Why Radio Quiet Quasars are Preferred over Radio Loud Quasars Regardless of Environment and Redshift



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© 2020. The American Astronomical Society. All rights reserved.. Evidence has accumulated suggesting the clustering of radio loud quasars (RLQs) is greater than for radio quiet quasars. We interpret these results in a context in which the fraction of RLQ formation is f RLQ ≤ f RQQ compared to that for radio quiet quasars for all environments and redshifts. Because we assume that post-merger cold gas onto large black holes produces either a radio loud or a radio quiet quasar, we show that for the largest black hole masses that live in the largest dark matter halos, f RLQ approaches 0.5 from below but does not exceed it, such that in rich clusters the formation of an RLQ tends to be equally likely to occur as a radio quiet quasar. In dark matter halos with smaller mass, by contrast, radio quiet quasars are more likely to form and the likelihood increases inversely with dark matter halo mass. As a result, averaging over a population of radio loud and radio quiet quasars will necessarily generate lower average black hole masses for the radio quiet subgroup. Hence, despite the fact that the formation of radio quiet quasars is preferred over RLQs in any environment, at any mass scale, at any luminosity, or redshift, averaging over a range of RLQs will give the appearance that they are preferred in cluster environments over radio quiet quasars. We show how this also accounts for the order of magnitude difference in the total number of jetted active galaxies compared to nonjetted counterparts.

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Astrophysical Journal

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