxy mergers being a dominating or even important mechanism for the growth of supermassive black holes in galaxies and the triggering of optically or X-ray selected active galactic nuclei (AGN).We here for the first time test whether such a connection exists at least in the most 'plausible' part of parameter space for this mechanism: the highest specific accretion rate broad-line AGNs at the peak epoch of black hole activity around z = 2. To that end we examine 21 galaxies hosting a high accreting black hole (L/L edd > 0.7) observed with HST/WFC3 and 92 stellar mass-and redshiftmatched inactive galaxies taken from the CANDELS survey.We removed the AGN point sources from their host galaxies and avoided bias in visual classification by adding and then subtracting mock point sources to and from the comparison galaxies, producing matched residual structures for both sets. The resulting samples were joined, randomized, and subsequently visually ranked with respect to perceived strength of structural distortions by 10 experts. The ensuing individual rankings were combined into a consensus sequence and from this we derived merger fractions for both samples. With the merger fractions f m,agn = 0.24 ± 0.09 for the AGN host galaxy sample and f m,ina = 0.19 ± 0.04 for the inactive galaxies, we find no significant difference between the AGN host galaxies and inactive galaxies. Also, both samples display comparable fractions of diskdominated galaxies. These findings are consistent with previous studies for different AGN populations, and we conclude that even black hole growth at the highest specific accretion rates and at the peak of cosmic AGN activity is not predominantly caused by major mergers.Considering AGN and merger timescales we conclude that it is highly unlikely that a potential time lag could significantly affect our results. We also calculate the inverse view and infer that only ∼20% of all merging galaxies have high-accretion AGN activity during the ongoing merger. Eventually, we also find no significant connection between post-starburst galaxies and AGNs.

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Section: Intermittence Of Agn Activitymentioning

confidence: 81%

Major Mergers Are Not the Dominant Trigger for High-accretion AGNs at z ∼ 2

Marian

Jahnke

Mechtley

et al. 2019

ApJ

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“…However, based on the best estimates for accretion rate histories we have today (Di Matteo et al 2005;Johansson et al 2009aJohansson et al , 2009bHopkins & Quataert 2010;Jung et al 2018), we fix the time period in which an AGN accretes above λ edd >0.3 to t agn =10 7 yr. The inferred fractions of inactive merging galaxies that also host an AGN at any given time yield then = -+ f 0.06 m,ina&agn 0.02 0.01 and -+ 0.09 0.02 0.02 for t m =10 9 yr and 1.5×10 9 yr, respectively (Figure 6, dashed lines).…”

Section: Considering Agn and Merger Timescalesmentioning

confidence: 99%

A Significant Excess in Major Merger Rate for AGNs with the Highest Eddington Ratios at z < 0.2

Marian

Jahnke

Andika

et al. 2020

ApJ

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Observational studies are increasingly finding evidence against major mergers being the dominant mechanism responsible for triggering an active galactic nucleus (AGN). After studying the connection between major mergers and AGNs with the highest Eddington ratios at z = 2, we here expand our analysis to , exploring the same AGN parameter space. Using ESO VLT/FORS2 , , and color images, we examine the morphologies of 17 galaxies hosting AGNs with Eddington ratios , and 25 mass- and redshift-matched control galaxies. To match the appearance of the two samples, we add synthetic point sources to the inactive comparison galaxies. The combined sample of AGN and inactive galaxies was independently ranked by 19 experts with respect to the degree of morphological distortion. We combine the resulting individual rankings into multiple overall rankings, from which we derive the respective major merger fractions of the two samples. With a best estimate of f m,agn = 0.41 ± 0.12 for the AGN host galaxies and f m,ina = 0.08 ± 0.06 for the inactive galaxies, our results imply that our AGN host galaxies have a significantly higher merger rate, regardless of the observed wavelength or applied methodology. We conclude that although major mergers are an essential mechanism to trigger local high Eddington ratio AGNs at , the origin of of this specific AGN subpopulation still remains unclear.

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“…However, based on the best estimates for accretion rate histories we have today (Di Matteo et al 2005;Johansson et al 2009a,b;Hopkins & Quataert 2010;Jung et al 2018), we fix the time period in which an AGN accretes above λ edd > 0.3 to t agn = 10 7 yr. The inferred fractions of inactive merging galaxies that also host an AGN at any given time yield then f m,ina & agn = 0.06 +0.01 −0.02 and 0.09 +0.02 −0.02 for t m = 10 9 yr and 1.5×10 9 yr, respectively (Fig.…”

Section: Considering Agn and Merger Timescalesmentioning

confidence: 99%

A significant excess in major merger rate for AGNs with the highest Eddington ratios at z<0.2

Marian,

Jahnke,

Andika

et al. 2020

Preprint

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Observational studies are increasingly finding evidence against major mergers being the dominant mechanism responsible for triggering AGN. After studying the connection between major mergers and AGN with the highest Eddington ratios at z = 2, we here expand our analysis to z < 0.2, exploring the same AGN parameter space. Using ESO VLT/FORS2 B−, V − and color images, we examine the morphologies of 17 galaxies hosting AGNs with Eddington ratios λ edd > 0.3, and 25 mass-and redshift-matched control galaxies. To match the appearance of the two samples, we add synthetic point sources to the inactive comparison galaxies. The combined sample of AGN and inactive galaxies was independently ranked by 19 experts with respect to the degree of morphological distortion. We combine the resulting individual rankings into multiple overall rankings, from which we derive the respective major merger fractions of the two samples. With a best estimate of f m,agn = 0.41 ± 0.12 for the AGN host galaxies and f m,ina = 0.08 ± 0.06 for the inactive galaxies our results imply that our AGN host galaxies have a significantly higher merger rate, regardless of the observed wavelength or applied methodology. We conclude that although major mergers are an essential mechanism to trigger local high Eddington ratio AGNs at z < 0.2, the origin of 50% of this specific AGN subpopulation still remains unclear.

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Multi-scale simulations of black hole accretion in barred galaxies

Cited by 6 publications

References 127 publications

Major Mergers Are Not the Dominant Trigger for High-accretion AGNs at z ∼ 2

Major Mergers Are Not the Dominant Trigger for High-accretion AGNs at z ∼ 2

A Significant Excess in Major Merger Rate for AGNs with the Highest Eddington Ratios at z < 0.2

A significant excess in major merger rate for AGNs with the highest Eddington ratios at z<0.2

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