1,286 datasets found

We recently presented radio observations of a large sample of radio-loud broad absorption line (BAL) quasars from the Sloan Digital Sky Survey (SDSS) and Faint Images of the...

We analysed the optical and radio properties of lobe-dominated giant-sized (>0.72Mpc) radio quasars and compared the results with those derived for a sample of smaller radio...

We explore the relative strength of the narrow emission lines in a Sloan Digital Sky Survey based sample of broad H{alpha} selected active galactic nuclei (AGN), defined in...

The results of a large area, ~600deg^2^, K-band flux-limited spectroscopic survey for luminous quasars are presented. The survey utilizes the UKIRT Infrared Deep Sky Survey...

We analyze the emission properties of a new sample of 3,579 type 1 AGN, selected from the SDSS DR7 based on the detection of broad H-{alpha} emission. The sample extends over a...

Quasar absorption lines provide a precise test of whether the fine-structure constant, {alpha}, is the same in different places and through cosmological time. We present a new...

We present a catalogue of about six million unresolved photometric detections in the Sloan Digital Sky Survey (SDSS) Seventh Data Release, classifying them into stars, galaxies...

NRAO 530 is an optically violent variable source and has been studied with multi-epoch multifrequency high-resolution very long baseline interferometry (VLBI) observations. NRAO...

We present optical spectra of 403 stars and quasi-stellar objects in order to obtain distance limits towards intermediate- and high-velocity clouds (IHVCs), including new...

We present a panoramic atlas of Spitzer/Infrared Spectrograph (IRS) spectra of extragalactic sources collected from the recent literature, with value-added measurements of their...

We have measured redshifts for 243 z~~3 quasars in nine Very Large Telescope (VLT) Visible Imaging and Multi-Object Spectrograph (VIMOS) Lyman-break galaxy (LBG) redshift survey...

We present a catalogue of 4098 photometrically selected galaxy clusters with a median redshift =0.32 in the 270deg^2^ "Stripe 82" region of the Sloan Digital Sky Survey (SDSS),...

We describe the application of non-negative matrix factorization to generate compact reconstructions of quasar spectra from the Sloan Digital Sky Survey (SDSS), with particular...

We present a new sample of compact steep spectrum (CSS) sources with radio luminosity below 10^26^W/Hz at 1.4GHz; these are called low-luminosity compact (LLC) objects. The...

We present a sample of 8498 quasars with both Sloan Digital Sky Survey (SDSS) ugriz optical and United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) YJHK...

A systematic investigation of the relationship between different redshift estimation schemes for more than 91000 quasars in the Sloan Digital Sky Survey (SDSS) Data Release 6 is...

We report on the near-infrared-selected active galactic nuclei (AGN) candidates extracted from Two Micron All Sky Survey (2MASS)/ROSAT catalogues and discuss their properties....

The cosmic evolution of the metal content of the intergalactic medium puts stringent constraints on the properties of galactic outflows and on the nature of UV background. In...

Arguably the best hope of understanding the tail end of the re-ionization of the intergalactic medium (IGM) at redshift z>6 is through the detection and characterization of...

We have performed a wide-area ultraviolet (UV) imaging survey using the GALaxy Evolution eXplorer to search for bright, point-like UV sources behind M31's extended halo. Our...