Book contents
- Frontmatter
- Contents
- Preface
- Introduction
- 1 Distances of Quasars
- 2 The Battle Over Statistics
- 3 Galaxies Visibly Connected to Quasars
- 4 Certain Galaxies with Many Quasars
- 5 Distribution of Quasars in Space
- 6 Galaxies with Excess Redshift
- 7 Small Excess Redshifts, the Local Group of Galaxies, and Quantization of Redshifts
- 8 Correcting Intrinsic Redshifts and Identifying Hydrogen Clouds Within Nearby Groups of Galaxies
- 9 Ejection from Galaxies
- 10 The Sociology of the Controversy
- 11 Interpretations
- Glossary
- Index
9 - Ejection from Galaxies
Published online by Cambridge University Press: 01 June 2011
- Frontmatter
- Contents
- Preface
- Introduction
- 1 Distances of Quasars
- 2 The Battle Over Statistics
- 3 Galaxies Visibly Connected to Quasars
- 4 Certain Galaxies with Many Quasars
- 5 Distribution of Quasars in Space
- 6 Galaxies with Excess Redshift
- 7 Small Excess Redshifts, the Local Group of Galaxies, and Quantization of Redshifts
- 8 Correcting Intrinsic Redshifts and Identifying Hydrogen Clouds Within Nearby Groups of Galaxies
- 9 Ejection from Galaxies
- 10 The Sociology of the Controversy
- 11 Interpretations
- Glossary
- Index
Summary
From the first time that people started to look closely at galaxies it was clear that galaxies could eject material. By the early 1900's moderate-sized telescopes and the advent of photography had enabled individual galaxies to be examined. Among the brightest of these galaxies was M87 (Messier 87. also called NGC 4486 and, with the coming of radio astronomy, Virgo A). A photograph published by Heber Curtis in 1918 showed a luminous spike originating from its nucleus. It was like a fountain of material emerging from the center of the galaxy. It was always clear that it was ejected and it was always called the “jet” in M87.
But then it was ignored. A generation later, during the 1950's, radio astronomy began to explore the skies and immediately discovered unavoidable evidence of ejection outward from the nuclei of many different galaxies. In particular, a jet of radio emitting material was discovered emerging from the nucleus of M87. It was coincident with the original optical jet. But radio astronomers were only easy with the concept of charged particles (electrons, for example) bending in magnetic fields and therefore emitting the energy (synchrotron radiation) which they detected with their receivers. Therefore they classified the jet in M87 as “optical synchrotron” radiation, implying that it was a hot gas, would expand and dissipate and thus, if you waited a little while, the problem would go away.
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- Information
- Quasars, Redshifts and Controversies , pp. 133 - 164Publisher: Cambridge University PressPrint publication year: 1988