sirus-e forusorx (#)
Fr.: cirrus infrarouge
Wispy, extended structures seen above and below the plane of the Galaxy in the infrared maps of the sky (60-100 microns) produced by the → Infrared Astronomical Satellite (IRAS).
→ infrared; L. cirrus "curl, tuft, plant filament like a tuft of hair."
infrared dark cloud (IRDC)
abr-e târik-e forusorx
Fr.: nuage sombre infrarouge
A → dark cloud characterized by a → visual extinction Av≥ 102 mag. IRDCs are opaque even at 8 μm, and can be seen in silhouette against the bright diffuse → mid-infrared emission in the → interstellar medium.
âškârgar-e forusorx (#)
Fr.: détecteur infrarouge
A thermal device for observing and measuring → infrared radiation.
Fr.: émission infrarouge
fozuni-ye forusorx, ferehbud-e ~
Fr.: excès infrarouge
kahkešân-e forusorx (#)
Fr.: galaxie infrarouge
A galaxy that emits most of its energy in the infrared region of the spectrum. Such galaxies are thought to have unusually high rates of star formation and are also described as → starburst galaxies.
tasvirgari-ye forusorx (#)
Fr.: imagerie infrarouge
Imaging with an infrared detector.
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.
forusorx-e miyâni (#)
Fr.: infrarouge moyen
Fr.: rougissement interstellaire
The dimming of light during its travel in the → interstellar medium due to absorption by → intervening → dust grains. Since shorter wavelengths are particularly affected, the spectrum of the light is increasingly dominated by the long wavelength end of the spectrum. As a result, the light is "reddened" as it travels through space. Robert J. Trumpler (1886-1956), a Swiss-American astronomer, was the first to produce a definite evidence of the existence of → interstellar extinction and to estimate its magnitude (1930).
interstellar reddening curve
xam-e sorxeš-e andaraxtari
Fr.: courbe de rougissement interstellaire
A graph showing the relation between → interstellar absorption (in magnitudes) and wavelength.
Fr.: faible décalage vers le rouge
A redshift characterizing a near-by receding object.
luminous infrared galaxy (LIRG)
kahkešân-e forusorx-e tâbân
Fr.: galaxie lumineuse en infrarouge
A galaxy that emits most of its energy in the infrared and whose infrared luminosity (in the 8-1000 µm range) is more than 1011 solar luminosities. → ultraluminous infrared galaxy.
luminous red nova (LRN)
novâ-ye sorx-e tâbân, now-axtar-e ~ ~
Fr.: nova rouge lumineuse
A stellar explosion thought to be caused by the → merger of stars in a → binary system. They are characterized by a distinct red color, and a → light curve that lingers with resurgent brightness in the → infrared. The luminosity of the explosion is between that of a → supernova and a → nova.
forusorx-e miyâni (#)
Fr.: infrarouge moyen
The portion of the → electromagnetic radiation lying between the → near-infrared and the → far-infrared. This covers the wavelength range approximately from 8 to 30 → microns. See also: → infrared radiation, → submillimeter radiation.