Ann. Rev. Astron. and Astrophy., rejected
astro-ph/1101.0837

For a PDF version of the article, click here.

THERMAL AND NONTHERMAL RADIO GALAXIES

Robert Antonucci


Department of Physics, University of California, Santa Barbara


Abstract: Radio galaxies were discovered and mapped in the 1950s. The optical spectra showed little or no nuclear continuum light. Others revealed powerful high ionization emission lines, while others showed at most weak low-ionization emission lines. Quasars were found in the 1960s, and their spectra were dominated by powerful continuum radiation which was subsequently identified with optically thick thermal radiation from copious accretion flows, as well as high ionization narrow emission lines, and powerful broad permitted lines. By the 1980s, data from optical polarization and statistics of the radio properties required that many radio galaxies contain hidden Quasar nuclei, hidden from the line of sight by dusty, roughly toroidal gas distributions. The radio galaxies with hidden Quasars are referred to as "thermal."

Do all radio galaxies have powerful hidden Quasars? We now know the answer using arguments based on radio, infrared, optical and X-ray properties. Near the top of the radio luminosity function, for FRII, GPS, and CSS galaxies, the answer is yes. Below the top of the radio luminosity function, many do not. At low radio luminosities, most do not. Instead these "nonthermal" weakly-accreting galaxies are powerful emitters of kinetic energy in the form of synchrotron jets. They generally have weak low-ionization lines. This applies to all types of radio galaxy, big FR II doubles, as well as the small young GigaHertz-Peaked-Spectrum and Compact Steep Spectrum sources. Only a few FR I sources are of the thermal type.

Ann. Rev. Astron. and Astrophy., rejected.

Though the author was asked to write this review and spent much of a year doing it, then revised it according to some of the input from the ARAA editors, the editors rejected it. They demanded many ever-changing major and minor changes, many of which were described as "non-negotiable," before they would reconsider it. The editors emphasized that they have no problems with the scientific content, and that they had gone over the science "with a fine-toothed comb." Nevertheless they may have found some errors if they had given given the comb to an AGN person!

The editors emphasized that they were rejecting the paper on purely non-scientific grounds. I was informed for the first time after the rejection that the article had to be intelligible to "a beginning graduate student," in gross contradiction to statements in my invitation. That would have destroyed the paper. A typical minor request: the editors urged me to take advantage of the large page margins to add little comments and explanations which would better be put into footnotes. They apparently want it to look like a chapter in an Astro 1 book.

When ARAA calls you to write an article for them, remember that you may spend a year on it and then just have it rejected unless you make major changes that you may not agree with. If you write for them you could fall into this trap!


Table of Contents

TERMINOLOGY

BROADEST SKETCH
Where To Find Basic Information
Nature of Geometrical Unified Models
Types of Powerful Radio Source; Scope for Unification by Orientation
The Infrared Calorimeter

CLASSICAL DOUBLE, OR FR II RADIO SOURCES
Spectropolarimetry of Radio Galaxies and the Discovery of Hidden Quasars
Puzzling statistics on the radio properties of FR II radio galaxies and Quasars
The infrared calorimeter for visible and hidden FR II radio sources
Infrared properties of FR II Quasars and radio galaxies from the 3CR catalog
Nonthermal optical "compact cores"
X-rays

FR I RADIO GALAXIES
Radio Properties
Infrared
Optical
X-rays

SMALL SOURCES: COMPACT STEEP SPECTRUM AND GIGAHERTZ-PEAK SPECTRUM
Radio Properties
Infrared
Optical
X-rays

SUMMARY

REFERENCES

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