English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We reason that, without physical fine-tuning, neither the supermassive blackholes (SMBHs) nor the stellar bulges can self-regulate or inter-regulate bydriving away already fallen cold gas to produce the observed correlationbetween them. We suggest an alternative scenario where the observed mass ratiosof the SMBHs to bulges reflect the angular momentum distribution of infallengas such that the mass reaching the stable accretion disc is a small fractionof that reaching the bulge region, averaged over the cosmological time scales.We test this scenario using high resolution, large-scale cosmologicalhydrodynamic simulations (without AGN feedback), assuming the angular momentumdistribution of gas landing in the bulge region to yield a Mestel disc that issupported by independent simulations resolving the Bondi radii of SMBHs. A massratio of $0.1-0.3\%$ between the very low angular momentum gas that free-fallsto the sub-parsec region to accrete to the SMBH and the overall star formationrate is found. This ratio is found to increase with increasing redshift towithin a factor of $\sim 2$, suggesting that the SMBH to bulge ratio is nearlyredshift independent, with a modest increase with redshift, a testableprediction. Furthermore, the duty cycle of active galactic nuclei (AGN) withhigh Eddington ratios is expected to increase significantly with redshift.Finally, while SMBHs and bulges are found to coevolve on $\sim 30-150$Myr timescales or longer, there is indication that, on shorer time scales, the SMBHaccretion rate and star formation may be less correlated.

the astrophysical journal. letters

Coevolution Between Supermassive Black Holes and Bulges Is Not Via  Internal Feedback Regulation But By Rationed Gas Supply Due To Angular  Momentum Distribution