1) Mental capacity or endowment.
In a star, nebula, or galaxy, the proportion of the material that is made up of
→ metals, that is elements heavier than → helium.
It is generally denoted by Z.
The term "metallicity" is a misnomer used in astrophysics.
metallicity distribution function (MDF)
karyâ-ye vâbâžeš-e felezigi
Fr.: fonction de distribution de métallicité
Fr.: gradient de métallicité
The decrease in the → abundances of → heavy elements in a → disk galaxy as a function of distance from the center. Radial metallicity gradients are observed in many galaxies, including the → Milky Way and other galaxies of the → Local Group. In the case of the Milky Way, several objects can be used to determine the gradients: → H II regions, → B stars, → Cepheids, → open clusters, and → planetary nebulae. The main diagnostic elements are oxygen, sulphur, neon, and argon in photoionized nebulae, and iron and other elements in Cepheids, open clusters, and stars. Cepheids are probably the most accurate indicators of abundance gradients in the Milky Way. They are bright enough to be observed at large distances, so that accurate distances and spectroscopic abundances of several elements can be obtained. Average abundance gradients are generally between -0.03 → dex/kpc and -0.10 dex/kpc, with a a flattening out of the gradients at large galactocentric distances (≥ 10 kpc). The existence of these gradients offers the opportunity to test models of → chemical evolution of galaxies and stellar → nucleosynthesis.
The smaller number, part, or quantity of a whole.
The quality or state of being → modal.
1) The quality of being → modern.
modulus of rigidity
Fr.: module de rigidité
Same as → shear modulus.
molar heat capacity
gonjâyeš-e garmâyi-ye moli
Fr.: capacité thermique molaire
Fr.: polarisabilité moléculaire
The ability of a molecular entity to be distorted from its normal shape by an external → electric field. When a molecule is subjected to an electric field there is a small displacement of electrical centers which induces a dipole in the molecule. More specifically, the molecular polarizability α is defined as the ratio of the induced → dipole moment (p) to the local electric field (E) that produces this dipole moment: α = p/E (in cgse units).
Fr.: opacité monochromatique
Fr.: relation morphologie-densité
An observationally determined relationship between the → morphological classification of galaxies and the → environments in which they are located. Specifically, the morphology-density relation indicates that early-type galaxies (→ ETG) are preferentially located in high density environments, whereas late-type galaxies (→ LTG) are preferentially found in low density environments. Hence, spiral galaxies are rare in the high densities of clusters and are common in the lower density group environments. Early-type galaxies, on the other hand, are common in clusters and are rarely found in isolation.
Fr.: identité multiplicative
The number which when used as the multiplier of another number leaves the second unchanged; one.
1) The state of being multiple, made of several components.
hâzandegi-ye gune-ye n
Fr.: conductivité de type n
The conductivity in a semiconductor caused by a flow of electrons, whereas p-type conductivity is caused by a flow of holes.
takini-ye berehné (#)
Fr.: singularité nue
A singularity that is not surrounded by an event horizon. It will therefore be visible and communicable to the outside world.
kâvâk-e bini, ~ damâq
Fr.: cavité nasale
1) National status; specifically: a legal relationship involving
allegiance on the part of an individual and usually protection on the
part of the state b : membership in a particular nation.
1) A nebulous form, shape, or mass.