Of or pertaining to scales smaller than millimeter.
Fr.: astronomie sub-millimétrique
The study of astronomical objects with → submillimeter waves. As with millimeter-wave astronomy, this part of the spectrum is rich in lines emitted by interstellar molecules and dust.
submillimeter galaxy (SMG)
Fr.: galaxie sub-millimétrique
A member of an extremely luminous population of → high-redshift galaxies which are detected in → submillimeter waves (→ flux density at 850 μm ≥ 3 - 5 mJy). SMGs are powered primarily by star formation rather than an → active galactic nucleus (AGN). Because of their high → dust content, these galaxies emit almost all of their luminosity in the infrared, with a → bolometric luminosity ranging from 1012-1013 → solar luminosities. As such, SMGs resemble → ultraluminous infrared galaxies (ULIRGs), which are almost exclusively → merging galaxies. Indeed, many observations support a → merger origin for SMGs (see, e.g. C.C. Hayward et al. 2011 and references therein, astro-ph/1101.0002).
Fr.: rayonnement sub-millimétrique
Fr.: onde sub-millimétrique
An electromagnetic wave having wavelengths less than one millimeter (frequencies greater than 300 gigahertz).