Book contents
- Frontmatter
- Contents
- List of figures
- List of tables
- Preface
- Acknowledgments
- 1 Astronomy through the centuries
- 2 Electromagnetic radiation
- 3 Coordinate systems and charts
- 4 Gravity, celestial motions, and time
- 5 Telescopes
- 6 Detectors and statistics
- 7 Multiple telescope interferometry
- 8 Point-like and extended sources
- 9 Properties and distances of celestial objects
- 10 Absorption and scattering of photons
- 11 Spectra of electromagnetic radiation
- 12 Astronomy beyond photons
- Credits, further reading, and references
- Appendix: Units, symbols, and values
- Index
12 - Astronomy beyond photons
Published online by Cambridge University Press: 05 June 2012
- Frontmatter
- Contents
- List of figures
- List of tables
- Preface
- Acknowledgments
- 1 Astronomy through the centuries
- 2 Electromagnetic radiation
- 3 Coordinate systems and charts
- 4 Gravity, celestial motions, and time
- 5 Telescopes
- 6 Detectors and statistics
- 7 Multiple telescope interferometry
- 8 Point-like and extended sources
- 9 Properties and distances of celestial objects
- 10 Absorption and scattering of photons
- 11 Spectra of electromagnetic radiation
- 12 Astronomy beyond photons
- Credits, further reading, and references
- Appendix: Units, symbols, and values
- Index
Summary
What we learn in this chapter
Major new facilities that detect signals from the cosmos other than electromagnetic radiation are bringing new fields into the forefront of astronomy. Neutrino observatories study the energy-producing thermonuclear reactions at the center of the sun with detectors utilizing chlorine, gallium, and pure water, the latter making use of Cerenkov radiation from recoil electrons. The pioneering Homestake mine experiment and the huge Super-Kamiokande experiment are important examples. Neutrino astronomers detected a flash of neutrinos from the collapse of a star in the supernova SN 1987A and hope to see extragalactic flashes from gamma-ray bursts.
Cosmic ray observatories study highly energetic charged particles (mostly protons) entering the atmosphere from the Galaxy and probably extragalactic sources. The element abundances at energies ≳1 GeV provide a lifetime (∼107 yr) for their storage in the Galaxy. The highest energy particles initiate extensive air showers (EAS) of particles in the earth's atmosphere, facilitating their study with detector arrays covering 103 km2, such as the HiRes Fly's Eye and the Auger project. The most energetic such particles, ∼10 to 300 EeV (1019 to 3 × 1020 eV) are probably extragalactic in origin and may arrive from the approximate directions of their origin. Small EAS initiated by TeV gamma rays high in the atmosphere produce Cerenkov radiation observed with ground based mirror-PMT systems, i.e., TeV photon astronomy.
Gravitational waves (G waves) are predicted by Einstein's general theory of relativity and searches for them have so far not reached the needed sensitivities. […]
- Type
- Chapter
- Information
- Astronomy MethodsA Physical Approach to Astronomical Observations, pp. 378 - 414Publisher: Cambridge University PressPrint publication year: 2003