kahkešân-e Markarian (#)
Fr.: galaxie de Markarian
A galaxy with abnormally strong emission in the ultraviolet continuum and broad emission lines arising in a bright, semi-stellar nucleus.
Named after B. E. Markarian (1913-1985), an Armenian astronomer who made a catalog of such galaxies (1967-81); → galaxy.
Fr.: chaîne de Markarian
A string of a dozen or so galaxies in the central region of the → Vigo cluster. The chain lies to the right of the cluster's dominant galaxy M87 and extends over nearly 2° on the sky. The chain's brightest galaxies are the lenticulars M84 and M86. At least seven galaxies in the chain appear to move coherently, although others appear to be superposed by chance.
zanjire-ye Markov (#)
Fr.: chaîne de Markov
A → stochastic process, based on the classical → random walk concept, in which the probabilities of occurrence of various future states depend only on the previous state of the system and not on any of earlier states. Also called Markov process and Markovian principle.
Named after Andrey Andreyevich Markov (1856-1922), a Russian mathematician, who introduced this model in 1906; → chain.
Fourth planet from Sun and the seventh largest. Mass 6.42 × 1026 g (0.11 Earth's); radius 3397 km. Mean distance from Sun 1.52 A.U.. Sidereal period 687 days; synodic period 779.9 days. Surface temperature 248 K., rotational period 24h37m22s.6. Obliquity 23°59'. Atmosphere more than 90% CO2, traces of O2, CO, H2O. Two tiny satellites (Phobos and Deimos), both of which are locked in synchronous rotation with Mars.
Late M.E., from L. Mars the Roman god of war, Ares in Gk. mythology.
Bahrâm, from Mid.Pers. Vahrâm, from Vahrân "god of victory," from Av. vərəθraγna- "victory, breaking the defence, the god of victory." The first element vərəθra- "shield, defensive power," cf. Skt. vrtrá- "defence, name of a demon slain by Indra," Arm. vahagan name of a god (loanword from Iranian). The second element γna-, from Av., also O.Pers., jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Mod.Pers. zadan, zan- "to strike, beat;" Mid.Pers. zatan, žatan; Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike," phonos "murder;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *gwhen- "to strike, kill."
The → zero point of elevation on Mars. It is the elevation at which the atmosphere pressure is 6.1 millibars, or 610 → Pascals. Atmosphere pressure has to be used because Mars has no ocean, and "sea level" cannot be used like on Earth. More formally, the datum is a fourth-order, fourth-degree surface of equal → gravitational potential (determined from the Viking orbiter spacecraft) such that the pressure of the atmosphere is 6.1 millibars (source: Lunar and Planetary Institute, USRA).
Fr.: trojan de Mars
Bahrâmi (#), Merixi (#)
Of, relating to, or like the planet → Mars.
M.E. marcien, from L. Marti(us) of, belonging to → Mars + -an a suffix of adjectives.
šaxâne-ye Bahrâmi, šahâbsang-e ~
Fr.: météorite martienne
A piece of rock that was ejected from the Martian surface into space by the impact of an asteroid or comet, and landed on Earth. So far about 100 Martian meteorites have been collected. These meteorites have elemental and isotopic compositions that match those of the Martian crust as measured by NASA's Mars exploration missions.
Fr.: plume de Mars
A slender, cloudy projection sometimes seen to extend from the surface of → Mars to very high altitudes. Noted and confirmed by amateur astronomers on photos of Mars in March 2012, possibly similar plumes have been found on archived images as far back as 1997. The plumes reach 200 km up, which seems too high for them to be related to wind-blown surface dust. Since one plume lasted for more than 10 days, it seemed too long lasting to be related to → aurora. The origin of this phenomenon is not yet known.
1) Having qualities appropriate to or usually associated with a man.
M.E. masculin, from O.Fr. masculin "of the male sex," from L. masculinus "male, of masculine gender," from masculus "male, masculine; worthy of a man," diminutive of mas "male person, male," of unknown origin.
Narin, from nar "male," from Mid.Pers. nar, "male, manly;" Av. nar- "male, man," nairya- "male, manly;" cf. Skt nara- "male, man."
1) A source of very intense, narrow-band, coherent microwave
radiation involving → stimulated emission, as
in the → laser.
Maser stands for Microwave Amplification by Stimulated Emission of Radiation; → laser.
gosil-e meyzeri (#)
Fr.: émission maser
An emission arising from the → maser process.
1) mâsk (#); 2) mâsk zadan (#)
Fr.: 1) masque; 2) masquer
1) Something that serves to cover or conceal.
From M.Fr. masque "covering to hide or guard the face," from It. maschera, from M.L. masca "mask, specter, nightmare," of uncertain origin.
1) Mâsk, loan from Fr., as above; 2) with verb zadan "to make, to do," originally "to strike, beat; to do; to play an instrument" (Mid.Pers. zatan, žatan; O.Pers./Av. jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *gwhen- "to strike, kill").
Fr.: masque, masquage
1) A method of improving → spatial resolution
of images. → pupil masking;
→ unsharp masking.
Verbal noun of → mask.
1) jerm (#), qond (#); 2) tudé (#), anbuh (#)
1) A measure of the amount of material in an object, defined either by the
inertial properties of the object or by its gravitational influence on other
bodies. See also → inertial mass,
→ gravitational mass.
From O.Fr. masse "lump," from L. massa "kneaded dough, lump," from Gk. maza "barley cake, lump, mass, ball," related to massein "to knead."
Jerm, from Ar. jirm.
mass absorption coefficient
hamgar-e daršm-e jermi
Fr.: coefficient d'absorption de masse
A measure of the rate of absorption of radiation, expressed as the linear absorption coefficient divided by the density of the medium through which radiation is passing.
Fr.: défaut de masse
The difference between the rest mass of an atomic nucleus (made up of protons and neutrons) and the sum of the masses of its individual protons and neutrons. The mass difference is equal to the released binding energy. Also called mass deficiency
Fr.: densité massique
The mass per unit area of the ring material, integrated through the thickness of the ring. Sometimes called → surface density (Ellis et al., 2007, Planetary Ring Systems, Springer).
Fr.: écart de masse
1) For → massive stars and → supergiants,
the difference between the → spectroscopic mass and the
→ evolutionary mass. Early studies found that the spectroscopic
mass was systematically less than the evolutionary mass by as much as a factor of 2 for
supergiants. Improvements in the stellar atmosphere models (taking into account
→ line blanketing) have decreased or eliminated the size of the
discrepancy for Galactic stars. There is still a mass discrepancy for the hottest
→ O stars in the → Magellanic Clouds
(See, e.g. Massey et al. 2009, ApJ 692, 618).