hot dust-obscured galaxy (HDOG)
kahkešân-e tiré bâ qobâr-e dâq
Fr.: galaxie obscure à poussière chaude
A member of the most extreme galaxies in terms of their luminosities and unusual hot → dust temperatures. The → infrared emission from HDOGs is dominated by obscured accretion onto a central → supermassive black hole (SMBH), in most cases without significant contribution from → star formation. The large contrast between the underlying → host galaxy and the hyper-luminous emission from the → active galactic nucleus (AGN) implies that either the SMBH is much more massive than expected for the stellar mass of its host, or is radiating well above its → Eddington limit. The most extreme of these remarkable systems known is → W2246-0526.
1) tiré (#); 2) tiré kardan (#)
Fr.: 1) obscur; 2) obscurcir
1a) Lacking in light or illumination; dark; dim; murky.
From O.Fr. obscur "dark, dim, not clear," from L. obscurus "covered over, dark, obscure," from ob "over" + -scurus "covered," from PIE *(s)keu- "to cover, conceal;" from which derives also the term → sky.
Tiré, from Mid.Pers. târag "dark, turbid," related to
târik "dark," Mid.Pers. târig "dark," târ "darkness,"
Av. taθra- "darkness," taθrya- "dark,"
cf. Skt. támisrâ- "darkness, dark night,"
L. tenebrae "darkness," Hittite taš(u)uant- "blind," O.H.G.