Multimessenger Astronomy

Foreword by Rainer Weiss (Nobel Laureate)

Introduction

The electromagnetic spectrum based on a diagram with the different wavelength ranges explained, and the beginning of observations for each range marked as a small range of dates within the XX century. In addition a second diagram will illustrate the non-electromagnetic forms of detection of astronomical sources and the dates of initiation of each of them. 

1. Optical astronomy.

The optical telescope . Spectrograph. Photographic plate. CCD.

Important telescopes (Very brief resumé of history to set a scene, including earliest telescopes: Lippershey, Galileo , Newton, Cassegrain,  Earl of Rosse, Herschel, Mt. Wilson, Mt. Palomar, Hubble Space Telescope, Adaptive Optics).

Basic results: Images of star clusters, interstellar emitting gas, galaxies, galaxy clusters. Spectra of outstanding objects. Velocities, chemical compositions of objects, temperaturas, gravitational fields. Limitations (dust,  very high and very low temperature objects, non-thermal emission).

2. Radioastronomy

Jansky, radiostatic from Milky Way. 2nd World War development of radio techniques and receivers. Radio telescopes : Large dishes at Jodrell Bank, Green Bank, Effelsberg, Arecibo. Interferometers: basis, interferometers: Cambridge, Dwingeloo, VLA. High frequencies, (centimetre wave and millimetre wave astronomy). VLBI.

Results: Sun, Jupiter, Centre of Galaxy (Sag A), Supernova remnants, Quasars, pulsars, jets, non-thermal sources in general, Cosmic Microwave Background.  HI, molecules (notably H₂).

3.  Infrared Astronomy

Development of infrared detectors in the 1960's. Ground based infrared telescopes SIRTF, UKIRT. Satellites IRAS, Spitzer (SIRTF).

Infrared astronomy from aircraft, Kuiper and Sofía observatories; Solar IR observations from aircraft, Lear Jet, Concorde eclipse observations.

Basic results: dust penetration, galaxy and star formation, planet detection.

4. Ultraviolet astronomy.

Ozone and nitrogen impede direct observations in most of the UV from the ground. Balloons, rockets, and satellites needed.

NASA's orbiting astronomical observatories were dedicated partly to UV astronomy. OAO3 ("Copernicus") measured interstellar deuterium), International Ultraviolet Explorer (NASA, ESA, plus UK) measured spectra of many astronomical sources. Halley's comet, planets, quasars, hot stars.  Extreme Ultraviolet explorer, and more recently GALEX, maps of hot components of galaxies.

5. X-ray astronomy

First detections using rocket equipment in 1962 Sco X-1 and the Crab Nebula. Used Geiger counters as detectors. 35 sources by 1965. Cygnus X-1, first stellar mass black hole.

Early satellites HEAO-1 1977, and Einstein. Detected radio pulsars, pulsars, galaxies, quasars, auroras on planets and the X-ray background. Chandra X-ray observatory 1999, and XMM-Newton. X-ray binaries, and supermassive black holes at galaxy centres.

6.Gamma-ray astronomy

First detections with Vela satellites 1960's designed to detect nuclear explosions)  detected cosmic gamma ray bursts from distant space. Also discovered from Sun by solar orbiter. Series of satellites, notably OSO-3 (NASA) Cos- B (ESA) through to the Compton Gamma Ray observatory in the 1990's. More recently INTEGRAL and AGILE in Europe and Fermi in US.  Ground based gamma-ray telescopes using Cherenkov effect from particle showers produced by high energy gamma rays, (HESS, MAGIC, CTA). Recent catalogue from HESS of Galactic plane sources. High energy gamma ray bursts produced in violent events (hypernovae, neutron star and black hole mergers etc.) Combination and relation of gamma rays with cosmic rays (see also neutrinos).

In 2017 a gamma-ray burst was identified with a gravitational wave source as produced by merging neutron star binary.

7.Neutrino astronomy

Neutrinos first detected in  1956 Cowan and Reines (Nobel) in reactor. First solar neutrinos detected by Davis(Nobel with Koshiba) and Bahcall. Terrestrial atmospheric neutrinos in 1965.

Underwater experiments DUMAND, (Deep underwater muon and neutrino detector) Baikal lake (used three strings to find muon trajectories). Under ice experiments AMANDA in antartica ( not deep enough to reconstruct tracks) then extended to 2km and tracks recorded., and succeeded by IceCube (2005). In 2017 IceCube detected a high energy neutrino traceable to a blazar 3.7 billion light years away. (combined with MAGIC gamma ray detection).

8. Gravitational wave astronomy

Indirect detection of gravitational waves in binary pulsar orbital decay (Taylor and Hulse), and subsequent similar detections.

Direct detectors of gravitational waves: LIGO

1962. Gerstenshtein and Pustovoit suggested use of laser interferometery for GW detection.

Laser interferometer. Rainer Weiss realised in the 1970's that a laser interferometer mode of detecting gravitational waves had the potential for success. Kip Thorne worked on the theory of their production by astronomical sources . LIGO gradually adopted by NSF in 1990's, collaboration with Ron Drever (later excluded for bad managment!). Technique adopted  from GEO600 detector at Hannover.

First operation of LIGO from 2002 to 2010, without success. Advanced LIGO operated in Feb. 2015 at Livingstone and Hanford. First detection on 14th September 2015 (two 30 solar mass black holes merging at 1.3 billion light years from Earth). Since then

9. Cosmic ray astronomy.

Cosmic rays discovered by Father Wulf, (Dutch) , Pacini (Italian), Hess (Austrian) between 1908 and 1912, using electroscope discharge, followed by Kholhörster (German) Pacini used underwater detection to show particles came from above, Hess and KH flew in balloon. Term cosmic rays given by Millikan in 1926.

Cosmic rays as leading elements for probing physics between 1920's and 1950's. (positron, muon,  pion, Kaon, lambda.hyperon)

Composition of cosmic rays (compared with solar and stellar abundances have more LiBeB. Comparison of particle with cosmic gamma-rays. (same sources, gamma rays permit source identification).

AMS and cosmic ray composition. AMS and the hunt for primordial antimatter.

10. Cosmology and particle physics: interaction of the largest and smallest scales in the universe.

Dark matter: astronomical clues. Dark matter searches.

Matter antimatter asymmetry. The very early universe. Telescopes and accelerators.

Dark energy.

11. In the form of a brief appendix: meteorites and cosmochemistry