منابع مشابه
CC Boötis: QSO, Not Variable Halo Giant
The poorly-studied, faint (18 < mpg < 19.5) variable star CC Boötis has been noted in the literature as a candidate for a halo red giant. It proves instead to be a quasi-stellar object of redshift z = 0.172, and is detected as an X-ray source by ROSAT. In addition to its odd heritage, CC Boo exhibits unusually high amplitude optical variability for an optically-selected QSO.
متن کامل06 3 v 1 7 A pr 1 99 7 CC Boötis : QSO , Not Variable Halo Giant
The poorly-studied, faint (18 < m pg < 19.5) variable star CC Boötis has been noted in the literature as a candidate for a halo red giant. It proves instead to be a quasi-stellar object of redshift z = 0.172, and is detected as an X-ray source by ROSAT. In addition to its odd heritage, CC Boo exhibits unusually high amplitude optical variability for an optically-selected QSO.
متن کاملThe giant radio halo in Abell 2163
New radio data is presented for the rich cluster Abell 2163. The cluster radio emission is characterized by the presence of a radio halo, which is one of the most powerful and extended halos known so far. In the NE peripheral cluster region, we also detect diffuse elongated emission, which we classify as a cluster relic. The cluster A2163 is very hot and luminous in X-ray. Its central region is...
متن کاملConstraints on the correlation between QSO luminosity and host halo mass from high-redshift quasar clustering
Recent measurements of high-redshift QSO clustering from the Sloan Digital Sky Survey indicate that QSOs at z ∼ 4 have a bias 〈b〉 ≃ 14. We find that this extremely high clustering amplitude, combined with the corresponding space density, constrains the dispersion in the L−Mh relation to be less than 50% at 99% confidence for the most conservative case of a 100% duty cycle. This upper limit to t...
متن کاملA Giant Radio Halo in the Massive and Merging Cluster
We report on the detection of diffuse radio emission in the X-ray luminous and massive galaxy cluster A 1351 (z=0.322) using archival Very Large Array data at 1.4 GHz. Given its central location, morphology and Mpc-scale extent, we classify the diffuse source as a giant radio halo. X-ray and weak lensing studies show A 1351 to be a system undergoing a major merger. The halo is associated to the...
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ژورنال
عنوان ژورنال: Publications of the Astronomical Society of the Pacific
سال: 1997
ISSN: 0004-6280,1538-3873
DOI: 10.1086/133930