Radio Galaxy Zoo Talk

Active Galactic Nuclei and Quasars: Why Still a Puzzle after 50 years?

  • JeanTate by JeanTate

    Antonucci (2015). Fascinating, not least because of who the (sole!) author is:

    The first part of this article is a historical and physical introduction to quasars and their close cousins, called Active Galactic Nuclei (AGN). In the second part, I argue that our progress in understanding them has been unsatisfactory and in fact somewhat illusory since their discovery fifty years ago, and that much of the reason is a pervasive lack of critical thinking in the research community. It would be very surprising if other fields do not suffer similar failings.

    With this (giant!) caveat - "I will only discuss the relativistic regions of AGN in this essay" - here are his five "“BREAKTHROUGHS,” ROBUST, DUBIOUS, AND FALSIFIED" (section 3):

    1. Prediction of Leftover Supermassive Black Holes: Robust Confirmation, 1980s-1990s
    2. The Unified Model, Part 1: Relativistic beaming: Robust Confirmation, 1980s
    3. The Unified Model, Part 2: Hidden Nuclei: Discovery and Robust Confirmation, 1980s and 1990s
    4. The putative quasi-static accretion disk of inflowing matter. Falsified, 1980s–present
    5. Secrets of the X-ray Spectrum: Mapping out the Kerr potential Dubious, 1990s–present

    #4 was an eye-opener for me ... is he right?

    He also poses a series of questions in Section 2; my fave is "We find that very powerful radio (and optical, and X-ray) synchrotron-emitting plasma jets emerge from the central sub-parsec cores of some of them — but mysteriously, just the ones which reside in elliptical galaxy hosts! Why is that? Why should an engine of solar-system size care what type of galaxy it resides in?"

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