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    Discovery of six high-redshift quasars with the Lijiang 2.4m telescope and the Multiple Mirror Telescope

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    Quasars with redshifts greater than 4 are rare, and can be used to probe the structure and evolution of the early universe. Here we report the discovery of six new quasars with ii-band magnitudes brighter than 19.5 and redshifts between 2.4 and 4.6 from the YFOSC spectroscopy of the Lijiang 2.4m telescope in February, 2012. These quasars are in the list of z>3.6z>3.6 quasar candidates selected by using our proposed J−K/i−YJ-K/i-Y criterion and the photometric redshift estimations from the SDSS optical and UKIDSS near-IR photometric data. Nine candidates were observed by YFOSC, and five among six new quasars were identified as z>3.6z>3.6 quasars. One of the other three objects was identified as a star and the other two were unidentified due to the lower signal-to-noise ratio of their spectra. This is the first time that z>4z>4 quasars have been discovered using a telescope in China. Thanks to the Chinese Telescope Access Program (TAP), the redshift of 4.6 for one of these quasars was confirmed by the Multiple Mirror Telescope (MMT) Red Channel spectroscopy. The continuum and emission line properties of these six quasars, as well as their central black hole masses and Eddington ratios, were obtained.Comment: 7 pages, 2 figures, published in Research in Astronomy and Astrophysics (RAA) as a lette

    On q-deformed infinite-dimensional n-algebra

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    The qq-deformation of the infinite-dimensional nn-algebra is investigated. Based on the structure of the qq-deformed Virasoro-Witt algebra, we derive a nontrivial qq-deformed Virasoro-Witt nn-algebra which is nothing but a sh-nn-Lie algebra. Furthermore in terms of the pseud-differential operators on the quantum plane, we construct the (co)sine nn-algebra and the qq-deformed SDiff(T2)SDiff(T^2) nn-algebra. We prove that they are the sh-nn-Lie algebras for the case of even nn. An explicit physical realization of the (co)sine nn-algebra is given.Comment: 22 page
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