Encyclopedia of Astrobiology

2015 Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James (Jim) CleavesII, Daniele L. Pinti, José Cernicharo Quintanilla, Daniel Rouan, Tilman Spohn, Stéphane Tirard, Michel Viso

Radio Astronomy

  • Philippe Zarka
Reference work entry
DOI: https://doi.org/10.1007/978-3-662-44185-5_1339

Synonyms

Definition

Radio astronomy describes the techniques employed, from antennas to receivers, to receive and measure long wavelength electromagnetic radiation (radio waves). The specificity of these techniques, by contrast with optical or high-energy astronomy, is the coherent detection of the wave electric field (amplitude E and phase φ), instead of the mere intensity (<E2>Δt). This makes  interferometry easier, compensating for the poor angular resolution intrinsic to long wavelengths. Radio emissions are produced by processes often different from those in the optical range. These include cyclotron and synchrotron emissions, bremstrahlung, molecular and atomic transitions, and various coherent processes. Radio astronomy is especially adapted to probing  plasmas (ionized/magnetized mater) as well as cold matter.

History

Radio astronomy is a recent branch of astronomy, born in the 1930s at low frequencies (22 MHz) with K. Jansky’s detection of lightning...

Keywords

Antennas Arrays Coherence Coherent detection Correlation Heterodyne Interferometry Noise Plasmas Polarization Propagation Radio waves Receivers 
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Notes

Notations and Acronyms

ALMA

Atacama large millimeter/submillimeter array

COBE

Cosmic background explorer

DM

Dispersion measure: DM = ∫LNe dL

DSP

Digital signal processor

fce

Cyclotron frequency: fce = eB/2πme2πme; fce (Hz) = 2.8 × 1010 B (T)

FFT

Fast fourier transform

FIR

Far infrared

fpe

Plasma frequency: fpe = (1/2π) (Nee2ome)1/2; fpe (Hz) = 9 Ne1/2 (m−3)

FOV

Field of view

FPA

Focal plane array

FPGA

Field programmable gate array

IRAM

Institut de radio astronomie millimétrique

LH

Left-handed (Circular or elliptical polarization)

LOFAR

Low frequency array

LWA

Long wavelength array

mm/sub-mm

Millimeter/submillimeter wavelength ranges

RAE

Radio astronomy explorer 1 and 2 satellites (1968–1973)

RFI

Radio frequency interference

RH

Right-handed (Circular or elliptical polarization)

SKA

Square kilometer array

UTR-2

Ukrainian T-shape radiotelescope – Mark II

VLBI

Very long baseline interferometry

References and Further Reading

  1. Burke B, Graham-Smith F (1997) An introduction to radio astronomy. Cambridge University Press, New YorkGoogle Scholar
  2. Hales A, Wootten A, Butler B (2010) Observing extrasolar planetary systems with ALMA. In: Gozdziewski K, Niedzielski A, Schneider J (eds) Extrasolar planets in multi-body systems: theory and observations. EDP Sciences, Les Ulis, France, vol 42, pp 143–151Google Scholar
  3. Hamaker JP, Bregman JD, Sault RJ (1996) Understanding radio polarimetry. I. Mathematical foundations. Astron Astrophys Suppl Ser 117:137–165CrossRefADSGoogle Scholar
  4. http://iram.fr/IRAMFR/IS/school.htm (Proc. IRAM millimeter interferometry summer schools)
  5. http://www.lesia.obspm.fr/plasma/Goutelas2007/Presentations/ (Proc. XXXth Ecole de Goutelas CNRS/INSU/SF2A, Radioastronomie Basses Fréquences: Instrumentation, Thématiques scientifiques, Projets, 2007)
  6. http://www.obs-nancay.fr (Nançay observatory)
  7. Kassim NE, Weiler KW (eds) (1991) Low frequency astrophysics from space, Lecture notes in physics. Springer, BerlinGoogle Scholar
  8. Kassim NE, Perez MR, Junor W, Henning PA (eds) (2005) From Clark lake to the long wavelength array. ASP conference series, San Francisco, CA, USA, vol 345. http://www.aspbooks.org/a/volumes/table_of_contents/?book_id=55
  9. Kraus JD (1986) Radio astronomy, 2nd edn. McGraw-Hill, New YorkGoogle Scholar
  10. Léna P, Rouan D, Lebrun F, Mignard F, Pelat D (2008) L’observation en astrophysique, 3rd edn. Savoirs Actuels, EDP Sciences, Les Ulis, FranceGoogle Scholar
  11. Rohlfs K, Wilson TL (1996) Tools of radio astronomy, astronomy & astrophysics library, 2nd edn. Springer, HeidelbergGoogle Scholar
  12. Sault RJ, Hamaker JP, Bregman JD (1996) Understanding radio polarimetry. II. Instrumental calibration of an interferometer array. Astron Astrophys Suppl Ser 117:149–159CrossRefADSGoogle Scholar
  13. Stone RG, Weiler KW, Goldstein ML, Bougeret J-L (eds) (2000) Radio astronomy at long wavelengths, vol 119, Geophysical monograph. American Geophysical Union, Washington, DCGoogle Scholar
  14. Zarka P (2007) Plasma interactions of exoplanets with their parent star and associated radio emissions. Planet Space Sci 55:598–617CrossRefADSGoogle Scholar
  15. Zarka P (2010) Instrumentation et Observation en Radioastronomie, Cours du Master 2 Recherche de Sciences de l’;Univers et Technologies Spatiales de l’;Observatoire de Paris. http://www.lesia.obspm.fr/perso/philippe-zarka/CoursPZ/Th2-PZ-2010_1BR.pdf

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.LESIAObservatoire de Paris, CNRS, UPMC, Université Paris DiderotMeudonFrance