Astroparticle Physics

16 Glossary 317High Resolution Imager, focal detector of the X-ray satelliteROSAT.Constant of proportionality between the receding velocity v ofgalaxies and their distance r, v = Hr. According to recentmeasurements the value of the Hubble constant H is about70 (km/s)/Mpc. The inverse Hubble constant corresponds to theage of the universe.The receding velocity of galaxies is proportional to their distance.Space telescope with a mirror diameter of 2.2 m (HST – HubbleSpace Telescope).Hydrogen burning is the fusion of four hydrogen nuclei into a singlehelium nucleus. It starts with the fusion of two protons into adeuterium, positron, and electron neutrino (p +p → d +e + +ν e ).Irvine–Michigan–Brookhaven collaboration for the search of nucleondecay and for neutrino astronomy.A violent inward-bound collapse.Property of matter that requires a force to act on it to change theway it is moving.Hypothetical exponential phase of expansion in the early universestarting at 10 −38 s after the Big Bang and extending up to 10 −36 s.The presently observed isotropy and uniformity of the cosmicbackground radiation can be understood by cosmic inflation.At low momenta quarks are confined in hadrons. They cannot escapetheir hadronic prison.Astronomy in the light of infrared radiation emitted from celestialobjects.A process in which a particle decays or responses to a force due tothe presence of another particle as in a collision.Characteristic collision length for strongly interacting particles inmatter.The gas and dust which exist in the space between the stars.Energy transfer by an energetic electron to a low-energy photon.HRIHubble constant HHubble lawHubble telescopehydrogen burningIIMBimplosioninertiainflationinfrared slaveryinfrared astronomyinteractioninteraction length λinterstellar mediuminverse Compton scattering