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“THE GOAL of this work is to explore the interplay of different physical processes that determine the masses of seed BHs, the triggering of AGN activity and the efficiency of gas accretion during the active phases of BHs, with the aim of understanding the physical origin of the observed downsizing trend in BH growth.” (BH = black hole; AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn

STELLAR SEEDING. Our model “does not produce enough very luminous QSOs at high redshift (z > 5). Our third, main conclusion is that a heavy seeding mechanism for black holes provides a physically motivated way to increase the predicted number density of very luminous QSOs at high redshift, in line with observations.” (QSO = Quasi Stellar Objects). https://lnkd.in/d9JV8md View in LinkedIn

BLACK HOLE ACCRETION. “However, the observational situation remains murky. Observational studies have repeatedly failed to find evidence for a statistically significant enhancement of merger-related signatures, such as close pairs or morphological disturbance.” https://lnkd.in/d9JV8md View in LinkedIn

TWO FACTORS. “Our results therefore favour a ‘hybrid’ picture in which major merger events are the main driver of luminous AGN, especially at high redshift, while disc instabilities are the main mechanism powering moderately luminous Seyfert galaxies at low redshift.” (AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn

BLACK HOLE GROWTH. “Mergers appear to be a physically well-motivated candidate for producing this dramatic effect, and semi-empirical calculations have shown that there is a statistical consistency between the observed merger rate and the observed AGN duty cycle and luminosity function (LF), suggesting that it is at least possible that these processes are causally linked.” (AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn

How a feather in the wild, the rain, and mud, can retain such a perfect form has to do with two things: its barbed structure which hooks the pieces in place, and the fine coating of natural water-resistant talcum powder from the bird’s skin. View in LinkedIn

The microclimate afforded by trees is physically similar to swimming in the sea and coming across layers of unmixed water at different temperatures. View in LinkedIn

BACTERIAL IMMUNITY. “Together with the Cas enzymes of the CRISPR system, these spacers allow the bacteria to recognize non-self DNA and remove it before it is incorporated into the genome. Hence, the bacteria can have "memory" of a previous infiltration, which helps it respond to any future attempts.” The basis of our new-found gene editing ability. https://lnkd.in/dSwmRvM View in LinkedIn

NEW LAWS. “The lowest temperature currently achieved in laboratories is of the order of picokelvins, i.e. many orders lower than the average temperature of the universe T = 2.73 K. At these temperatures we gain access to a world of exotic phenomena and physics that was once ordinary becomes extraordinary.” The laws of physics at extreme temperatures, densities and pressures are unknown, all common in the cosmos. https://lnkd.in/d63FZYV View in LinkedIn

APPRECIABLE EFFECT. “Gas accretion on to BHs due to disc instabilities seems to be a non-negligible trigger mechanism for moderately luminous AGN with BH masses 10(7) < M• < 10(8) M⊙ at low redshift.” (BH = black hole; AGN = active galactic nuclei). https://lnkd.in/d9JV8md View in LinkedIn