emission+of+rays
41fluorescence — Emission of a longer wavelength radiation by a substance as a consequence of absorption of energy from a shorter wavelength radiation, continuing only as long as the stimulus is present; distinguished from phosphorescence, which …
42radiation — radiational, adj. /ray dee ay sheuhn/, n. 1. Physics. a. the process in which energy is emitted as particles or waves. b. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and… …
43spectroscopy — spectroscopist /spek tros keuh pist/, n. /spek tros keuh pee, spek treuh skoh pee/, n. the science that deals with the use of the spectroscope and with spectrum analysis. [1865 70; SPECTRO + SCOPY] * * * Branch of analysis devoted to identifying… …
44X-ray astronomy — X rays start at 0.008 nm and extend across the electromagnetic spectrum to 8 nm, over which the Earth s atmosphere is opaque. X ray astronomy is an observational branch of astronomy which deals with the study of X ray observation and detection… …
45electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
46cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
47light — light1 lightful, adj. lightfully, adv. /luyt/, n., adj., lighter, lightest, v., lighted or lit, lighting. n. 1. something that makes things visible or affords illumination: All colors depend on light. 2. Physics …
48Radioactive decay — For particle decay in a more general context, see Particle decay. For more information on hazards of various kinds of radiation from decay, see Ionizing radiation. Radioactive redirects here. For other uses, see Radioactive (disambiguation).… …
49nebula — nebular, adj. /neb yeuh leuh/, n., pl. nebulae / lee , luy /, nebulas. 1. Astron. a. Also called diffuse nebula. a cloud of interstellar gas and dust. Cf. dark nebula, emission nebula, reflection nebula …
50Cygnus X-1 — For other uses, see Cygnus X 1 (disambiguation). HDE 226868 HDE 226868 (not shown) is located next to the star η (lower center) in this map of constellation Cygnus …
