Radiation astronomy/Continua

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The 15" refractor at Comanche Springs Astronomy Campus had its finder scope (a Stellarvue 80/9D achromat) equipped with a Baader Herschel Solar Wedge and a Solar Continuum Filter for today's transit of Venus. Credit: Jeff Barton from Richardson, TX, USA.{{free media}}

Lyc photon or Ly continuum photon or Lyman continuum photon are a kind of photon emitted from stars. Hydrogen is ionized by absorption of Lyc photons. Lyc photons are in the ultraviolet portion of the electromagnetic spectrum of the hydrogen atom and immediately next to the limit of the Lyman series of the spectrum with wavelengths that are shorter than 91.1267 nanometres and with energy above 13.6 eV.


"The weakening of the neutron shell structure for the nuclei near the neutron drip results from the coupling of the bound neutron states to the particle continuum, which is explicitly taken into account in our [Hartree-Fock-Bogolyubov] HFB calculation (see DFT [Dobaczewski, Flocard and Treiner 1984]). Since the neutron Fermi energy λn is small for such nuclei, the neutron continuum is close in energy to the occupied levels and hence the shell gap cannot be greater than |λn|."[1]

Gamma rays[edit]

Continuum "radiation ... diffuse gamma rays with energies above 10 MeV. In the galaxy these are produced primarily by bremsstrahlung from cosmic ray electrons and from decay in flight of π0's produced by interactions of cosmic ray protons."[2]


The X-ray continuum observed in X-ray astronomy may arise from knock-on collisions of fast protons with atomic electrons.[3]


  1. P. Haensel, J.L. Zdunik, and J. Dobaczewski (September 1989). "Composition and equation of state of cold catalyzed matter below neutron drip". Astronomy and Astrophysics 222 (1-2): 353-7. http://adsabs.harvard.edu/abs/1989A&A...222..353H. Retrieved 2014-01-22. 
  2. Thomas K. Gaisser (1990). Cosmic Rays and Particle Physics. Cambridge University Press. p. 279. ISBN 0521339316. Retrieved 2014-01-11.
  3. P Morrison (1967). "Extrasolar X-ray Sources". Annual Reviews of Astronomy and Astrophysics 5 (1): 325. doi:10.1146/annurev.aa.05.090167.001545.