CYBERSKA

 A Cyberinfrastructure platform to meet the needs of data intensive radio astronomy on route to the SKA

Results for "sdss"

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  • Radiogalaxies in the Sloan Digital Sky Survey: spectral index-environment correlations

    We analyze optical and radio properties of radiogalaxies detected in the Sloan Digital Sky Survey (SDSS). The sample of radio sources are selected from the catalogue of Kimball & Ivezi\'c (2008) with flux densities at 325, 1400 and 4850 MHz, using WENSS, NVSS and GB6 radio surveys and from fl...

    Tags: sdss, wenss, nvss, uss, alpha, spectral index, gb6

    3078 days ago

  • Radio sources with ultra-high polarisation

    A sample of 129 unresolved radio sources with ultra-high linear polarisation (>30 per cent) has been selected from the NVSS (NRAO VLA Sky Survey). Such high average linear polarisation is unusual in extragalactic sources. Higher resolution ATCA (Australia Telescope Compact Array) and VLA (Very...

    Tags: mnras, arxiv, polarization, agn, nvss, sdss, vla, atca, galaxy, unresolved

    3078 days ago

  • A GBT Survey for HI 21 cm Absorption in the Disks and Halos of Low-Redshift Galaxies

    We present an HI 21 cm absorption survey with the Green Bank Telescope (GBT) of galaxy-quasar pairs selected by combining data from the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. Our sample consists of 23 sightlines through 15 low-r...

    Tags: cosmology, extragalactic, vla, gbt, lyman, arxiv, sdss

    3069 days ago

  • Low Surface Brightness Galaxies in the SDSS: the link between environment, star-forming properties and AGN

    Using the Sloan Digital Sky Survey (SDSS) data release 4 (DR 4), we investigate the spatial distribution of low and high surface brightness galaxies (LSBs and HSBs, respectively). In particular, we focus our attention on the influence of interactions between galaxies on the star formation strengt...

    Tags: sdss, agn, galaxies

    3067 days ago

  • The Use of Scientific Data: A Content Analysis

    Nowadays, science has been coming into a new paradigm, called data-intensive science. While current studies of the new phenomenon focused on building up infrastructure for this new paradigm, yet a few studies concern users of scientific data, particularly their usage practices in the newly emergi...

    Tags: digital libraries, ieee e-science, sdss, work flow, data, objects, arxiv

    3065 days ago

  • Multiwavelength Observations of Radio-quiet Quasars with Weak Emission Lines

    We present radio and X-ray observations, as well as optical light curves, for a subset of 26 BL Lac candidates from the Sloan Digital Sky Survey (SDSS) lacking strong radio emission and with z<2.2. Half of these 26 objects are shown to be stars, galaxies, or absorbed quasars. We conclude that ...

    Tags: arxivs, mnras, agn, xray, sdss

    3063 days ago

  • Lessons Learned from the SDSS Catalog Archive Server

    The SDSS is one of the first very large archives in astronomy and other sciences, as we enter the era of data-intensive science. Here the authors summarize some of the important and generally applicable insights they have gained (often the hard way!) over the past decade of SDSS development.

    Tags: sdss, archive, server, catalogue, catalog

    3054 days ago

  • Galaxy Cluster Environments of Radio Sources

    Using the Sloan Digital Sky Survey (SDSS) and the FIRST (Faint Images of the Radio Sky at Twenty Centimeters) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between ...

    Tags: fri, frii, sdss, first, double sources, extended, clusters, arxiv

    3053 days ago

  • Clustering of radio galaxies and quasars

    We compute the cross-correlation between a sample of 14 000 radio-loud active galactic nuclei (RLAGN) with redshifts between 0.4 and 0.8 selected from the Sloan Digital Sky Survey and a reference sample of 1.2 million luminous red galaxies in the same redshift range. We quantify how the clus...

    Tags: agn, sdss

    3047 days ago