منابع مشابه
Red Quasars Not so Dusty
Webster et al (1995) claimed that up to 80% of QSOs may be obscured by dust. They inferred the presence of this dust from the remarkably broad range of B?K optical-infrared colours of a sample of at-spectrum PKS radio QSOs. If such dust is typical of QSOs, it will have rendered invisible most of those which would otherwise been have detected by optical surveys. We used the William Herschel Tele...
متن کاملRadio-quiet Red Quasars
We have performed a successful targeted search for a population of red, radio-quiet, and probably absorbed quasars. Radio-quiet, optically red ROSAT PSPC X-ray sources brighter than 1 ] 10~13 ergs cm~2 s~1 were searched for red (O[E [2.0, O1 20) counterparts in the Automated Plate-measuring Machine catalog of Palomar Sky Survey objects. Of 45 objects for which we obtained adequate followup opti...
متن کاملExtremely Red and Dusty Galaxies
Preliminary results of a project aiming at unveiling the nature of the extremely red galaxies (ERGs) 1 found in deep optical-NIR surveys are presented. Very little is known about these objects, the critical issue being whether they are old ellipticals at z>1 or distant star-forming galaxies strongly reddened by dust extinction. We expect to shed light onto the unknown nature of these galaxies b...
متن کاملChandra Observations of 12 Luminous Red Quasars
We present results of a study of 12 dust-reddened quasars with 0.4 < z < 2.65 and reddenings in the range 0.15 < E(B − V ) < 1.7. We obtained ACIS-S X-ray spectra of these quasars, estimated the column densities towards them, and hence obtained the gas:dust ratios in the material obscuring the quasar. We detect all but one of the red quasars in the X-rays. Even though there is no obvious correl...
متن کاملSinonasal Teratocarcinosarcoma- A Rare Tumour not so Rarely Misdiagnosed
Sinonasal teratocarcinosarcoma (STCS) is a rare, morphologically heterogeneous and highly aggressive tumour of ambiguous origin. It is characterized by the presence of benign and malignant epithelial, mesenchymal and neuroectodermal components. Because of their rarity and heterogeneity, these lesions are often misdiagnosed, leading to management difficulties. Adequate sampling with a high index...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1998
ISSN: 0035-8711,1365-2966
DOI: 10.1046/j.1365-8711.1998.t01-2-01327.x