tâbeš-e forusorx (#)
Fr.: rayonnement infrarouge
That part of the → electromagnetic radiation lying beyond the red, between the radio and the visible regions of the → electromagnetic spectrum. The wavelengths range from about 0.8 → microns (μm) to about 1000 μm. See also: → near-infrared; → mid-infrared; → far-infrared; → submillimeter radiation.
Infrared Space Observatory (ISO)
nepâhešgâh-e fazâyi-ye forusorx
Fr.: Satellite ISO
A European Space Agency satellite which carried the most sensitive infrared telescope ever launched. It operated between November 1995 and April 1998 and made particularly important observations of the dusty regions of the Universe. ISO was equipped with four science instruments: an infrared camera (CAM), a long-wavelength spectrometer (LWS), a photo-polarimeter (PHT), and a short-wavelength spectrometer (SWS). The instruments jointly covered wavelengths from 2.5 to around 240 microns with spatial resolutions ranging from 1.5 arcseconds to 90 arcseconds. Its 60 cm diameter telescope was cooled by superfluid liquid helium to temperatures of 2-4 K. The mission was a great technical, operational and scientific success. During its routine operational phase, ISO successfully made some 30,000 individual imaging, photometric, spectroscopic, and polarimetric observations ranging from objects in our own solar system to the most distant extragalactic sources.
Fr.: relevé infrarouge
Observing a large area of sky (or the whole sky) in infrared wavelengths.
durbin-e forusorx (#), teleskop-e ~ (#)
Fr.: télescope infrarouge
A telescope capable of observing → infrared radiation from astronomical objects.
rowzane-ye forusorx (#)
Fr.: fenêtre infrarouge
A range of infrared wavelengths to which the Earth's atmosphere is relatively transparent, and at which observations can be made from the ground. Infrared windows are found near wavelengths of 1.25, 1.65, 2.2, 3.6, 5.0, 10, 20, and 30 microns, and beyond 300 microns.
Same as → immersion.
rigan bordan, darigidan
To take or receive (property, a right, a title, etc.) by succession or will, as an → heir (Dictionary.com).
Fr.: dont on peut hériter, qui peut hériter
1) Capable of being inherited.
1) Something that is or may be inherited; property passing at the
owner's death to the heir or those entitled to succeed; legacy;
something, as a quality, characteristic, or other immaterial
possession, received from progenitors or predecessors as if by
Verbal noun of → inherit.
The condition or an instance of not being homogeneous.
Lack of homogeneity; something that is not → homogeneous.
Of, pertaining to, or occurring at the beginning.
Âqâzin "pertaing to the beginning," from âqâz "beginning," from Proto-Iranian *āgāza-, from prefix ā- + *gāz- "to take, receive," cf. Sogdian āγāz "beginning, start," pcγz "reception, taking."
Fr.: conditions initiales
1) Conditions at an initial time t = t0 from which a physical system or
a given set of mathematical equations evolves.
jerm-e âqâzin (#)
Fr.: masse initiale
The mass of a star at its arrival on the → main sequence.
initial mass function (IMF)
karyâ-ye âqâzin-e jerm
Fr.: fonction initiale de masse
A mathematical expression describing the relative number of stars found in different ranges of mass for a cluster of stars at the time of its formation. It is defined as φ(log M) = dN / dlog M ∝ M -Γ, where M is the mass of a star and N is the number of stars in a logarithmic mass interval. The value of the slope found by Salpeter (1955) for → low-mass and → intermediate-mass stars in the → solar neighborhood is Γ = 1.35. The IMF can be expressed also in linear mass units: χ(M) = dN / DM ∝ M -α. Note that χ(M) = (1 / M lm 10) φ(log M), and α = Γ + 1. In this formalism the Salpeter slope is α = 2.35. There is a third way for representing the IMF, in which the exponent is x = -α. The IMF is not a single power law over all masses, from → brown dwarfs to → very massive stars (Kroupa, 2002, Science 295, 82). Different slopes have been found for different mass segments, as follows: α = 1.3 for 0.08 ≤ Msolar < 0.5; α = 2.3 for 0.5 ≤ Msolar < 1; α = 2.3 for 1 ≤ Msolar. The IMF at low masses can be fitted by a → lognormal distribution (See Bastian et al., 2010, ARAA 48, 339 and references therein). See also → canonical IMF.
initial phase angle
zâviye-ye fâz-e âqâzin
Fr.: angle de phase initial
The value of the phase corresponding to the origin of time. Same as the → epoch angle.
takini-ye âqâzin (#)
Fr.: singularité initiale
An instant of infinite density, infinite pressure, and infinite temperature where the equations of general relativity break down, if the standard Big Bang theory is extrapolated all the way back to time zero. → singularity.