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Full-Text Articles in Physical Sciences and Mathematics
Magnetic Fields Threading Black Holes: Restrictions From General Relativity And Implications For Astrophysical Black Holes, David Garofalo
Magnetic Fields Threading Black Holes: Restrictions From General Relativity And Implications For Astrophysical Black Holes, David Garofalo
Faculty and Research Publications
The idea that black hole spin is instrumental in the generation of powerful jets in active galactic nuclei and X-ray binaries is arguably the most contentious claim in black hole astrophysics. Because jets are thought to originate in the context of electromagnetism, and the modeling of Maxwell fields in curved spacetime around black holes is challenging, various approximations are made in numerical simulations that fall under the guise of ‘ideal magnetohydrodynamics’. But the simplifications of this framework may struggle to capture relevant details of real astrophysical environments near black holes. In this work, we highlight tension between analytic and numerical …
Reconciling Ag-Star Formation, The Soltan Argument, And Meier's Paradox, David Garofalo, Matthew I. Kim, Damian J. Christian, Emily Hollingworth
Reconciling Ag-Star Formation, The Soltan Argument, And Meier's Paradox, David Garofalo, Matthew I. Kim, Damian J. Christian, Emily Hollingworth
Faculty and Research Publications
We provide a theoretical context for understanding the recent work of Kalfountzou et al. showing that star formation is enhanced at lower optical luminosity in radio-loud quasars. Our proposal for coupling the assumption of collimated FRII quasar-jet-induced star formation with lower accretion optical luminosity also explains the observed jet power peak in active galaxies at higher redshift compared to the peak in accretion power, doing so in a way that predicts the existence of a family of radio-quiet active galactic nuclei associated with rapidly spinning supermassive black holes at low redshift, as mounting observations suggest. The relevance of this work …
Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian
Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian
Faculty and Research Publications
The Fundamental Plane for black hole activity constitutes a tight correlation between jet power, X-ray luminosity, and black hole mass. Under the assumption that a Blandford–Znajek-type mechanism, which relies on black hole spin, contributes non-negligibly to jet production, the sufficiently small scatter in the Fundamental Plane shows that black hole spin differences of |Δa| ∼ 1 are not typical among the active galactic nuclei population. If – as it seems – radio-loud and radio-quiet objects are both faithful to the Fundamental Plane, models of black hole accretion in which the radio-loud/radio-quiet dichotomy is based on a spin dichotomy of a∼1/a∼0, …
The Jet-Disk Connection: Evidence For A Reinterpretation In Radio-Loud And Radio-Quiet Active Galactic Nuclei, David Garofalo
The Jet-Disk Connection: Evidence For A Reinterpretation In Radio-Loud And Radio-Quiet Active Galactic Nuclei, David Garofalo
Faculty and Research Publications
To constrain models of the jet-disc connection, we explore Eddington ratios reported in Foschini (2011) and interpret them in relation to the values in Sikora et al. across the active galactic nuclei population from radio loud quasars, their flat spectrum radio quasar subclass, the recently discovered gamma-ray loud narrow-line type 1 Seyfert galaxies, Fanaroff-Riley type I (FRI) radio galaxies and radio quiet quasars of the Palomar Green survey. While appeal to disc truncation in radiatively inefficient flow appears to explain the observed inverse relation between radio loudness and Eddington ratio in radio loud and radio quiet quasars, FR I objects, …