Spectro-Polarimetric High-contrast Exoplanet (SPHERE)
Fr.: Spectro-Polarimetric High-contrast Exoplanet (SPHERE)
The → extreme adaptive optics system and → coronagraphic facility at the → European Southern Observatory (ESO) → Very Large Telescope (VLT) (UT3) available from May 2014. Its primary science goal is imaging, low-resolution spectroscopic, and polarimetric characterization of → exoplanetary system at → visible and → near-infrared wavelengths (0.5-2.32 μm). SPHERE is capable of obtaining → diffraction-limited images at 0''.02 to 0''.08 resolution depending on the wavelength. Its → spectral resolution is 30 to 350, depending on the mode.
M.E. thi, thigh(e), the(h), O.E. thioh, theoh; cognate with Du. dij, O.H.G. dioh, O.Norse thjo.
Rân, from Mid.Pers. rân "thigh;" Av. rāna- "the outer part of the thigh."
ultra-high-energy cosmic ray (UHECR)
partowhâ-ye keyhâni-ye ultar-meh-kâruž
Fr.: rayons cosmiques de très haute énergie
A particle belonging to the most energetic population of → cosmic rays with an energy above ~ 1020 → electron-volts. The UHECRs constitute a real challenge for theoretical models, because their acceleration requires extreme conditions hardly fulfilled by known astrophysical objects. See also → UHECR puzzle, → Greisen-Zatsepin-Kuzmin cutoff.
Fr.: neutrino ultra haute énergie
A neutrino particle accelerated to energies above 1018 → electron-volts. They are produced by the interaction of → ultra-high-energy cosmic ray (UHECR)s with the → cosmic microwave background radiation. Also called → cosmogenic neutrinos. See also → Greisen-Zatsepin-Kuzmin limit.
very high frequencies (VHF)
basâmadhâ-ye besyâr bâlâ
Fr.: très hautes fréquences
Radio frequencies in the range 30 to 300 mega Hz.