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Related papers: Triplets of Quasars at high redshift I: Photometri…

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We report detections of six high-redshift (1.8 < z < 6.4), optically luminous, radio-quiet quasars at 350 micron, using the SHARC II bolometer camera at the Caltech Submillimeter Observatory. Our observations double the number of…

Astrophysics · Physics 2009-11-11 A. Beelen , P. Cox , D. J. Benford , C. D. Dowell , A. Kovacs , F. Bertoldi , A. Omont , C. L. Carilli

We present a new catalogue of ~2,400 optically selected quasars with spectroscopic redshifts and X-ray observations from either Chandra or XMM-Newton. The sample can be used to investigate the non-linear relation between the UV and X-ray…

This is the third paper in a series aimed at finding high-redshift quasars from five-color (u'g'r'i'z') imaging data taken along the Celestial Equator by the SDSS during its commissioning phase. In this paper, we first present the…

The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the $z'$ and $R_c$ bands for ~90 square degrees of sky, and supplemental $V$ and $B$ data have been obtained for 33.6 deg$^{2}$. We compile a…

Astrophysics · Physics 2009-11-10 B. C. Hsieh , H. K. C. Yee , H. Lin , M. D. Gladders

We present an analysis of the absorption-line system in the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph spectrum at a redshift of $z_{\rm a}={3.1448}$ associated with the quasar SDSS J122040.23+092326.96, whose…

Astrophysics of Galaxies · Physics 2025-01-03 Qiguo Tian , Lei Hao , Yipeng Zhou , Xiheng Shi , Tuo Ji , Peng Jiang , Lin Lin , Zhenya Zheng , Hongyan Zhou

Large statistical samples of quasar spectra have previously indicated possible cosmological variations in the fine-structure constant, $\alpha$. A smaller sample of higher signal-to-noise ratio spectra, with dedicated calibration, would…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 T. M. Evans , M. T. Murphy , J. B. Whitmore , T. Misawa , M. Centurion , S. D'Odorico , S. Lopez , C. J. A. P. Martins , P. Molaro , P. Petitjean , H. Rahmani , R. Srianand , M. Wendt

We publish the survey for galaxies in 20 fields containing ultraviolet bright quasars (with z_em 0.1 to 0.5) that can be used to study the association between galaxies and absorption systems from the low-z intergalactic medium (IGM). The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 J. Xavier Prochaska , B. Weiner , H. -W. Chen , K. L. Cooksey , J. S. Mulchaey

We present a deep BVrIK multicolor catalog of galaxies in the field of the high redshift (z=4.7) quasar BR 1202-0725. Reliable colors have been measured for galaxies selected down to R=25. The choice of the optical filters has been…

Astrophysics · Physics 2009-10-30 E. Giallongo , S. D'Odorico , A. Fontana , S. Cristiani , E. Egami , E. Hu , R. G. McMahon

We publicly release the spectroscopic and photometric redshift catalog of the sources detected with Chandra in the field of the $z$=6.3 quasar SDSS J1030+0525. This is currently the fifth deepest X-ray field, and reaches a 0.5-2 keV flux…

The UKIRT Infrared Deep Sky Survey (UKIDSS) is the first of a new generation of hemispheric imaging projects to extend the work of the Two Micron All Sky Survey (2MASS) by reaching three magnitudes deeper in YJHK imaging, to K=18.2…

Astrophysics · Physics 2008-11-26 Kuenley Chiu , Gordon T. Richards , Paul C. Hewett , Natasha Maddox

We report the finding of two large-scale structures of galaxies in a 40'x35' field embedded in a 25deg^2 area where two 100 Mpc-scale structures of quasars and MgII absorbers at z~0.8 and z~1.2 have been previously detected. Using deep…

Astrophysics · Physics 2009-11-07 C. P. Haines , L. E. Campusano , R. G. Clowes

We report significant associated clustering in the field of a z=1.226 quasar from the Clowes-Campusano LQG in the form of both a factor ~11 overdensity of I-K>3.75 galaxies and red sequences of 15-18 galaxies at I-K~4.3, V-K~6.9 indicative…

Astrophysics · Physics 2007-05-23 C. P. Haines , R. G. Clowes , L. E. Campusano

We discuss a method aiming to use photometric redshifts in lensing clusters to access the population of distant background sources. The amplification provided by gravitational lensing allows to calibrate photometric redshifts 1 to 3…

Astrophysics · Physics 2007-05-23 Roser Pello , Jean-Paul Kneib , Micol Bolzonella , Joan-Marc Miralles

The clustering properties of faint K<24 galaxies are measured in ultradeep J, H and K near-IR images of the Hubble Deep Field South (HDF-S), obtained with ISAAC at the VLT. A relatively large clustering amplitude is found up to K=24, at a…

Quasars at early redshifts ($z > 6$) with companion galaxies offer unique insights into the growth and evolution of the first supermassive black holes. Here, we report on a 150 ks Chandra observation of PSO J308.0416$-$21.2339, a $z=6.23$…

Francis & Hewett (1993) identified two 10-Mpc scale regions of the high redshift universe that were seemingly very overdense in neutral hydrogen. Subsequent observations showed that at least one of these gas-rich regions enveloped a cluster…

Astrophysics · Physics 2009-10-31 Paul J. Francis , Greg M. Wilson , Bruce E. Woodgate

We cross-match the two currently largest all-sky photometric catalogs, mid-infrared WISE and SuperCOSMOS scans of UKST/POSS-II photographic plates, to obtain a new galaxy sample that covers 3pi steradians. In order to characterize and…

We present constraints on the evolution of large-scale structure from a catalog of 710,000 galaxies with I_AB <= 24 derived from a KPNO 4m CCD imaging survey of a contiguous 4 deg x 4 deg region. The advantage of using large contiguous…

Astrophysics · Physics 2009-10-30 Marc Postman , Tod R. Lauer , Istvan Szapudi , William Oegerle

We present Chandra X-ray imaging and spectroscopy for 14 quasars in spatially resolved pairs, part of a complete sample of binary quasars with small transverse separations drawn from Sloan Digital Sky Survey (DR6) photometry. We find no…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Paul J. Green , Adam D. Myers , Wayne A. Barkhouse , Thomas L. Aldcroft , Markos Trichas , Gordon T. Richards , Angel Ruiz , Philip F. Hopkins

We determine the number counts and z=0-5 luminosity function for a well-defined, homogeneous sample of quasars from the Sloan Digital Sky Survey (SDSS). We conservatively define the most uniform statistical sample possible, consisting of…